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2018-02-27gpiolib: Keep returning EPROBE_DEFER when we shouldMaxime Ripard1-0/+13
Commits c85823390215 ("gpio: of: Support SPI nonstandard GPIO properties") and 6a537d48461d ("gpio: of: Support regulator nonstandard GPIO properties") have introduced a regression in the way error codes from of_get_named_gpiod_flags are handled. Previously, those errors codes were returned immediately, but the two commits mentioned above are now overwriting the error pointer, meaning that whatever value has been returned will be dropped in favor of whatever the two new functions will return. This might not be a big deal except for EPROBE_DEFER, on which GPIOlib customers will depend on, and that will now be returned as an hard error which means that they will not probe anymore, instead of gently deferring their probe. Since EPROBE_DEFER basically means that we have found a valid property but there was no GPIO controller registered to handle it, fix this issues by returning it as soon as we encounter it. Fixes: c85823390215 ("gpio: of: Support SPI nonstandard GPIO properties") Fixes: 6a537d48461d ("gpio: of: Support regulator nonstandard GPIO properties") Signed-off-by: Maxime Ripard <[email protected]> [Fold in fix to the fix] Signed-off-by: Linus Walleij <[email protected]>
2018-02-27virtio-gpu: fix ioctl and expose the fixed status to userspace.Dave Airlie2-6/+12
This exposes to mesa that it can use the fixed ioctl for querying later cap sets, cap set 1 is forever frozen in time. Signed-off-by: Dave Airlie <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected] Signed-off-by: Gerd Hoffmann <[email protected]>
2018-02-27netfilter: nf_tables: missing attribute validation in nf_tables_delflowtable()Pablo Neira Ayuso1-0/+5
Return -EINVAL is mandatory attributes are missing. Signed-off-by: Pablo Neira Ayuso <[email protected]>
2018-02-27netfilter: nf_tables: return EBUSY if device already belongs to flowtablePablo Neira Ayuso1-1/+17
If the netdevice is already part of a flowtable, return EBUSY. I cannot find a valid usecase for having two flowtables bound to the same netdevice. We can still have two flowtable where the device set is disjoint. Signed-off-by: Pablo Neira Ayuso <[email protected]>
2018-02-26bpf, ppc64: fix out of bounds access in tail callDaniel Borkmann1-0/+1
While working on 16338a9b3ac3 ("bpf, arm64: fix out of bounds access in tail call") I noticed that ppc64 JIT is partially affected as well. While the bound checking is correctly performed as unsigned comparison, the register with the index value however, is never truncated into 32 bit space, so e.g. a index value of 0x100000000ULL with a map of 1 element would pass with PPC_CMPLW() whereas we later on continue with the full 64 bit register value. Therefore, as we do in interpreter and other JITs truncate the value to 32 bit initially in order to fix access. Fixes: ce0761419fae ("powerpc/bpf: Implement support for tail calls") Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: Naveen N. Rao <[email protected]> Tested-by: Naveen N. Rao <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
2018-02-26r8152: fix tx packets accountingEric Dumazet1-1/+1
r8152 driver handles TSO packets (limited to ~16KB) quite well, but pretends each TSO logical packet is a single packet on the wire. There is also some error since headers are accounted once, but error rate is small enough that we do not care. Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26tpm: fix potential buffer overruns caused by bit glitches on the busJeremy Boone2-0/+8
Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. If a bit does flip it could cause an overrun if it's in one of the size parameters, so sanity check that we're not overrunning the provided buffer when doing a memcpy(). Signed-off-by: Jeremy Boone <[email protected]> Cc: [email protected] Signed-off-by: James Bottomley <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Tested-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> Signed-off-by: James Morris <[email protected]>
2018-02-26tpm: st33zp24: fix potential buffer overruns caused by bit glitches on the busJeremy Boone1-2/+2
Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. In all the driver _recv() functions, we need to use a u32 to unmarshal the response size, otherwise a bit flip of the 31st bit would cause the expected variable to go negative, which would then try to read a huge amount of data. Also sanity check that the expected amount of data is large enough for the TPM header. Signed-off-by: Jeremy Boone <[email protected]> Cc: [email protected] Signed-off-by: James Bottomley <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> Signed-off-by: James Morris <[email protected]>
2018-02-26tpm_i2c_infineon: fix potential buffer overruns caused by bit glitches on ↵Jeremy Boone1-2/+3
