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Prior to commit 1f4a4a19508d ("scsi: ibmvfc: Complete commands outside the
host/queue lock") responses to commands were completed sequentially with
the host lock held such that a command had a basic binary state of active
or free. It was therefore a simple affair of ensuring the assocaiated
ibmvfc_event to a VIOS response was valid by testing that it was not
already free. The lock relexation work to complete commands outside the
lock inadverdently made it a trinary command state such that a command is
either in flight, received and being completed, or completed and now
free. This breaks the stale command detection logic as a command may be
still marked active and been placed on the delayed completion list when a
second stale response for the same command arrives. This can lead to double
completions and list corruption. This issue was exposed by a recent VIOS
regression were a missing memory barrier could occasionally result in the
ibmvfc client receiving a duplicate response for the same command.
Fix the issue by introducing the atomic ibmvfc_event.active to track the
trinary state of a command. The state is explicitly set to 1 when a command
is successfully sent. The CRQ response handlers use
atomic_dec_if_positive() to test for stale responses and correctly
transition to the completion state when a active command is received.
Finally, atomic_dec_and_test() is used to sanity check transistions when
commands are freed as a result of a completion, or moved to the purge list
as a result of error handling or adapter reset.
Link: https://lore.kernel.org/r/[email protected]
Fixes: 1f4a4a19508d ("scsi: ibmvfc: Complete commands outside the host/queue lock")
Cc: [email protected]
Signed-off-by: Tyrel Datwyler <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
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Avoid printing a 'target allocation failed' error if the driver
target_alloc() callback function returns -ENXIO. This return value
indicates that the corresponding H:C:T:L entry is empty.
Removing this error reduces the scan time if the user issues SCAN_WILD_CARD
scan operation through sysfs parameter on a host with a lot of empty
H:C:T:L entries.
Avoiding the printk on -ENXIO matches the behavior of the other callback
functions during scanning.
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sreekanth Reddy <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
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The following BUG_ON() was observed during RDAC scan:
[595952.944297] kernel BUG at drivers/scsi/device_handler/scsi_dh_rdac.c:427!
[595952.951143] Internal error: Oops - BUG: 0 [#1] SMP
......
[595953.251065] Call trace:
[595953.259054] check_ownership+0xb0/0x118
[595953.269794] rdac_bus_attach+0x1f0/0x4b0
[595953.273787] scsi_dh_handler_attach+0x3c/0xe8
[595953.278211] scsi_dh_add_device+0xc4/0xe8
[595953.282291] scsi_sysfs_add_sdev+0x8c/0x2a8
[595953.286544] scsi_probe_and_add_lun+0x9fc/0xd00
[595953.291142] __scsi_scan_target+0x598/0x630
[595953.295395] scsi_scan_target+0x120/0x130
[595953.299481] fc_user_scan+0x1a0/0x1c0 [scsi_transport_fc]
[595953.304944] store_scan+0xb0/0x108
[595953.308420] dev_attr_store+0x44/0x60
[595953.312160] sysfs_kf_write+0x58/0x80
[595953.315893] kernfs_fop_write+0xe8/0x1f0
[595953.319888] __vfs_write+0x60/0x190
[595953.323448] vfs_write+0xac/0x1c0
[595953.326836] ksys_write+0x74/0xf0
[595953.330221] __arm64_sys_write+0x24/0x30
Code is in check_ownership:
list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
/* h->sdev should always be valid */
BUG_ON(!tmp->sdev);
tmp->sdev->access_state = access_state;
}
rdac_bus_attach
initialize_controller
list_add_rcu(&h->node, &h->ctlr->dh_list);
h->sdev = sdev;
rdac_bus_detach
list_del_rcu(&h->node);
h->sdev = NULL;
Fix the race between rdac_bus_attach() and rdac_bus_detach() where h->sdev
is NULL when processing the RDAC attach.
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Ye Bin <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
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Added macros for date and version
Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
Signed-off-by: Edmund Dea <[email protected]>
Signed-off-by: Anitha Chrisanthus <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
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There's an undocumented dependency between LCD layer enable bits [2-5]
and the AXI pipelined read enable bit [28] in the LCD_CONTROL register.
The proper order of operation is:
1) Clear AXI pipelined read enable bit
2) Set LCD layers
3) Set AXI pipelined read enable bit
With this update, LCD can start DMA when TVDDCV is reduced down to 700mV.
Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
Signed-off-by: Edmund Dea <[email protected]>
Signed-off-by: Anitha Chrisanthus <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
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Fix the following fallthrough warning (on ARM):
drivers/scsi/arm/fas216.c:1379:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
default:
^
drivers/scsi/arm/fas216.c:1379:2: note: insert 'break;' to avoid fall-through
default:
^
break;
Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Gustavo A. R. Silva <[email protected]>
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Fix the following fallthrough warning (on ARM):
drivers/scsi/arm/acornscsi.c:2651:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
case res_success:
^
drivers/scsi/arm/acornscsi.c:2651:2: note: insert '__attribute__((fallthrough));' to silence this warning
case res_success:
^
__attribute__((fallthrough));
drivers/scsi/arm/acornscsi.c:2651:2: note: insert 'break;' to avoid fall-through
case res_success:
^
break;
Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Gustavo A. R. Silva <[email protected]>
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Fix the following fallthrough warning:
arch/arm/mach-rpc/riscpc.c:52:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
default:
^
arch/arm/mach-rpc/riscpc.c:52:2: note: insert 'break;' to avoid fall-through
default:
^
break;
Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Gustavo A. R. Silva <[email protected]>
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Pull kvm fixes from Paolo Bonzini:
"ARM:
- Fix MTE shared page detection
- Enable selftest's use of PMU registers when asked to
s390:
- restore 5.13 debugfs names
x86:
- fix sizes for vcpu-id indexed arrays
- fixes for AMD virtualized LAPIC (AVIC)
- other small bugfixes
Generic:
- access tracking performance test
- dirty_log_perf_test command line parsing fix
- Fix selftest use of obsolete pthread_yield() in favour of
sched_yield()
- use cpu_relax when halt polling
- fixed missing KVM_CLEAR_DIRTY_LOG compat ioctl"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: add missing compat KVM_CLEAR_DIRTY_LOG
KVM: use cpu_relax when halt polling
KVM: SVM: use vmcb01 in svm_refresh_apicv_exec_ctrl
KVM: SVM: tweak warning about enabled AVIC on nested entry
KVM: SVM: svm_set_vintr don't warn if AVIC is active but is about to be deactivated
KVM: s390: restore old debugfs names
KVM: SVM: delay svm_vcpu_init_msrpm after svm->vmcb is initialized
KVM: selftests: Introduce access_tracking_perf_test
KVM: selftests: Fix missing break in dirty_log_perf_test arg parsing
x86/kvm: fix vcpu-id indexed array sizes
KVM: x86: Check the right feature bit for MSR_KVM_ASYNC_PF_ACK access
docs: virt: kvm: api.rst: replace some characters
KVM: Documentation: Fix KVM_CAP_ENFORCE_PV_FEATURE_CPUID name
KVM: nSVM: Swap the parameter order for svm_copy_vmrun_state()/svm_copy_vmloadsave_state()
KVM: nSVM: Rename nested_svm_vmloadsave() to svm_copy_vmloadsave_state()
KVM: arm64: selftests: get-reg-list: actually enable pmu regs in pmu sublist
KVM: selftests: change pthread_yield to sched_yield
KVM: arm64: Fix detection of shared VMAs on guest fault
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git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
Pull m68knommu fix from Greg Ungerer:
"A single compile time fix"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68k/coldfire: change pll var. to clk_pll
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While reviewing the buffer item recovery code, the thought occurred to
me: in V5 filesystems we use log sequence number (LSN) tracking to avoid
replaying older metadata updates against newer log items. However, we
use the magic number of the ondisk buffer to find the LSN of the ondisk
metadata, which means that if an attacker can control the layout of the
realtime device precisely enough that the start of an rt bitmap block
matches the magic and UUID of some other kind of block, they can control
the purported LSN of that spoofed block and thereby break log replay.
Since realtime bitmap and summary blocks don't have headers at all, we
have no way to tell if a block really should be replayed. The best we
can do is replay unconditionally and hope for the best.
Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Dave Chinner <[email protected]>
Reviewed-by: Carlos Maiolino <[email protected]>
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From the department of "generic/482 keeps on giving", we bring you
another tail update race condition:
iclog:
S1 C1
+-----------------------+-----------------------+
S2 EOIC
Two checkpoints in a single iclog. One is complete, the other just
contains the start record and overruns into a new iclog.
Timeline:
Before S1: Cache flush, log tail = X
At S1: Metadata stable, write start record and checkpoint
At C1: Write commit record, set NEED_FUA
Single iclog checkpoint, so no need for NEED_FLUSH
Log tail still = X, so no need for NEED_FLUSH
After C1,
Before S2: Cache flush, log tail = X
At S2: Metadata stable, write start record and checkpoint
After S2: Log tail moves to X+1
At EOIC: End of iclog, more journal data to write
Releases iclog
Not a commit iclog, so no need for NEED_FLUSH
Writes log tail X+1 into iclog.
At this point, the iclog has tail X+1 and NEED_FUA set. There has
been no cache flush for the metadata between X and X+1, and the
iclog writes the new tail permanently to the log. THis is sufficient
to violate on disk metadata/journal ordering.
We have two options here. The first is to detect this case in some
manner and ensure that the partial checkpoint write sets NEED_FLUSH
when the iclog is already marked NEED_FUA and the log tail changes.
This seems somewhat fragile and quite complex to get right, and it
doesn't actually make it obvious what underlying problem it is
actually addressing from reading the code.
The second option seems much cleaner to me, because it is derived
directly from the requirements of the C1 commit record in the iclog.
That is, when we write this commit record to the iclog, we've
guaranteed that the metadata/data ordering is correct for tail
update purposes. Hence if we only write the log tail into the iclog
for the *first* commit record rather than the log tail at the last
release, we guarantee that the log tail does not move past where the
the first commit record in the log expects it to be.
IOWs, taking the first option means that replay of C1 becomes
dependent on future operations doing the right thing, not just the
C1 checkpoint itself doing the right thing. This makes log recovery
almost impossible to reason about because now we have to take into
account what might or might not have happened in the future when
looking at checkpoints in the log rather than just having to
reconstruct the past...
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
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Because I cannot tell if the NEED_FLUSH flag is being set correctly
by the log force and CIL push machinery without it.
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
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From the department of "WTAF? How did we miss that!?"...
When we are recovering a buffer, the first thing we do is check the
buffer magic number and extract the LSN from the buffer. If the LSN
is older than the current LSN, we replay the modification to it. If
the metadata on disk is newer than the transaction in the log, we
skip it. This is a fundamental v5 filesystem metadata recovery
behaviour.
generic/482 failed with an attribute writeback failure during log
recovery. The write verifier caught the corruption before it got
written to disk, and the attr buffer dump looked like:
XFS (dm-3): Metadata corruption detected at xfs_attr3_leaf_verify+0x275/0x2e0, xfs_attr3_leaf block 0x19be8
XFS (dm-3): Unmount and run xfs_repair
XFS (dm-3): First 128 bytes of corrupted metadata buffer:
00000000: 00 00 00 00 00 00 00 00 3b ee 00 00 4d 2a 01 e1 ........;...M*..
00000010: 00 00 00 00 00 01 9b e8 00 00 00 01 00 00 05 38 ...............8
^^^^^^^^^^^^^^^^^^^^^^^
00000020: df 39 5e 51 58 ac 44 b6 8d c5 e7 10 44 09 bc 17 .9^QX.D.....D...
00000030: 00 00 00 00 00 02 00 83 00 03 00 cc 0f 24 01 00 .............$..
00000040: 00 68 0e bc 0f c8 00 10 00 00 00 00 00 00 00 00 .h..............
00000050: 00 00 3c 31 0f 24 01 00 00 00 3c 32 0f 88 01 00 ..<1.$....<2....
00000060: 00 00 3c 33 0f d8 01 00 00 00 00 00 00 00 00 00 ..<3............
00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
.....
The highlighted bytes are the LSN that was replayed into the
buffer: 0x100000538. This is cycle 1, block 0x538. Prior to replay,
that block on disk looks like this:
$ sudo xfs_db -c "fsb 0x417d" -c "type attr3" -c p /dev/mapper/thin-vol
hdr.info.hdr.forw = 0
hdr.info.hdr.back = 0
hdr.info.hdr.magic = 0x3bee
hdr.info.crc = 0xb5af0bc6 (correct)
hdr.info.bno = 105448
hdr.info.lsn = 0x100000900
^^^^^^^^^^^
hdr.info.uuid = df395e51-58ac-44b6-8dc5-e7104409bc17
hdr.info.owner = 131203
hdr.count = 2
hdr.usedbytes = 120
hdr.firstused = 3796
hdr.holes = 1
hdr.freemap[0-2] = [base,size]
Note the LSN stamped into the buffer on disk: 1/0x900. The version
on disk is much newer than the log transaction that was being
replayed. That's a bug, and should -never- happen.
So I immediately went to look at xlog_recover_get_buf_lsn() to check
that we handled the LSN correctly. I was wondering if there was a
similar "two commits with the same start LSN skips the second
replay" problem with buffers. I didn't get that far, because I found
a much more basic, rudimentary bug: xlog_recover_get_buf_lsn()
doesn't recognise buffers with XFS_ATTR3_LEAF_MAGIC set in them!!!
IOWs, attr3 leaf buffers fall through the magic number checks
unrecognised, so trigger the "recover immediately" behaviour instead
of undergoing an LSN check. IOWs, we incorrectly replay ATTR3 leaf
buffers and that causes silent on disk corruption of inode attribute
forks and potentially other things....
Git history shows this is *another* zero day bug, this time
introduced in commit 50d5c8d8e938 ("xfs: check LSN ordering for v5
superblocks during recovery") which failed to handle the attr3 leaf
buffers in recovery. And we've failed to handle them ever since...
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
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When we log an inode, we format the "log inode" core and set an LSN
in that inode core. We do that via xfs_inode_item_format_core(),
which calls:
xfs_inode_to_log_dinode(ip, dic, ip->i_itemp->ili_item.li_lsn);
to format the log inode. It writes the LSN from the inode item into
the log inode, and if recovery decides the inode item needs to be
replayed, it recovers the log inode LSN field and writes it into the
on disk inode LSN field.
Now this might seem like a reasonable thing to do, but it is wrong
on multiple levels. Firstly, if the item is not yet in the AIL,
item->li_lsn is zero. i.e. the first time the inode it is logged and
formatted, the LSN we write into the log inode will be zero. If we
only log it once, recovery will run and can write this zero LSN into
the inode.
This means that the next time the inode is logged and log recovery
runs, it will *always* replay changes to the inode regardless of
whether the inode is newer on disk than the version in the log and
that violates the entire purpose of recording the LSN in the inode
at writeback time (i.e. to stop it going backwards in time on disk
during recovery).
Secondly, if we commit the CIL to the journal so the inode item
moves to the AIL, and then relog the inode, the LSN that gets
stamped into the log inode will be the LSN of the inode's current
location in the AIL, not it's age on disk. And it's not the LSN that
will be associated with the current change. That means when log
recovery replays this inode item, the LSN that ends up on disk is
the LSN for the previous changes in the log, not the current
changes being replayed. IOWs, after recovery the LSN on disk is not
in sync with the LSN of the modifications that were replayed into
the inode. This, again, violates the recovery ordering semantics
that on-disk writeback LSNs provide.
Hence the inode LSN in the log dinode is -always- invalid.
Thirdly, recovery actually has the LSN of the log transaction it is
replaying right at hand - it uses it to determine if it should
replay the inode by comparing it to the on-disk inode's LSN. But it
doesn't use that LSN to stamp the LSN into the inode which will be
written back when the transaction is fully replayed. It uses the one
in the log dinode, which we know is always going to be incorrect.
Looking back at the change history, the inode logging was broken by
commit 93f958f9c41f ("xfs: cull unnecessary icdinode fields") way
back in 2016 by a stupid idiot who thought he knew how this code
worked. i.e. me. That commit replaced an in memory di_lsn field that
was updated only at inode writeback time from the inode item.li_lsn
value - and hence always contained the same LSN that appeared in the
on-disk inode - with a read of the inode item LSN at inode format
time. CLearly these are not the same thing.
Before 93f958f9c41f, the log recovery behaviour was irrelevant,
because the LSN in the log inode always matched the on-disk LSN at
the time the inode was logged, hence recovery of the transaction
would never make the on-disk LSN in the inode go backwards or get
out of sync.