the bus Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. In all the driver _recv() functions, we need to use a u32 to unmarshal the response size, otherwise a bit flip of the 31st bit would cause the expected variable to go negative, which would then try to read a huge amount of data. Also sanity check that the expected amount of data is large enough for the TPM header. Signed-off-by: Jeremy Boone <[email protected]> Cc: [email protected] Signed-off-by: James Bottomley <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> Signed-off-by: James Morris <[email protected]>
2018-02-26tpm_i2c_nuvoton: fix potential buffer overruns caused by bit glitches on the busJeremy Boone1-2/+6
Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. In all the driver _recv() functions, we need to use a u32 to unmarshal the response size, otherwise a bit flip of the 31st bit would cause the expected variable to go negative, which would then try to read a huge amount of data. Also sanity check that the expected amount of data is large enough for the TPM header. Signed-off-by: Jeremy Boone <[email protected]> Cc: [email protected] Signed-off-by: James Bottomley <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> Signed-off-by: James Morris <[email protected]>
2018-02-26tpm_tis: fix potential buffer overruns caused by bit glitches on the busJeremy Boone1-2/+3
Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. In all the driver _recv() functions, we need to use a u32 to unmarshal the response size, otherwise a bit flip of the 31st bit would cause the expected variable to go negative, which would then try to read a huge amount of data. Also sanity check that the expected amount of data is large enough for the TPM header. Signed-off-by: Jeremy Boone <[email protected]> Cc: [email protected] Signed-off-by: James Bottomley <[email protected]> Tested-by: Jarkko Sakkinen <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> Signed-off-by: James Morris <[email protected]>
2018-02-26selftests: vm: update .gitignore with new testShuah Khan1-0/+1
Update .gitignore with new test. Signed-off-by: Shuah Khan <[email protected]>
2018-02-26selftests: memory-hotplug: silence test command echoShuah Khan1-1/+1
Silence the following command being printed while running test. ./mem-on-off-test.sh -r 2 && echo "selftests: memory-hotplug [PASS]" || echo "selftests: memory-hotplug [FAIL]" Signed-off-by: Shuah Khan <[email protected]>
2018-02-26selftests/futex: Fix line continuation in MakefileDaniel Díaz1-3/+3
The Makefile lacks a couple of line continuation backslashes in an `if' clause, which produces an error when make versions prior to 4.x are used for building the tests. $ make make[1]: Entering directory `/[...]/linux/tools/testing/selftests/futex' /bin/sh: -c: line 5: syntax error: unexpected end of file make[1]: *** [all] Error 1 make[1]: Leaving directory `/[...]/linux/tools/testing/selftests/futex' make: *** [all] Error 2 Signed-off-by: Daniel Díaz <[email protected]> Signed-off-by: Shuah Khan <[email protected]>
2018-02-26cpufreq: scpi: Fix incorrect arm_big_little config dependencySudeep Holla1-3/+3
Commit 343a8d17fa8d (cpufreq: scpi: remove arm_big_little dependency) removed the SCPI cpufreq dependency on arm_big_little cpufreq driver. However the Kconfig entry still depends on ARM_BIG_LITTLE_CPUFREQ which is clearly wrong. This patch removes that unnecessary Kconfig dependency. Fixes: 343a8d17fa8d (cpufreq: scpi: remove arm_big_little dependency) Reported-by: Quentin Perret <[email protected]> Acked-by: Viresh Kumar <[email protected]> Signed-off-by: Sudeep Holla <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>
2018-02-26cpufreq: scpi: invoke frequency-invariance setter functionDietmar Eggemann1-4/+12
Commit 343a8d17fa8d (cpufreq: scpi: remove arm_big_little dependency) changed the cpufreq driver on juno from arm_big_little to scpi. The scpi set_target function does not call the frequency-invariance setter function arch_set_freq_scale() like the arm_big_little set_target function does. As a result the task scheduler load and utilization signals are not frequency-invariant on this platform anymore. Fix this by adding a call to arch_set_freq_scale() into scpi_cpufreq_set_target(). Fixes: 343a8d17fa8d (cpufreq: scpi: remove arm_big_little dependency) Signed-off-by: Dietmar Eggemann <[email protected]> Acked-by: Sudeep Holla <[email protected]> Acked-by: Viresh Kumar <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>
2018-02-26Merge branch 'idr-2018-02-06' of git://git.infradead.org/users/willy/linux-daxLinus Torvalds6-8/+75
Pull idr fixes from Matthew Wilcox: "One test-suite build fix for you and one run-time regression fix. The regression fix includes new tests to make sure they don't pop back up." * 'idr-2018-02-06' of git://git.infradead.org/users/willy/linux-dax: idr: Fix handling of IDs above INT_MAX radix tree test suite: Fix build