A symptom of the problem is this, caught from a failure of
generic/482. Before log recovery, the inode has been allocated but
never used:
xfs_db> inode 393388
xfs_db> p
core.magic = 0x494e
core.mode = 0
....
v3.crc = 0x99126961 (correct)
v3.change_count = 0
v3.lsn = 0
v3.flags2 = 0
v3.cowextsize = 0
v3.crtime.sec = Thu Jan 1 10:00:00 1970
v3.crtime.nsec = 0
After log recovery:
xfs_db> p
core.magic = 0x494e
core.mode = 020444
....
v3.crc = 0x23e68f23 (correct)
v3.change_count = 2
v3.lsn = 0
v3.flags2 = 0
v3.cowextsize = 0
v3.crtime.sec = Thu Jul 22 17:03:03 2021
v3.crtime.nsec = 751000000
...
You can see that the LSN of the on-disk inode is 0, even though it
clearly has been written to disk. I point out this inode, because
the generic/482 failure occurred because several adjacent inodes in
this specific inode cluster were not replayed correctly and still
appeared to be zero on disk when all the other metadata (inobt,
finobt, directories, etc) indicated they should be allocated and
written back.
The fix for this is two-fold. The first is that we need to either
revert the LSN changes in 93f958f9c41f or stop logging the inode LSN
altogether. If we do the former, log recovery does not need to
change but we add 8 bytes of memory per inode to store what is
largely a write-only inode field. If we do the latter, log recovery
needs to stamp the on-disk inode in the same manner that inode
writeback does.
I prefer the latter, because we shouldn't really be trying to log
and replay changes to the on disk LSN as the on-disk value is the
canonical source of the on-disk version of the inode. It also
matches the way we recover buffer items - we create a buf_log_item
that carries the current recovery transaction LSN that gets stamped
into the buffer by the write verifier when it gets written back
when the transaction is fully recovered.
However, this might break log recovery on older kernels even more,
so I'm going to simply ignore the logged value in recovery and stamp
the on-disk inode with the LSN of the transaction being recovered
that will trigger writeback on transaction recovery completion. This
will ensure that the on-disk inode LSN always reflects the LSN of
the last change that was written to disk, regardless of whether it
comes from log recovery or runtime writeback.
Fixes: 93f958f9c41f ("xfs: cull unnecessary icdinode fields")
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
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Before waiting on a iclog in xfs_log_force_lsn(), we don't check to
see if the iclog has already been completed and the contents on
stable storage. We check for completed iclogs in xfs_log_force(), so
we should do the same thing for xfs_log_force_lsn().
This fixed some random up-to-30s pauses seen in unmounting
filesystems in some tests. A log force ends up waiting on completed
iclog, and that doesn't then get flushed (and hence the log force
get completed) until the background log worker issues a log force
that flushes the iclog in question. Then the unmount unblocks and
continues.
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
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After fixing the tail_lsn vs cache flush race, generic/482 continued
to fail in a similar way where cache flushes were missing before
iclog FUA writes. Tracing of iclog state changes during the fsstress
workload portion of the test (via xlog_iclog* events) indicated that
iclog writes were coming from two sources - CIL pushes and log
forces (due to fsync/O_SYNC operations). All of the cases where a
recovery problem was triggered indicated that the log force was the
source of the iclog write that was not preceeded by a cache flush.
This was an oversight in the modifications made in commit
eef983ffeae7 ("xfs: journal IO cache flush reductions"). Log forces
for fsync imply a data device cache flush has been issued if an
iclog was flushed to disk and is indicated to the caller via the
log_flushed parameter so they can elide the device cache flush if
the journal issued one.
The change in eef983ffeae7 results in iclogs only issuing a cache
flush if XLOG_ICL_NEED_FLUSH is set on the iclog, but this was not
added to the iclogs that the log force code flushes to disk. Hence
log forces are no longer guaranteeing that a cache flush is issued,
hence opening up a potential on-disk ordering failure.
Log forces should also set XLOG_ICL_NEED_FUA as well to ensure that
the actual iclogs it forces to the journal are also on stable
storage before it returns to the caller.
This patch introduces the xlog_force_iclog() helper function to
encapsulate the process of taking a reference to an iclog, switching
its state if WANT_SYNC and flushing it to stable storage correctly.
Both xfs_log_force() and xfs_log_force_lsn() are converted to use
it, as is xlog_unmount_write() which has an elaborate method of
doing exactly the same "write this iclog to stable storage"
operation.
Further, if the log force code needs to wait on a iclog in the
WANT_SYNC state, it needs to ensure that iclog also results in a
cache flush being issued. This covers the case where the iclog
contains the commit record of the CIL flush that the log force
triggered, but it hasn't been written yet because there is still an
active reference to the iclog.
Note: this whole cache flush whack-a-mole patch is a result of log
forces still being iclog state centric rather than being CIL
sequence centric. Most of this nasty code will go away in future
when log forces are converted to wait on CIL sequence push
completion rather than iclog completion. With the CIL push algorithm
guaranteeing that the CIL checkpoint is fully on stable storage when
it completes, we no longer need to iterate iclogs and push them to
ensure a CIL sequence push has completed and so all this nasty iclog
iteration and flushing code will go away.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
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We force iclogs in several places - we need them all to have the
same cache flush semantics, so start by factoring out the iclog
force into a common helper.
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
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There is a race between the new CIL async data device metadata IO
completion cache flush and the log tail in the iclog the flush
covers being updated. This can be seen by repeating generic/482 in a
loop and eventually log recovery fails with a failures such as this:
XFS (dm-3): Starting recovery (logdev: internal)
XFS (dm-3): bad inode magic/vsn daddr 228352 #0 (magic=0)
XFS (dm-3): Metadata corruption detected at xfs_inode_buf_verify+0x180/0x190, xfs_inode block 0x37c00 xfs_inode_buf_verify
XFS (dm-3): Unmount and run xfs_repair
XFS (dm-3): First 128 bytes of corrupted metadata buffer:
00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
XFS (dm-3): metadata I/O error in "xlog_recover_items_pass2+0x55/0xc0" at daddr 0x37c00 len 32 error 117
Analysis of the logwrite replay shows that there were no writes to
the data device between the FUA @ write 124 and the FUA at write @
125, but log recovery @ 125 failed. The difference was the one log
write @ 125 moved the tail of the log forwards from (1,8) to (1,32)
and so the inode create intent in (1,8) was not replayed and so the
inode cluster was zero on disk when replay of the first inode item
in (1,32) was attempted.
What this meant was that the journal write that occurred at @ 125
did not ensure that metadata completed before the iclog was written
was correctly on stable storage. The tail of the log moved forward,
so IO must have been completed between the two iclog writes. This
means that there is a race condition between the unconditional async
cache flush in the CIL push work and the tail LSN that is written to
the iclog. This happens like so:
CIL push work AIL push work
------------- -------------
Add to committing list
start async data dev cache flush
.....
<flush completes>
<all writes to old tail lsn are stable>
xlog_write
.... push inode create buffer
<start IO>
.....
xlog_write(commit record)
.... <IO completes>
log tail moves
xlog_assign_tail_lsn()
start_lsn == commit_lsn
<no iclog preflush!>
xlog_state_release_iclog
__xlog_state_release_iclog()
<writes *new* tail_lsn into iclog>
xlog_sync()
....
submit_bio()
<tail in log moves forward without flushing written metadata>
Essentially, this can only occur if the commit iclog is issued
without a cache flush. If the iclog bio is submitted with
REQ_PREFLUSH, then it will guarantee that all the completed IO is
one stable storage before the iclog bio with the new tail LSN in it
is written to the log.
IOWs, the tail lsn that is written to the iclog needs to be sampled
*before* we issue the cache flush that guarantees all IO up to that
LSN has been completed.
To fix this without giving up the performance advantage of the
flush/FUA optimisations (e.g. g/482 runtime halves with 5.14-rc1
compared to 5.13), we need to ensure that we always issue a cache
flush if the tail LSN changes between the initial async flush and
the commit record being written. THis requires sampling the tail_lsn
before we start the flush, and then passing the sampled tail LSN to
xlog_state_release_iclog() so it can determine if the the tail LSN
has changed while writing the checkpoint. If the tail LSN has
changed, then it needs to set the NEED_FLUSH flag on the iclog and
we'll issue another cache flush before writing the iclog.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
|
|
Fold __xlog_state_release_iclog into its only caller to prepare
make an upcoming fix easier.
Signed-off-by: Dave Chinner <[email protected]>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
|
|
The recent journal flush/FUA changes replaced the flushing of the
data device on every iclog write with an up-front async data device
cache flush. Unfortunately, the assumption of which this was based
on has been proven incorrect by the flush vs log tail update
ordering issue. As the fix for that issue uses the
XLOG_ICL_NEED_FLUSH flag to indicate that data device needs a cache
flush, we now need to (once again) ensure that an iclog write to
external logs that need a cache flush to be issued actually issue a
cache flush to the data device as well as the log device.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
|
|
We incorrectly flush the log device instead of the data device when
trying to ensure metadata is correctly on disk before writing the
unmount record.
Fixes: eef983ffeae7 ("xfs: journal IO cache flush reductions")
Signed-off-by: Dave Chinner <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>
|
|
This use-after-free happens when a fw_priv object has been freed but
hasn't been removed from the pending list (pending_fw_head). The next
time fw_load_sysfs_fallback tries to insert into the list, it ends up
accessing the pending_list member of the previously freed fw_priv.
The root cause here is that all code paths that abort the fw load
don't delete it from the pending list. For example:
_request_firmware()
-> fw_abort_batch_reqs()
-> fw_state_aborted()
To fix this, delete the fw_priv from the list in __fw_set_state() if
the new state is DONE or ABORTED. This way, all aborts will remove
the fw_priv from the list. Accordingly, remove calls to list_del_init
that were being made before calling fw_state_(aborted|done).
Also, in fw_load_sysfs_fallback, don't add the fw_priv to the pending
list if it is already aborted. Instead, just jump out and return early.
Fixes: bcfbd3523f3c ("firmware: fix a double abort case with fw_load_sysfs_fallback")
Cc: stable <[email protected]>
Reported-by: [email protected]
Tested-by: [email protected]
Reviewed-by: Shuah Khan <[email protected]>
Acked-by: Luis Chamberlain <[email protected]>
Signed-off-by: Anirudh Rayabharam <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
|
|
The only motivation for using -EAGAIN in commit 0542ad88fbdd81bb
("firmware loader: Fix _request_firmware_load() return val for fw load
abort") was to distinguish the error from -ENOMEM, and so there is no
real reason in keeping it. -EAGAIN is typically used to tell the
userspace to try something again and in this case re-using the sysfs
loading interface cannot be retried when a timeout happens, so the
return value is also bogus.
-ETIMEDOUT is received when the wait times out and returning that
is much more telling of what the reason for the failure was. So, just
propagate that instead of returning -EAGAIN.
Suggested-by: Luis Chamberlain <[email protected]>
Reviewed-by: Shuah Khan <[email protected]>
Acked-by: Luis Chamberlain <[email protected]>
Signed-off-by: Anirudh Rayabharam <[email protected]>
Cc: stable <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
|
|
Fix uart corruption issue when rx power off.
Add spin lock in mtk8250_dma_rx_complete function in APDMA mode.
when uart is used as a communication port with external device(GPS).
when external device(GPS) power off, the power of rx pin is also from
1.8v to 0v. Even if there is not any data in rx. But uart rx pin can
capture the data "0".
If uart don't receive any data in specified cycle, uart will generates
BI(Break interrupt) interrupt.
If external device(GPS) power off, we found that BI interrupt appeared
continuously and very frequently.
When uart interrupt type is BI, uart IRQ handler(8250 framwork
API:serial8250_handle_irq) will push data to tty buffer.
mtk8250_dma_rx_complete is a task of mtk_uart_apdma_rx_handler.
mtk8250_dma_rx_complete priority is lower than uart irq
handler(serial8250_handle_irq).
if we are in process of mtk8250_dma_rx_complete, uart appear BI
interrupt:1)serial8250_handle_irq will priority execution.2)it may cause
write tty buffer conflict in mtk8250_dma_rx_complete.
So the spin lock protect the rx receive data process is not break.
Signed-off-by: Zhiyong Tao <[email protected]>
Cc: stable <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
|
|
Patch e60c2991f18b make the lpuart32_get_mctrl always return 0, actually
this will break the functions of device which use flow control such as
Bluetooth.
For lpuart32 plaform, the hardware can handle the CTS automatically.
So we should set TIOCM_CTS active. Also need to set CAR and DSR active.
Patch has been tested on lpuart32 platforms such as imx8qm and imx8ulp.
Fixes: e60c2991f18b ("serial: fsl_lpuart: remove RTSCTS handling from get_mctrl()")
Cc: stable <[email protected]>
Signed-off-by: Sherry Sun <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
|
|
The Go runtime uses r30 for some special value called 'g'. It assumes
that value will remain unchanged even when calling VDSO functions.
Although r30 is non-volatile across function calls, the callee is free
to use it, as long as the callee saves the value and restores it before
returning.
It used to be true by accident that the VDSO didn't use r30, because the
VDSO was hand-written asm. When we switched to building the VDSO from C
the compiler started using r30, at least in some builds, leading to
crashes in Go. eg:
~/go/src$ ./all.bash
Building Go cmd/dist using /usr/lib/go-1.16. (go1.16.2 linux/ppc64le)
Building Go toolchain1 using /usr/lib/go-1.16.
go build os/exec: /usr/lib/go-1.16/pkg/tool/linux_ppc64le/compile: signal: segmentation fault
go build reflect: /usr/lib/go-1.16/pkg/tool/linux_ppc64le/compile: signal: segmentation fault
go tool dist: FAILED: /usr/lib/go-1.16/bin/go install -gcflags=-l -tags=math_big_pure_go compiler_bootstrap bootstrap/cmd/...: exit status 1
There are patches in flight to fix Go[1], but until they are released
and widely deployed we can workaround it in the VDSO by avoiding use of
r30.
Note this only works with GCC, clang does not support -ffixed-rN.
1: https://go-review.googlesource.com/c/go/+/328110
Fixes: ab037dd87a2f ("powerpc/vdso: Switch VDSO to generic C implementation.")
Cc: [email protected] # v5.11+
Reported-by: Paul Menzel <[email protected]>
Tested-by: Paul Menzel <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
|
|
With commit c9f3401313a5 ("powerpc: Always enable queued spinlocks for
64s, disable for others") CONFIG_PPC_QUEUED_SPINLOCKS is always
enabled on ppc64le, external modules that use spinlock APIs are
failing.
ERROR: modpost: GPL-incompatible module XXX.ko uses GPL-only symbol 'shared_processor'
Before the above commit, modules were able to build without any
issues. Also this problem is not seen on other architectures. This
problem can be workaround if CONFIG_UNINLINE_SPIN_UNLOCK is enabled in
the config. However CONFIG_UNINLINE_SPIN_UNLOCK is not enabled by
default and only enabled in certain conditions like
CONFIG_DEBUG_SPINLOCKS is set in the kernel config.
#include <linux/module.h>
spinlock_t spLock;
static int __init spinlock_test_init(void)
{
spin_lock_init(&spLock);
spin_lock(&spLock);
spin_unlock(&spLock);
return 0;
}
static void __exit spinlock_test_exit(void)
{
printk("spinlock_test unloaded\n");
}
module_init(spinlock_test_init);
module_exit(spinlock_test_exit);
MODULE_DESCRIPTION ("spinlock_test");
MODULE_LICENSE ("non-GPL");
MODULE_AUTHOR ("Srikar Dronamraju");
Given that spin locks are one of the basic facilities for module code,
this effectively makes it impossible to build/load almost any non GPL
modules on ppc64le.
This was first reported at https://github.com/openzfs/zfs/issues/11172
Currently shared_processor is exported as GPL only symbol.
Fix this for parity with other architectures by exposing
shared_processor to non-GPL modules too.
Fixes: 14c73bd344da ("powerpc/vcpu: Assume dedicated processors as non-preempt")
Cc: [email protected] # v5.5+
Reported-by: [email protected]
Signed-off-by: Srikar Dronamraju <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
|
|
The chip supports high transfer rates, but with the small default buffers
(64 bytes read), some entire blocks are regularly lost. This typically
happens at 1.5 Mbps (which is the default speed on Rockchip devices) when
used as a console to access U-Boot where the output of the "help" command
misses many lines and where "printenv" mangles the environment.
The FTDI driver doesn't suffer at all from this. One difference is that
it uses 512 bytes rx buffers and 256 bytes tx buffers. Adopting these
values completely resolved the issue, even the output of "dmesg" is
reliable. I preferred to leave the Tx value unchanged as it is not
involved in this issue, while a change could increase the risk of
triggering the same issue with other devices having too small buffers.
I verified that it backports well (and works) at least to 5.4. It's of
low importance enough to be dropped where it doesn't trivially apply
anymore.