2018-02-26PCI: Allow release of resources that were never assignedChristian König1-0/+4
It is entirely possible that the BIOS wasn't able to assign resources to a device. In this case don't crash in pci_release_resource() when we try to resize the resource. Fixes: 8bb705e3e79d ("PCI: Add pci_resize_resource() for resizing BARs") Signed-off-by: Christian König <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> CC: [email protected] # v4.15+
2018-02-26ARM: dts: Set D-Link DNS-313 SATA to muxmode 0Linus Walleij1-1/+1
This stops the driver from trying to probe the ATA slave interface. The vendor code enables the slave interface but the driver in the vendor tree does not make use of it. Setting it to muxmode 0 disables the slave interface: the hardware only has the master interface connected to the one harddrive slot anyways. Without this change booting takes excessive time, so it is very annoying to end users. Fixes: dd5c0561db75 ("ARM: dts: Add basic devicetree for D-Link DNS-313") Signed-off-by: Linus Walleij <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]>
2018-02-26ARM: omap2: set CONFIG_LIRC=y in defconfigArnd Bergmann1-1/+1
The CONFIG_LIRC symbol has changed from 'tristate' to 'bool, so we now get a warning for omap2plus_defconfig: arch/arm/configs/omap2plus_defconfig:322:warning: symbol value 'm' invalid for LIRC This changes the file to mark the symbol as built-in to get rid of the warning. Fixes: a60d64b15c20 ("media: lirc: lirc interface should not be a raw decoder") Signed-off-by: Arnd Bergmann <[email protected]>
2018-02-26dax: fix vma_is_fsdax() helperDan Williams1-1/+1
Gerd reports that ->i_mode may contain other bits besides S_IFCHR. Use S_ISCHR() instead. Otherwise, get_user_pages_longterm() may fail on device-dax instances when those are meant to be explicitly allowed. Fixes: 2bb6d2837083 ("mm: introduce get_user_pages_longterm") Cc: <[email protected]> Reported-by: Gerd Rausch <[email protected]> Acked-by: Jane Chu <[email protected]> Reported-by: Haozhong Zhang <[email protected]> Reviewed-by: Jan Kara <[email protected]> Signed-off-by: Dan Williams <[email protected]>
2018-02-26dax: ->direct_access does not sleep anymoreBoaz Harrosh1-6/+0
In Patch: [7a862fb] brd: remove dax support Dan Williams has removed the only might_sleep implementation of ->direct_access. So we no longer need to check for it. CC: Dan Williams <[email protected]> Signed-off-by: Boaz Harrosh <[email protected]> Signed-off-by: Dan Williams <[email protected]>
2018-02-26ip_tunnel: Do not use mark in skb by defaultThomas Winter1-10/+3
This reverts commit 5c38bd1b82e1f76f9fa96c1e61c9897cabf1ce45. skb->mark contains the mark the encapsulated traffic which can result in incorrect routing decisions being made such as routing loops if the route chosen is via tunnel itself. The correct method should be to use tunnel->fwmark. Signed-off-by: Thomas Winter <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Alexey Kuznetsov <[email protected]> Cc: Hideaki YOSHIFUJI <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26bridge: Fix VLAN reference count problemIdo Schimmel1-0/+2
When a VLAN is added on a port, a reference is taken on the corresponding master VLAN entry. If it does not already exist, then it is created and a reference taken. However, in the second case a reference is not really taken when CONFIG_REFCOUNT_FULL is enabled as refcount_inc() is replaced by refcount_inc_not_zero(). Fix this by using refcount_set() on a newly created master VLAN entry. Fixes: 251277598596 ("net, bridge: convert net_bridge_vlan.refcnt from atomic_t to refcount_t") Signed-off-by: Ido Schimmel <[email protected]> Acked-by: Nikolay Aleksandrov <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26DT: net: renesas,ravb: document R8A77980 bindingsSergei Shtylyov1-0/+1
Renesas R-Car V3H (R8A77980) SoC has the R-Car gen3 compatible EtherAVB device, so document the SoC specific bindings. Signed-off-by: Sergei Shtylyov <[email protected]> Reviewed-by: Geert Uytterhoeven <[email protected]> Reviewed-by: Simon Horman <[email protected]> Reviewed-by: Rob Herring <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26qrtr: add MODULE_ALIAS macro to smdRamon Fried1-0/+1
Added MODULE_ALIAS("rpmsg:IPCRTR") to ensure qrtr-smd and qrtr will load when IPCRTR channel is detected. Signed-off-by: Ramon Fried <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26test_bpf: add a schedule pointEric Dumazet1-0/+2
test_bpf() is taking 1.6 seconds nowadays, it is time to add a schedule point in it. Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
2018-02-26idr: Fix handling of IDs above INT_MAXMatthew Wilcox2-6/+59