Cc: [email protected]
Signed-off-by: Willy Tarreau <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Johan Hovold <[email protected]>
|
|
Building with -Warray-bounds on systems with 64K pages there's a
warning:
fs/btrfs/disk-io.c: In function ‘csum_tree_block’:
fs/btrfs/disk-io.c:226:34: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds]
226 | kaddr = page_address(buf->pages[i]);
| ~~~~~~~~~~^~~
./include/linux/mm.h:1630:48: note: in definition of macro ‘page_address’
1630 | #define page_address(page) lowmem_page_address(page)
| ^~~~
In file included from fs/btrfs/ctree.h:32,
from fs/btrfs/disk-io.c:23:
fs/btrfs/extent_io.h:98:15: note: while referencing ‘pages’
98 | struct page *pages[1];
| ^~~~~
The compiler has no way to know that in that case the nodesize is exactly
PAGE_SIZE, so the resulting number of pages will be correct (1).
Let's use num_extent_pages that makes the case nodesize == PAGE_SIZE
explicitly 1.
Reported-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>
|
|
This commit fixes a functional regression introduced by the commit 82f09a637dd3
("HID: ft260: improve error handling of ft260_hid_feature_report_get()")
when upon USB disconnect, the FTDI FT260 i2c device is still available within
the /dev folder.
In my company's product, where the host USB to FT260 USB connection is
hard-wired in the PCB, the issue is not reproducible. To reproduce it, I used
the VirtualBox Ubuntu 20.04 VM and the UMFT260EV1A development module for the
FTDI FT260 chip:
Plug the UMFT260EV1A module into a USB port and attach it to VM.
The VM shows 2 i2c devices under the /dev:
michael@michael-VirtualBox:~$ ls /dev/i2c-*
/dev/i2c-0 /dev/i2c-1
The i2c-0 is not related to the FTDI FT260:
michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-0/name
SMBus PIIX4 adapter at 4100
The i2c-1 is created by hid-ft260.ko:
michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-1/name
FT260 usb-i2c bridge on hidraw1
Now, detach the FTDI FT260 USB device from VM. We expect the /dev/i2c-1
to disappear, but it's still here:
michael@michael-VirtualBox:~$ ls /dev/i2c-*
/dev/i2c-0 /dev/i2c-1
And the kernel log shows:
[ +0.001202] usb 2-2: USB disconnect, device number 3
[ +0.000109] ft260 0003:0403:6030.0002: failed to retrieve system status
[ +0.000316] ft260 0003:0403:6030.0003: failed to retrieve system status
It happens because the commit 82f09a637dd3 changed the ft260_get_system_config()
return logic. This caused the ft260_is_interface_enabled() to exit with error
upon the FT260 device USB disconnect, which in turn, aborted the ft260_remove()
before deleting the FT260 i2c device and cleaning its sysfs stuff.
This commit restores the FT260 USB removal functionality and improves the
ft260_is_interface_enabled() code to handle correctly all chip modes defined
by the device interface configuration pins DCNF0 and DCNF1.
Signed-off-by: Michael Zaidman <[email protected]>
Acked-by: Aaron Jones (FTDI-UK) <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
|
|
The Acer Swift SF314-42 laptop is using Realtek ALC255 codec. Add a
quirk so microphone in a headset connected via the right-hand side jack
is usable.
Signed-off-by: Alexander Monakov <[email protected]>
Cc: <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>
|
|
https://gitlab.freedesktop.org/agd5f/linux into drm-fixes
amd-drm-fixes-5.14-2021-07-28:
amdgpu:
- Fix resource leak in an error path
- Avoid stack contents exposure in error path
- pmops check fix for S0ix vs S3
- DCN 2.1 display fixes
- DCN 2.0 display fix
- Backlight control fix for laptops with HDR panels
- Maintainers updates
Signed-off-by: Dave Airlie <[email protected]>
From: Alex Deucher <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb into usb-linus
Peter writes:
Several small bug-fixes for cdns3 and cdnsp driver
* tag 'usb-v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb:
usb: cdnsp: Fix the IMAN_IE_SET and IMAN_IE_CLEAR macro
usb: cdnsp: Fixed issue with ZLP
usb: cdnsp: Fix incorrect supported maximum speed
usb: cdns3: Fixed incorrect gadget state
|
|
IMAN_IE is BIT(1), so these macro are respectively equivalent to BIT(1)
and 0, whatever the value of 'p'.
The purpose was to set and reset a single bit in 'p'.
Fix these macros to do that correctly.
Acked-by: Pawel Laszczak <[email protected]>
Fixes: e93e58d27402 ("usb: cdnsp: Device side header file for CDNSP driver")
Signed-off-by: Christophe JAILLET <[email protected]>
Link: https://lore.kernel.org/r/d12bfcc9cbffb89e27b120668821b3c4f09b6755.1624390584.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Peter Chen <[email protected]>
|
|
The condition "if (need_zero_pkt && zero_len_trb)" was always false
and it caused that TRB for ZLP was not prepared.
Fix causes that after preparing last TRB in TD, the driver prepares
additional TD with ZLP when a ZLP is required.
Cc: <[email protected]>
Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Signed-off-by: Pawel Laszczak <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Peter Chen <[email protected]>
|
|
Driver had hardcoded in initialization maximum supported speed
to USB_SPEED_SUPER_PLUS but it should consider the speed
returned from usb_get_maximum_speed function.
Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Signed-off-by: Pawel Laszczak <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Peter Chen <[email protected]>
|
|
For delayed status phase, the usb_gadget->state was set
to USB_STATE_ADDRESS and it has never been updated to
USB_STATE_CONFIGURED.
Patch updates the gadget state to correct USB_STATE_CONFIGURED.
As a result of this bug the controller was not able to enter to
Test Mode while using MSC function.
Cc: <[email protected]>
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: Pawel Laszczak <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Peter Chen <[email protected]>
|
|
The memory reserved by console/PALcode or non-volatile memory is not added
to memblock.memory.
Since commit fa3354e4ea39 (mm: free_area_init: use maximal zone PFNs rather
than zone sizes) the initialization of the memory map relies on the
accuracy of memblock.memory to properly calculate zone sizes. The holes in
memblock.memory caused by absent regions reserved by the firmware cause
incorrect initialization of struct pages which leads to BUG() during the
initial page freeing:
BUG: Bad page state in process swapper pfn:2ffc53
page:fffffc000ecf14c0 refcount:0 mapcount:1 mapping:0000000000000000 index:0x0
flags: 0x0()
raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-03841-gfa3354e4ea39-dirty #26
fffffc0001b5bd68 fffffc0001b5be80 fffffc00011cd148 fffffc000ecf14c0
fffffc00019803df fffffc0001b5be80 fffffc00011ce340 fffffc000ecf14c0
0000000000000000 fffffc0001b5be80 fffffc0001b482c0 fffffc00027d6618
fffffc00027da7d0 00000000002ff97a 0000000000000000 fffffc0001b5be80
fffffc00011d1abc fffffc000ecf14c0 fffffc0002d00000 fffffc0001b5be80
fffffc0001b2350c 0000000000300000 fffffc0001b48298 fffffc0001b482c0
Trace:
[<fffffc00011cd148>] bad_page+0x168/0x1b0
[<fffffc00011ce340>] free_pcp_prepare+0x1e0/0x290
[<fffffc00011d1abc>] free_unref_page+0x2c/0xa0
[<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30
[<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30
[<fffffc000101001c>] _stext+0x1c/0x20
Fix this by registering the reserved ranges in memblock.memory.
Link: https://lore.kernel.org/lkml/20210726192311.uffqnanxw3ac5wwi@ivybridge
Fixes: fa3354e4ea39 ("mm: free_area_init: use maximal zone PFNs rather than zone sizes")
Reported-by: Matt Turner <[email protected]>
Cc: <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Signed-off-by: Matt Turner <[email protected]>
|
|
The list_for_each_entry() iterator, "adapter" in this code, can never be
NULL. If we exit the loop without finding the correct adapter then
"adapter" points invalid memory that is an offset from the list head. This
will eventually lead to memory corruption and presumably a kernel crash.
Link: https://lore.kernel.org/r/[email protected]
Acked-by: Sumit Saxena <[email protected]>
Signed-off-by: Harshvardhan Jha <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
|
|
The TMF timeout timer may trigger at the same time when the response from a
controller is being handled. When this happens the SAS task may get freed
before the response processing is finished.
Fix this by calling complete() only when SAS_TASK_STATE_DONE is not set.