Khalid reported that the kernel selftests are currently failing: selftests: test_bpf.sh ======================================== test_bpf: [FAIL] not ok 1..8 selftests: test_bpf.sh [FAIL] He bisected it to 6ce711f2750031d12cec91384ac5cfa0a485b60a ("idr: Make 1-based IDRs more efficient"). The root cause is doing a signed comparison in idr_alloc_u32() instead of an unsigned comparison. I went looking for any similar problems and found a couple (which would each result in the failure to warn in two situations that aren't supposed to happen). I knocked up a few test-cases to prove that I was right and added them to the test-suite. Reported-by: Khalid Aziz <[email protected]> Tested-by: Khalid Aziz <[email protected]> Signed-off-by: Matthew Wilcox <[email protected]>
2018-02-26hdlc_ppp: carrier detect ok, don't turn off negotiationDenis Du1-1/+4
Sometimes when physical lines have a just good noise to make the protocol handshaking fail, but the carrier detect still good. Then after remove of the noise, nobody will trigger this protocol to be start again to cause the link to never come back. The fix is when the carrier is still on, not terminate the protocol handshaking. Signed-off-by: Denis Du <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26blktrace_api.h: fix comment for struct blk_user_trace_setupEric Biggers1-1/+1
'struct blk_user_trace_setup' is passed to BLKTRACESETUP, not BLKTRACESTART. Signed-off-by: Eric Biggers <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
2018-02-26tuntap: correctly add the missing XDP flushJason Wang1-0/+1
We don't flush batched XDP packets through xdp_do_flush_map(), this will cause packets stall at TX queue. Consider we don't do XDP on NAPI poll(), the only possible fix is to call xdp_do_flush_map() immediately after xdp_do_redirect(). Note, this in fact won't try to batch packets through devmap, we could address in the future. Reported-by: Christoffer Dall <[email protected]> Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Jason Wang <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26tuntap: disable preemption during XDP processingJason Wang1-0/+6
Except for tuntap, all other drivers' XDP was implemented at NAPI poll() routine in a bh. This guarantees all XDP operation were done at the same CPU which is required by e.g BFP_MAP_TYPE_PERCPU_ARRAY. But for tuntap, we do it in process context and we try to protect XDP processing by RCU reader lock. This is insufficient since CONFIG_PREEMPT_RCU can preempt the RCU reader critical section which breaks the assumption that all XDP were processed in the same CPU. Fixing this by simply disabling preemption during XDP processing. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Jason Wang <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26Revert "tuntap: add missing xdp flush"Jason Wang1-15/+0
This reverts commit 762c330d670e3d4b795cf7a8d761866fdd1eef49. The reason is we try to batch packets for devmap which causes calling xdp_do_flush() in the process context. Simply disabling preemption may not work since process may move among processors which lead xdp_do_flush() to miss some flushes on some processors. So simply revert the patch, a follow-up patch will add the xdp flush correctly. Reported-by: Christoffer Dall <[email protected]> Fixes: 762c330d670e ("tuntap: add missing xdp flush") Signed-off-by: Jason Wang <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26ixgbe: fix crash in build_skb Rx code pathEmil Tantilov1-0/+8
Add check for build_skb enabled ring in ixgbe_dma_sync_frag(). In that case &skb_shinfo(skb)->frags[0] may not always be set which can lead to a crash. Instead we derive the page offset from skb->data. Fixes: 42073d91a214 ("ixgbe: Have the CPU take ownership of the buffers sooner") CC: stable <[email protected]> Reported-by: Ambarish Soman <[email protected]> Suggested-by: Alexander Duyck <[email protected]> Signed-off-by: Emil Tantilov <[email protected]> Tested-by: Andrew Bowers <[email protected]> Signed-off-by: Jeff Kirsher <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26ARM: orion5x: Revert commit 4904dbda41c8.David S. Miller3-10/+95
It is not valid for orion5x to use mac_pton(). First of all, the orion5x buffer is not NULL terminated. mac_pton() has no business operating on non-NULL terminated buffers because only the caller can know that this is valid and in what manner it is ok to parse this NULL'less buffer. Second of all, orion5x operates on an __iomem pointer, which cannot be dereferenced using normal C pointer operations. Accesses to such areas much be performed with the proper iomem accessors. Fixes: 4904dbda41c8 ("ARM: orion5x: use mac_pton() helper") Signed-off-by: David S. Miller <[email protected]>
2018-02-26Merge tag 'edac_fixes_for_4.16' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp Pull EDAC fix from Borislav Petkov: "sb_edac: Prevent memory corruption on KNL (from Anna Karbownik)" * tag 'edac_fixes_for_4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp: EDAC, sb_edac: Fix out of bound writes during DIMM configuration on KNL
2018-02-26xfs: fix potential memory leak in mount option parsingChengguang Xu1-0/+2
When specifying string type mount option (e.g., logdev) several times in a mount, current option parsing may cause memory leak. Hence, call kfree for previous one in this case. Signed-off-by: Chengguang Xu <[email protected]> Reviewed-by: Eric Sandeen <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Signed-off-by: Darrick J. Wong <[email protected]>
2018-02-26Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds51-303/+604
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Yet another pile of melted spectrum related changes: - sanitize the array_index_nospec protection mechanism: Remove the overengineered array_index_nospec_mask_check() magic and allow const-qualified types as index to avoid temporary storage in a non-const local variable. - make the microcode loader more robust by properly propagating error codes. Provide information about new feature bits after micro code was updated so administrators can act upon. - optimizations of the entry ASM code which reduce code footprint and make the code simpler and faster. - fix the {pmd,pud}_{set,clear}_flags() implementations to work properly on paravirt kernels by removing the address translation operations. - revert the harmful vmexit_fill_RSB() optimization - use IBRS around firmware calls - teach objtool about retpolines and add annotations for indirect jumps and calls. - explicitly disable jumplabel patching in __init code and handle patching failures properly instead of silently ignoring them. - remove indirect paravirt calls for writing the speculation control MSR as these calls are obviously proving the same attack vector which is tried to be mitigated. - a few small fixes which address build issues with recent compiler and assembler versions" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits) KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely() KVM/x86: Remove indirect MSR op calls from SPEC_CTRL objtool, retpolines: Integrate objtool with retpoline support more closely x86/entry/64: Simplify ENCODE_FRAME_POINTER extable: Make init_kernel_text() global jump_label: Warn on failed jump_label patching attempt jump_label: Explicitly disable jump labels in __init code x86/entry/64: Open-code switch_to_thread_stack() x86/entry/64: Move ASM_CLAC to interrupt_entry() x86/entry/64: Remove 'interrupt' macro x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry() x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP objtool: Add module specific retpoline rules objtool: Add retpoline validation objtool: Use existing global variables for options x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute() x86/boot, objtool: Annotate indirect jump in secondary_startup_64() x86/paravirt, objtool: Annotate indirect calls ...
2018-02-26Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds26-516/+698
Pull KVM fixes from Paolo Bonzini: "s390: - optimization for the exitless interrupt support that was merged in 4.16-rc1 - improve the branch prediction blocking for nested KVM - replace some jump tables with switch statements to improve expoline performance - fixes for multiple epoch facility ARM: - fix the interaction of userspace irqchip VMs with in-kernel irqchip VMs - make sure we can build 32-bit KVM/ARM with gcc-8. x86: - fixes for AMD SEV - fixes for Intel nested VMX, emulated UMIP and a dump_stack() on VM startup - fixes for async page fault migration - small optimization to PV TLB flush (new in 4.16-rc1) - syzkaller fixes Generic: - compiler warning fixes - syzkaller fixes - more improvements to the kvm_stat tool Two more small Spectre fixes are going to reach you via Ingo" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (40 commits) KVM: SVM: Fix SEV LAUNCH_SECRET command KVM: SVM: install RSM intercept KVM: SVM: no need to call access_ok() in LAUNCH_MEASURE command include: psp-sev: Capitalize invalid length enum crypto: ccp: Fix sparse, use plain integer as NULL pointer KVM: X86: Avoid traversing all the cpus for pv tlb flush when steal time is disabled x86/kvm: Make parse_no_xxx __init for kvm KVM: x86: fix backward migration with async_PF kvm: fix warning for non-x86 builds kvm: fix warning for CONFIG_HAVE_KVM_EVENTFD builds tools/kvm_stat: print 'Total' line for multiple events only tools/kvm_stat: group child events indented after parent tools/kvm_stat: separate drilldown and fields filtering tools/kvm_stat: eliminate extra guest/pid selection dialog tools/kvm_stat: mark private methods as such tools/kvm_stat: fix debugfs handling tools/kvm_stat: print error on invalid regex tools/kvm_stat: fix crash when filtering out all non-child trace events tools/kvm_stat: avoid 'is' for equality checks tools/kvm_stat: use a more pythonic way to iterate over dictionaries ...