A similar race condition was fixed in commit b90cd6f2b905 ("scsi: libsas:
fix a race condition when smp task timeout")
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Vishakha Channapattan <[email protected]>
Acked-by: Jack Wang <[email protected]>
Signed-off-by: Igor Pylypiv <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
|
|
git://anongit.freedesktop.org/drm/drm-intel into drm-fixes
Display related fixes:
- Fix vbt port mask
- Fix around reading the right DSC disable fuse in display_ver 10
- Split display version 9 and 10 in intel_setup_outputs
Signed-off-by: Dave Airlie <[email protected]>
From: Rodrigo Vivi <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
|
|
git://anongit.freedesktop.org/drm/drm-misc into drm-fixes
Short summary of fixes pull:
* panel: Fix bpc for ytc700tlag_05_201c
* ttm: debugfs init fixes
Signed-off-by: Dave Airlie <[email protected]>
From: Thomas Zimmermann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
|
|
https://gitlab.freedesktop.org/drm/msm into drm-fixes
A few fixes for v5.14, including a fix for a crash if display triggers
an iommu fault (which tends to happen at probe time on devices with
bootloader fw that leaves display enabled as kernel starts)
Signed-off-by: Dave Airlie <[email protected]>
From: Rob Clark <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/CAF6AEGubeV_uzWhsqp_+EmQmPcPatnqWOQnARoing2YvQOHbyg@mail.gmail.com
|
|
Daniel Borkmann says:
====================
pull-request: bpf 2021-07-29
The following pull-request contains BPF updates for your *net* tree.
We've added 9 non-merge commits during the last 14 day(s) which contain
a total of 20 files changed, 446 insertions(+), 138 deletions(-).
The main changes are:
1) Fix UBSAN out-of-bounds splat for showing XDP link fdinfo, from Lorenz Bauer.
2) Fix insufficient Spectre v4 mitigation in BPF runtime, from Daniel Borkmann,
Piotr Krysiuk and Benedict Schlueter.
3) Batch of fixes for BPF sockmap found under stress testing, from John Fastabend.
====================
Signed-off-by: David S. Miller <[email protected]>
|
|
Spectre v4 gadgets make use of memory disambiguation, which is a set of
techniques that execute memory access instructions, that is, loads and
stores, out of program order; Intel's optimization manual, section 2.4.4.5:
A load instruction micro-op may depend on a preceding store. Many
microarchitectures block loads until all preceding store addresses are
known. The memory disambiguator predicts which loads will not depend on
any previous stores. When the disambiguator predicts that a load does
not have such a dependency, the load takes its data from the L1 data
cache. Eventually, the prediction is verified. If an actual conflict is
detected, the load and all succeeding instructions are re-executed.
af86ca4e3088 ("bpf: Prevent memory disambiguation attack") tried to mitigate
this attack by sanitizing the memory locations through preemptive "fast"
(low latency) stores of zero prior to the actual "slow" (high latency) store
of a pointer value such that upon dependency misprediction the CPU then
speculatively executes the load of the pointer value and retrieves the zero
value instead of the attacker controlled scalar value previously stored at
that location, meaning, subsequent access in the speculative domain is then
redirected to the "zero page".
The sanitized preemptive store of zero prior to the actual "slow" store is
done through a simple ST instruction based on r10 (frame pointer) with
relative offset to the stack location that the verifier has been tracking
on the original used register for STX, which does not have to be r10. Thus,
there are no memory dependencies for this store, since it's only using r10
and immediate constant of zero; hence af86ca4e3088 /assumed/ a low latency
operation.
However, a recent attack demonstrated that this mitigation is not sufficient
since the preemptive store of zero could also be turned into a "slow" store
and is thus bypassed as well:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
31: (7b) *(u64 *)(r10 -16) = r2
// r9 will remain "fast" register, r10 will become "slow" register below
32: (bf) r9 = r10
// JIT maps BPF reg to x86 reg:
// r9 -> r15 (callee saved)
// r10 -> rbp
// train store forward prediction to break dependency link between both r9
// and r10 by evicting them from the predictor's LRU table.
33: (61) r0 = *(u32 *)(r7 +24576)
34: (63) *(u32 *)(r7 +29696) = r0
35: (61) r0 = *(u32 *)(r7 +24580)
36: (63) *(u32 *)(r7 +29700) = r0
37: (61) r0 = *(u32 *)(r7 +24584)
38: (63) *(u32 *)(r7 +29704) = r0
39: (61) r0 = *(u32 *)(r7 +24588)
40: (63) *(u32 *)(r7 +29708) = r0
[...]
543: (61) r0 = *(u32 *)(r7 +25596)
544: (63) *(u32 *)(r7 +30716) = r0
// prepare call to bpf_ringbuf_output() helper. the latter will cause rbp
// to spill to stack memory while r13/r14/r15 (all callee saved regs) remain
// in hardware registers. rbp becomes slow due to push/pop latency. below is
// disasm of bpf_ringbuf_output() helper for better visual context:
//
// ffffffff8117ee20: 41 54 push r12
// ffffffff8117ee22: 55 push rbp
// ffffffff8117ee23: 53 push rbx
// ffffffff8117ee24: 48 f7 c1 fc ff ff ff test rcx,0xfffffffffffffffc
// ffffffff8117ee2b: 0f 85 af 00 00 00 jne ffffffff8117eee0 <-- jump taken
// [...]
// ffffffff8117eee0: 49 c7 c4 ea ff ff ff mov r12,0xffffffffffffffea
// ffffffff8117eee7: 5b pop rbx
// ffffffff8117eee8: 5d pop rbp
// ffffffff8117eee9: 4c 89 e0 mov rax,r12
// ffffffff8117eeec: 41 5c pop r12
// ffffffff8117eeee: c3 ret
545: (18) r1 = map[id:4]
547: (bf) r2 = r7
548: (b7) r3 = 0
549: (b7) r4 = 4
550: (85) call bpf_ringbuf_output#194288
// instruction 551 inserted by verifier \
551: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
// storing map value pointer r7 at fp-16 | since value of r10 is "slow".
552: (7b) *(u64 *)(r10 -16) = r7 /
// following "fast" read to the same memory location, but due to dependency
// misprediction it will speculatively execute before insn 551/552 completes.
553: (79) r2 = *(u64 *)(r9 -16)
// in speculative domain contains attacker controlled r2. in non-speculative
// domain this contains r7, and thus accesses r7 +0 below.
554: (71) r3 = *(u8 *)(r2 +0)
// leak r3
As can be seen, the current speculative store bypass mitigation which the
verifier inserts at line 551 is insufficient since /both/, the write of
the zero sanitation as well as the map value pointer are a high latency
instruction due to prior memory access via push/pop of r10 (rbp) in contrast
to the low latency read in line 553 as r9 (r15) which stays in hardware
registers. Thus, architecturally, fp-16 is r7, however, microarchitecturally,
fp-16 can still be r2.
Initial thoughts to address this issue was to track spilled pointer loads
from stack and enforce their load via LDX through r10 as well so that /both/
the preemptive store of zero /as well as/ the load use the /same/ register
such that a dependency is created between the store and load. However, this
option is not sufficient either since it can be bypassed as well under
speculation. An updated attack with pointer spill/fills now _all_ based on
r10 would look as follows:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
[...]
// longer store forward prediction training sequence than before.
2062: (61) r0 = *(u32 *)(r7 +25588)
2063: (63) *(u32 *)(r7 +30708) = r0
2064: (61) r0 = *(u32 *)(r7 +25592)
2065: (63) *(u32 *)(r7 +30712) = r0
2066: (61) r0 = *(u32 *)(r7 +25596)
2067: (63) *(u32 *)(r7 +30716) = r0
// store the speculative load address (scalar) this time after the store
// forward prediction training.
2068: (7b) *(u64 *)(r10 -16) = r2
// preoccupy the CPU store port by running sequence of dummy stores.
2069: (63) *(u32 *)(r7 +29696) = r0
2070: (63) *(u32 *)(r7 +29700) = r0
2071: (63) *(u32 *)(r7 +29704) = r0
2072: (63) *(u32 *)(r7 +29708) = r0
2073: (63) *(u32 *)(r7 +29712) = r0
2074: (63) *(u32 *)(r7 +29716) = r0
2075: (63) *(u32 *)(r7 +29720) = r0
2076: (63) *(u32 *)(r7 +29724) = r0
2077: (63) *(u32 *)(r7 +29728) = r0
2078: (63) *(u32 *)(r7 +29732) = r0
2079: (63) *(u32 *)(r7 +29736) = r0
2080: (63) *(u32 *)(r7 +29740) = r0
2081: (63) *(u32 *)(r7 +29744) = r0
2082: (63) *(u32 *)(r7 +29748) = r0
2083: (63) *(u32 *)(r7 +29752) = r0
2084: (63) *(u32 *)(r7 +29756) = r0
2085: (63) *(u32 *)(r7 +29760) = r0
2086: (63) *(u32 *)(r7 +29764) = r0
2087: (63) *(u32 *)(r7 +29768) = r0
2088: (63) *(u32 *)(r7 +29772) = r0
2089: (63) *(u32 *)(r7 +29776) = r0
2090: (63) *(u32 *)(r7 +29780) = r0
2091: (63) *(u32 *)(r7 +29784) = r0
2092: (63) *(u32 *)(r7 +29788) = r0
2093: (63) *(u32 *)(r7 +29792) = r0
2094: (63) *(u32 *)(r7 +29796) = r0
2095: (63) *(u32 *)(r7 +29800) = r0
2096: (63) *(u32 *)(r7 +29804) = r0
2097: (63) *(u32 *)(r7 +29808) = r0
2098: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; same as before, also including the
// sanitation store with 0 from the current mitigation by the verifier.