2018-02-26Merge branch 'l2tp-fix-API-races-discovered-by-syzbot'David S. Miller5-166/+77
James Chapman says: ==================== l2tp: fix API races discovered by syzbot This patch series addresses several races with L2TP APIs discovered by syzbot. There are no functional changes. The set of patches 1-5 in combination fix the following syzbot reports. 19c09769f WARNING in debug_print_object 347bd5acd KASAN: use-after-free Read in inet_shutdown 6e6a5ec8d general protection fault in pppol2tp_connect 9df43faf0 KASAN: use-after-free Read in pppol2tp_connect My first attempts to fix these issues were as net-next patches but the series included other refactoring and cleanup work. I was asked to separate out the bugfixes and redo for the net tree, which is what these patches are. The changes are: 1. Fix inet_shutdown races when L2TP tunnels and sessions close. (patches 1-2) 2. Fix races with tunnel and its socket. (patch 3) 3. Fix race in pppol2tp_release with session and its socket. (patch 4) 4. Fix tunnel lookup use-after-free. (patch 5) All of the syzbot reproducers hit races in the tunnel and pppol2tp session create and destroy paths. These tests create and destroy pppol2tp tunnels and sessions rapidly using multiple threads, provoking races in several tunnel/session create/destroy paths. The key problem was that each tunnel/session socket could be destroyed while its associated tunnel/session object still existed (patches 3, 4). Patch 5 addresses a problem with the way tunnels are removed from the tunnel list. Patch 5 is tagged that it addresses all four syzbot issues, though all 5 patches are needed. ==================== Signed-off-by: David S. Miller <[email protected]>
2018-02-26l2tp: fix tunnel lookup use-after-free raceJames Chapman1-7/+7
l2tp_tunnel_get walks the tunnel list to find a matching tunnel instance and if a match is found, its refcount is increased before returning the tunnel pointer. But when tunnel objects are destroyed, they are on the tunnel list after their refcount hits zero. Fix this by moving the code that removes the tunnel from the tunnel list from the tunnel socket destructor into in the l2tp_tunnel_delete path, before the tunnel refcount is decremented. refcount_t: increment on 0; use-after-free. WARNING: CPU: 3 PID: 13507 at lib/refcount.c:153 refcount_inc+0x47/0x50 Modules linked in: CPU: 3 PID: 13507 Comm: syzbot_6e6a5ec8 Not tainted 4.16.0-rc2+ #36 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:refcount_inc+0x47/0x50 RSP: 0018:ffff8800136ffb20 EFLAGS: 00010286 RAX: dffffc0000000008 RBX: ffff880017068e68 RCX: ffffffff814d3333 RDX: 0000000000000000 RSI: ffff88001a59f6d8 RDI: ffff88001a59f6d8 RBP: ffff8800136ffb28 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8800136ffab0 R11: 0000000000000000 R12: ffff880017068e50 R13: 0000000000000000 R14: ffff8800174da800 R15: 0000000000000004 FS: 00007f403ab1e700(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000205fafd2 CR3: 0000000016770000 CR4: 00000000000006e0 Call Trace: l2tp_tunnel_get+0x2dd/0x4e0 pppol2tp_connect+0x428/0x13c0 ? pppol2tp_session_create+0x170/0x170 ? __might_fault+0x115/0x1d0 ? lock_downgrade+0x860/0x860 ? __might_fault+0xe5/0x1d0 ? security_socket_connect+0x8e/0xc0 SYSC_connect+0x1b6/0x310 ? SYSC_bind+0x280/0x280 ? __do_page_fault+0x5d1/0xca0 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 SyS_connect+0x29/0x30 ? SyS_accept+0x40/0x40 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f403a42f259 RSP: 002b:00007f403ab1dee8 EFLAGS: 00000296 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00000000205fafe4 RCX: 00007f403a42f259 RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000004 RBP: 00007f403ab1df20 R08: 00007f403ab1e700 R09: 0000000000000000 R10: 00007f403ab1e700 R11: 0000000000000296 R12: 0000000000000000 R13: 00007ffc81906cbf R14: 0000000000000000 R15: 00007f403ab2b040 Code: 3b ff 5b 5d c3 e8 ca 5f 3b ff 80 3d 49 8e 66 04 00 75 ea e8 bc 5f 3b ff 48 c7 c7 60 69 64 85 c6 05 34 8e 66 04 01 e8 59 49 15 ff <0f> 0b eb ce 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 49 Fixes: f8ccac0e44934 ("l2tp: put tunnel socket release on a workqueue") Reported-and-tested-by: [email protected] Reported-and-tested-by: [email protected] Reported-and-tested-by: [email protected] Reported-and-tested-by: [email protected] Signed-off-by: James Chapman <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26l2tp: fix race in pppol2tp_release with session object destroyJames Chapman1-25/+27