2099: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
2100: (7b) *(u64 *)(r10 -16) = r7 | since store unit is still busy.
// load from stack intended to bypass stores.
2101: (79) r2 = *(u64 *)(r10 -16)
2102: (71) r3 = *(u8 *)(r2 +0)
// leak r3
[...]
Looking at the CPU microarchitecture, the scheduler might issue loads (such
as seen in line 2101) before stores (line 2099,2100) because the load execution
units become available while the store execution unit is still busy with the
sequence of dummy stores (line 2069-2098). And so the load may use the prior
stored scalar from r2 at address r10 -16 for speculation. The updated attack
may work less reliable on CPU microarchitectures where loads and stores share
execution resources.
This concludes that the sanitizing with zero stores from af86ca4e3088 ("bpf:
Prevent memory disambiguation attack") is insufficient. Moreover, the detection
of stack reuse from af86ca4e3088 where previously data (STACK_MISC) has been
written to a given stack slot where a pointer value is now to be stored does
not have sufficient coverage as precondition for the mitigation either; for
several reasons outlined as follows:
1) Stack content from prior program runs could still be preserved and is
therefore not "random", best example is to split a speculative store
bypass attack between tail calls, program A would prepare and store the
oob address at a given stack slot and then tail call into program B which
does the "slow" store of a pointer to the stack with subsequent "fast"
read. From program B PoV such stack slot type is STACK_INVALID, and
therefore also must be subject to mitigation.
2) The STACK_SPILL must not be coupled to register_is_const(&stack->spilled_ptr)
condition, for example, the previous content of that memory location could
also be a pointer to map or map value. Without the fix, a speculative
store bypass is not mitigated in such precondition and can then lead to
a type confusion in the speculative domain leaking kernel memory near
these pointer types.
While brainstorming on various alternative mitigation possibilities, we also
stumbled upon a retrospective from Chrome developers [0]:
[...] For variant 4, we implemented a mitigation to zero the unused memory
of the heap prior to allocation, which cost about 1% when done concurrently
and 4% for scavenging. Variant 4 defeats everything we could think of. We
explored more mitigations for variant 4 but the threat proved to be more
pervasive and dangerous than we anticipated. For example, stack slots used
by the register allocator in the optimizing compiler could be subject to
type confusion, leading to pointer crafting. Mitigating type confusion for
stack slots alone would have required a complete redesign of the backend of
the optimizing compiler, perhaps man years of work, without a guarantee of
completeness. [...]
From BPF side, the problem space is reduced, however, options are rather
limited. One idea that has been explored was to xor-obfuscate pointer spills
to the BPF stack:
[...]
// preoccupy the CPU store port by running sequence of dummy stores.
[...]
2106: (63) *(u32 *)(r7 +29796) = r0
2107: (63) *(u32 *)(r7 +29800) = r0
2108: (63) *(u32 *)(r7 +29804) = r0
2109: (63) *(u32 *)(r7 +29808) = r0
2110: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; xored with random 'secret' value
// of 943576462 before store ...
2111: (b4) w11 = 943576462
2112: (af) r11 ^= r7
2113: (7b) *(u64 *)(r10 -16) = r11
2114: (79) r11 = *(u64 *)(r10 -16)
2115: (b4) w2 = 943576462
2116: (af) r2 ^= r11
// ... and restored with the same 'secret' value with the help of AX reg.
2117: (71) r3 = *(u8 *)(r2 +0)
[...]
While the above would not prevent speculation, it would make data leakage
infeasible by directing it to random locations. In order to be effective
and prevent type confusion under speculation, such random secret would have
to be regenerated for each store. The additional complexity involved for a
tracking mechanism that prevents jumps such that restoring spilled pointers
would not get corrupted is not worth the gain for unprivileged. Hence, the
fix in here eventually opted for emitting a non-public BPF_ST | BPF_NOSPEC
instruction which the x86 JIT translates into a lfence opcode. Inserting the
latter in between the store and load instruction is one of the mitigations
options [1]. The x86 instruction manual notes:
[...] An LFENCE that follows an instruction that stores to memory might
complete before the data being stored have become globally visible. [...]
The latter meaning that the preceding store instruction finished execution
and the store is at minimum guaranteed to be in the CPU's store queue, but
it's not guaranteed to be in that CPU's L1 cache at that point (globally
visible). The latter would only be guaranteed via sfence. So the load which
is guaranteed to execute after the lfence for that local CPU would have to
rely on store-to-load forwarding. [2], in section 2.3 on store buffers says:
[...] For every store operation that is added to the ROB, an entry is
allocated in the store buffer. This entry requires both the virtual and
physical address of the target. Only if there is no free entry in the store
buffer, the frontend stalls until there is an empty slot available in the
store buffer again. Otherwise, the CPU can immediately continue adding
subsequent instructions to the ROB and execute them out of order. On Intel
CPUs, the store buffer has up to 56 entries. [...]
One small upside on the fix is that it lifts constraints from af86ca4e3088
where the sanitize_stack_off relative to r10 must be the same when coming
from different paths. The BPF_ST | BPF_NOSPEC gets emitted after a BPF_STX
or BPF_ST instruction. This happens either when we store a pointer or data
value to the BPF stack for the first time, or upon later pointer spills.
The former needs to be enforced since otherwise stale stack data could be
leaked under speculation as outlined earlier. For non-x86 JITs the BPF_ST |
BPF_NOSPEC mapping is currently optimized away, but others could emit a
speculation barrier as well if necessary. For real-world unprivileged
programs e.g. generated by LLVM, pointer spill/fill is only generated upon
register pressure and LLVM only tries to do that for pointers which are not
used often. The program main impact will be the initial BPF_ST | BPF_NOSPEC
sanitation for the STACK_INVALID case when the first write to a stack slot
occurs e.g. upon map lookup. In future we might refine ways to mitigate
the latter cost.
[0] https://arxiv.org/pdf/1902.05178.pdf
[1] https://msrc-blog.microsoft.com/2018/05/21/analysis-and-mitigation-of-speculative-store-bypass-cve-2018-3639/
[2] https://arxiv.org/pdf/1905.05725.pdf
Fixes: af86ca4e3088 ("bpf: Prevent memory disambiguation attack")
Fixes: f7cf25b2026d ("bpf: track spill/fill of constants")
Co-developed-by: Piotr Krysiuk <[email protected]>
Co-developed-by: Benedict Schlueter <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Piotr Krysiuk <[email protected]>
Signed-off-by: Benedict Schlueter <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
|
|
In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.
This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.
The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.
Co-developed-by: Piotr Krysiuk <[email protected]>
Co-developed-by: Benedict Schlueter <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Piotr Krysiuk <[email protected]>
Signed-off-by: Benedict Schlueter <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
|
|
We lost parsing of backupuid in the switch to new mount API.
Add it back.
Signed-off-by: Ronnie Sahlberg <[email protected]>
Reviewed-by: Shyam Prasad N <[email protected]>
Cc: <[email protected]> # v5.11+
Reported-by: Xiaoli Feng <[email protected]>
Signed-off-by: Steve French <[email protected]>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull ext2 and reiserfs fixes from Jan Kara:
"A fix for the ext2 conversion to kmap_local() and two reiserfs
hardening fixes"
* tag 'fixes_for_v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
reiserfs: check directory items on read from disk
fs/ext2: Avoid page_address on pages returned by ext2_get_page
reiserfs: add check for root_inode in reiserfs_fill_super
|
|
The race happens because put_ucounts() doesn't use spinlock and
get_ucounts is not under spinlock:
CPU0 CPU1
---- ----
alloc_ucounts() put_ucounts()
spin_lock_irq(&ucounts_lock);
ucounts = find_ucounts(ns, uid, hashent);
atomic_dec_and_test(&ucounts->count))
spin_unlock_irq(&ucounts_lock);
spin_lock_irqsave(&ucounts_lock, flags);
hlist_del_init(&ucounts->node);
spin_unlock_irqrestore(&ucounts_lock, flags);
kfree(ucounts);
ucounts = get_ucounts(ucounts);
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_add_negative include/asm-generic/atomic-instrumented.h:556 [inline]
BUG: KASAN: use-after-free in get_ucounts kernel/ucount.c:152 [inline]
BUG: KASAN: use-after-free in get_ucounts kernel/ucount.c:150 [inline]
BUG: KASAN: use-after-free in alloc_ucounts+0x19b/0x5b0 kernel/ucount.c:188
Write of size 4 at addr ffff88802821e41c by task syz-executor.4/16785
CPU: 1 PID: 16785 Comm: syz-executor.4 Not tainted 5.14.0-rc1-next-20210712-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_add_negative include/asm-generic/atomic-instrumented.h:556 [inline]
get_ucounts kernel/ucount.c:152 [inline]
get_ucounts kernel/ucount.c:150 [inline]
alloc_ucounts+0x19b/0x5b0 kernel/ucount.c:188
set_cred_ucounts+0x171/0x3a0 kernel/cred.c:684
__sys_setuid+0x285/0x400 kernel/sys.c:623
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fde54097188 EFLAGS: 00000246 ORIG_RAX: 0000000000000069
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000000ff
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc8655740f R14: 00007fde54097300 R15: 0000000000022000
Allocated by task 16784:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
____kasan_kmalloc mm/kasan/common.c:472 [inline]
__kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
alloc_ucounts+0x23d/0x5b0 kernel/ucount.c:169
set_cred_ucounts+0x171/0x3a0 kernel/cred.c:684
__sys_setuid+0x285/0x400 kernel/sys.c:623
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 16785:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:229 [inline]
slab_free_hook mm/slub.c:1650 [inline]
slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1675
slab_free mm/slub.c:3235 [inline]
kfree+0xeb/0x650 mm/slub.c:4295
put_ucounts kernel/ucount.c:200 [inline]
put_ucounts+0x117/0x150 kernel/ucount.c:192
put_cred_rcu+0x27a/0x520 kernel/cred.c:124
rcu_do_batch kernel/rcu/tree.c:2550 [inline]
rcu_core+0x7ab/0x1380 kernel/rcu/tree.c:2785
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
Last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:348
insert_work+0x48/0x370 kernel/workqueue.c:1332
__queue_work+0x5c1/0xed0 kernel/workqueue.c:1498
queue_work_on+0xee/0x110 kernel/workqueue.c:1525
queue_work include/linux/workqueue.h:507 [inline]
call_usermodehelper_exec+0x1f0/0x4c0 kernel/umh.c:435
kobject_uevent_env+0xf8f/0x1650 lib/kobject_uevent.c:618
netdev_queue_add_kobject net/core/net-sysfs.c:1621 [inline]
netdev_queue_update_kobjects+0x374/0x450 net/core/net-sysfs.c:1655
register_queue_kobjects net/core/net-sysfs.c:1716 [inline]
netdev_register_kobject+0x35a/0x430 net/core/net-sysfs.c:1959
register_netdevice+0xd33/0x1500 net/core/dev.c:10331
nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline]
nsim_create+0x381/0x4d0 drivers/net/netdevsim/netdev.c:364
__nsim_dev_port_add+0x32e/0x830 drivers/net/netdevsim/dev.c:1295
nsim_dev_port_add_all+0x53/0x150 drivers/net/netdevsim/dev.c:1355
nsim_dev_probe+0xcb5/0x1190 drivers/net/netdevsim/dev.c:1496
call_driver_probe drivers/base/dd.c:517 [inline]
really_probe+0x23c/0xcd0 drivers/base/dd.c:595
__driver_probe_device+0x338/0x4d0 drivers/base/dd.c:747
driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:777
__device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:894
bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
__device_attach+0x228/0x4a0 drivers/base/dd.c:965
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
device_add+0xc2f/0x2180 drivers/base/core.c:3356
nsim_bus_dev_new drivers/net/netdevsim/bus.c:431 [inline]
new_device_store+0x436/0x710 drivers/net/netdevsim/bus.c:298
bus_attr_store+0x72/0xa0 drivers/base/bus.c:122
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139
kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2152 [inline]
new_sync_write+0x426/0x650 fs/read_write.c:518
vfs_write+0x75a/0xa40 fs/read_write.c:605
ksys_write+0x12d/0x250 fs/read_write.c:658
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Second to last potentially related work creation:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:348
insert_work+0x48/0x370 kernel/workqueue.c:1332
__queue_work+0x5c1/0xed0 kernel/workqueue.c:1498
queue_work_on+0xee/0x110 kernel/workqueue.c:1525
queue_work include/linux/workqueue.h:507 [inline]
call_usermodehelper_exec+0x1f0/0x4c0 kernel/umh.c:435
kobject_uevent_env+0xf8f/0x1650 lib/kobject_uevent.c:618
kobject_synth_uevent+0x701/0x850 lib/kobject_uevent.c:208
uevent_store+0x20/0x50 drivers/base/core.c:2371
dev_attr_store+0x50/0x80 drivers/base/core.c:2072
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139
kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2152 [inline]
new_sync_write+0x426/0x650 fs/read_write.c:518
vfs_write+0x75a/0xa40 fs/read_write.c:605
ksys_write+0x12d/0x250 fs/read_write.c:658
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
The buggy address belongs to the object at ffff88802821e400
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 28 bytes inside of
192-byte region [ffff88802821e400, ffff88802821e4c0)
The buggy address belongs to the page:
page:ffffea0000a08780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2821e
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 dead000000000100 dead000000000122 ffff888010841a00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 12874702440, free_ts 12637793385
prep_new_page mm/page_alloc.c:2433 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4166
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5374
alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2119
alloc_pages+0x238/0x2a0 mm/mempolicy.c:2242
alloc_slab_page mm/slub.c:1713 [inline]
allocate_slab+0x32b/0x4c0 mm/slub.c:1853
new_slab mm/slub.c:1916 [inline]
new_slab_objects mm/slub.c:2662 [inline]
___slab_alloc+0x4ba/0x820 mm/slub.c:2825
__slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2865
slab_alloc_node mm/slub.c:2947 [inline]
slab_alloc mm/slub.c:2989 [inline]
__kmalloc+0x312/0x330 mm/slub.c:4133
kmalloc include/linux/slab.h:596 [inline]
kzalloc include/linux/slab.h:721 [inline]
__register_sysctl_table+0x112/0x1090 fs/proc/proc_sysctl.c:1318
rds_tcp_init_net+0x1db/0x4f0 net/rds/tcp.c:551
ops_init+0xaf/0x470 net/core/net_namespace.c:140
__register_pernet_operations net/core/net_namespace.c:1137 [inline]
register_pernet_operations+0x35a/0x850 net/core/net_namespace.c:1214
register_pernet_device+0x26/0x70 net/core/net_namespace.c:1301
rds_tcp_init+0x77/0xe0 net/rds/tcp.c:717
do_one_initcall+0x103/0x650 init/main.c:1285
do_initcall_level init/main.c:1360 [inline]
do_initcalls init/main.c:1376 [inline]
do_basic_setup init/main.c:1396 [inline]
kernel_init_freeable+0x6b8/0x741 init/main.c:1598
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1343 [inline]
free_pcp_prepare+0x312/0x7d0 mm/page_alloc.c:1394
free_unref_page_prepare mm/page_alloc.c:3329 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3408
__vunmap+0x783/0xb70 mm/vmalloc.c:2587
free_work+0x58/0x70 mm/vmalloc.c:82
process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Memory state around the buggy address:
ffff88802821e300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88802821e380: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
>ffff88802821e400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802821e480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff88802821e500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
- The race fix has two parts.
* Changing the code to guarantee that ucounts->count is only decremented
when ucounts_lock is held. This guarantees that find_ucounts
will never find a structure with a zero reference count.
* Changing alloc_ucounts to increment ucounts->count while
ucounts_lock is held. This guarantees the reference count on the
found data structure will not be decremented to zero (and the data
structure freed) before the reference count is incremented.
-- Eric Biederman
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Fixes: b6c336528926 ("Use atomic_t for ucounts reference counting")
Cc: Hillf Danton <[email protected]>
Signed-off-by: Alexey Gladkov <[email protected]>
Link: https://lkml.kernel.org/r/7b2ace1759b281cdd2d66101d6b305deef722efb.1627397820.git.legion@kernel.org
Signed-off-by: Eric W. Biederman <[email protected]>
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