pppol2tp_release uses call_rcu to put the final ref on its socket. But the session object doesn't hold a ref on the session socket so may be freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by having the session hold a ref on its socket until the session is destroyed. It is this ref that is dropped via call_rcu. Sessions are also deleted via l2tp_tunnel_closeall. This must now also put the final ref via call_rcu. So move the call_rcu call site into pppol2tp_session_close so that this happens in both destroy paths. A common destroy path should really be implemented, perhaps with l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release does, but this will be looked at later. ODEBUG: activate active (active state 1) object type: rcu_head hint: (null) WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220 Modules linked in: CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #38 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:debug_print_object+0x166/0x220 RSP: 0018:ffff880013647a00 EFLAGS: 00010082 RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0 RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0 Call Trace: debug_object_activate+0x38b/0x530 ? debug_object_assert_init+0x3b0/0x3b0 ? __mutex_unlock_slowpath+0x85/0x8b0 ? pppol2tp_session_destruct+0x110/0x110 __call_rcu.constprop.66+0x39/0x890 ? __call_rcu.constprop.66+0x39/0x890 call_rcu_sched+0x17/0x20 pppol2tp_release+0x2c7/0x440 ? fcntl_setlk+0xca0/0xca0 ? sock_alloc_file+0x340/0x340 sock_release+0x92/0x1e0 sock_close+0x1b/0x20 __fput+0x296/0x6e0 ____fput+0x1a/0x20 task_work_run+0x127/0x1a0 do_exit+0x7f9/0x2ce0 ? SYSC_connect+0x212/0x310 ? mm_update_next_owner+0x690/0x690 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 do_group_exit+0x10d/0x330 ? do_group_exit+0x330/0x330 SyS_exit_group+0x22/0x30 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f362e471259 RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259 RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000 RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60 R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000 Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e 8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 Fixes: ee40fb2e1eb5b ("l2tp: protect sock pointer of struct pppol2tp_session with RCU") Signed-off-by: James Chapman <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26l2tp: fix races with tunnel socket closeJames Chapman4-116/+42
The tunnel socket tunnel->sock (struct sock) is accessed when preparing a new ppp session on a tunnel at pppol2tp_session_init. If the socket is closed by a thread while another is creating a new session, the threads race. In pppol2tp_connect, the tunnel object may be created if the pppol2tp socket is associated with the special session_id 0 and the tunnel socket is looked up using the provided fd. When handling this, pppol2tp_connect cannot sock_hold the tunnel socket to prevent it being destroyed during pppol2tp_connect since this may itself may race with the socket being destroyed. Doing sockfd_lookup in pppol2tp_connect isn't sufficient to prevent tunnel->sock going away either because a given tunnel socket fd may be reused between calls to pppol2tp_connect. Instead, have l2tp_tunnel_create sock_hold the tunnel socket before it does sockfd_put. This ensures that the tunnel's socket is always extant while the tunnel object exists. Hold a ref on the socket until the tunnel is destroyed and ensure that all tunnel destroy paths go through a common function (l2tp_tunnel_delete) since this will do the final sock_put to release the tunnel socket. Since the tunnel's socket is now guaranteed to exist if the tunnel exists, we no longer need to use sockfd_lookup via l2tp_sock_to_tunnel to derive the tunnel from the socket since this is always sk_user_data. Also, sessions no longer sock_hold the tunnel socket since sessions already hold a tunnel ref and the tunnel sock will not be freed until the tunnel is freed. Removing these sock_holds in l2tp_session_register avoids a possible sock leak in the pppol2tp_connect error path if l2tp_session_register succeeds but attaching a ppp channel fails. The pppol2tp_connect error path could have been fixed instead and have the sock ref dropped when the session is freed, but doing a sock_put of the tunnel socket when the session is freed would require a new session_free callback. It is simpler to just remove the sock_hold of the tunnel socket in l2tp_session_register, now that the tunnel socket lifetime is guaranteed. Finally, some init code in l2tp_tunnel_create is reordered to ensure that the new tunnel object's refcount is set and the tunnel socket ref is taken before the tunnel socket destructor callbacks are set. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Modules linked in: CPU: 0 PID: 4360 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #34 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:pppol2tp_session_init+0x1d6/0x500 RSP: 0018:ffff88001377fb40 EFLAGS: 00010212 RAX: dffffc0000000000 RBX: ffff88001636a940 RCX: ffffffff84836c1d RDX: 0000000000000045 RSI: 0000000055976744 RDI: 0000000000000228 RBP: ffff88001377fb60 R08: ffffffff84836bc8 R09: 0000000000000002 R10: ffff88001377fab8 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88001636aac8 R14: ffff8800160f81c0 R15: 1ffff100026eff76 FS: 00007ffb3ea66700(0000) GS:ffff88001a400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e77000 CR3: 0000000016261000 CR4: 00000000000006f0 Call Trace: pppol2tp_connect+0xd18/0x13c0 ? pppol2tp_session_create+0x170/0x170 ? __might_fault+0x115/0x1d0 ? lock_downgrade+0x860/0x860 ? __might_fault+0xe5/0x1d0 ? security_socket_connect+0x8e/0xc0 SYSC_connect+0x1b6/0x310 ? SYSC_bind+0x280/0x280 ? __do_page_fault+0x5d1/0xca0 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 SyS_connect+0x29/0x30 ? SyS_accept+0x40/0x40 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7ffb3e376259 RSP: 002b:00007ffeda4f6508 EFLAGS: 00000202 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000020e77012 RCX: 00007ffb3e376259 RDX: 000000000000002e RSI: 0000000020e77000 RDI: 0000000000000004 RBP: 00007ffeda4f6540 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60 R13: 00007ffeda4f6660 R14: 0000000000000000 R15: 0000000000000000 Code: 80 3d b0 ff 06 02 00 0f 84 07 02 00 00 e8 13 d6 db fc 49 8d bc 24 28 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 f a 48 c1 ea 03 <80> 3c 02 00 0f 85 ed 02 00 00 4d 8b a4 24 28 02 00 00 e8 13 16 Fixes: 80d84ef3ff1dd ("l2tp: prevent l2tp_tunnel_delete racing with userspace close") Signed-off-by: James Chapman <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26l2tp: don't use inet_shutdown on ppp session destroyJames Chapman1-10/+0
Previously, if a ppp session was closed, we called inet_shutdown to mark the socket as unconnected such that userspace would get errors and then close the socket. This could race with userspace closing the socket. Instead, leave userspace to close the socket in its own time (our session will be detached anyway). BUG: KASAN: use-after-free in inet_shutdown+0x5d/0x1c0 Read of size 4 at addr ffff880010ea3ac0 by task syzbot_347bd5ac/8296 CPU: 3 PID: 8296 Comm: syzbot_347bd5ac Not tainted 4.16.0-rc1+ #91 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 Call Trace: dump_stack+0x101/0x157 ? inet_shutdown+0x5d/0x1c0 print_address_description+0x78/0x260 ? inet_shutdown+0x5d/0x1c0 kasan_report+0x240/0x360 __asan_load4+0x78/0x80 inet_shutdown+0x5d/0x1c0 ? pppol2tp_show+0x80/0x80 pppol2tp_session_close+0x68/0xb0 l2tp_tunnel_closeall+0x199/0x210 ? udp_v6_flush_pending_frames+0x90/0x90 l2tp_udp_encap_destroy+0x6b/0xc0 ? l2tp_tunnel_del_work+0x2e0/0x2e0 udpv6_destroy_sock+0x8c/0x90 sk_common_release+0x47/0x190 udp_lib_close+0x15/0x20 inet_release+0x85/0xd0 inet6_release+0x43/0x60 sock_release+0x53/0x100 ? sock_alloc_file+0x260/0x260 sock_close+0x1b/0x20 __fput+0x19f/0x380 ____fput+0x1a/0x20 task_work_run+0xd2/0x110 exit_to_usermode_loop+0x18d/0x190 do_syscall_64+0x389/0x3b0 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x7fe240a45259 RSP: 002b:00007fe241132df8 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fe240a45259 RDX: 00007fe240a45259 RSI: 0000000000000000 RDI: 00000000000000a5 RBP: 00007fe241132e20 R08: 00007fe241133700 R09: 0000000000000000 R10: 00007fe241133700 R11: 0000000000000297 R12: 0000000000000000 R13: 00007ffc49aff84f R14: 0000000000000000 R15: 00007fe241141040 Allocated by task 8331: save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0x144/0x3e0 sock_alloc_inode+0x22/0x130 alloc_inode+0x3d/0xf0 new_inode_pseudo+0x1c/0x90 sock_alloc+0x30/0x110 __sock_create+0xaa/0x4c0 SyS_socket+0xbe/0x130 do_syscall_64+0x128/0x3b0 entry_SYSCALL_64_after_hwframe+0x26/0x9b Freed by task 8314: save_stack+0x43/0xd0 __kasan_slab_free+0x11a/0x170 kasan_slab_free+0xe/0x10 kmem_cache_free+0x88/0x2b0 sock_destroy_inode+0x49/0x50 destroy_inode+0x77/0xb0 evict+0x285/0x340 iput+0x429/0x530 dentry_unlink_inode+0x28c/0x2c0 __dentry_kill+0x1e3/0x2f0 dput.part.21+0x500/0x560 dput+0x24/0x30 __fput+0x2aa/0x380 ____fput+0x1a/0x20 task_work_run+0xd2/0x110 exit_to_usermode_loop+0x18d/0x190 do_syscall_64+0x389/0x3b0 entry_SYSCALL_64_after_hwframe+0x26/0x9b Fixes: fd558d186df2c ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Signed-off-by: James Chapman <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26l2tp: don't use inet_shutdown on tunnel destroyJames Chapman1-9/+2
Previously, if a tunnel was closed, we called inet_shutdown to mark the socket as unconnected such that userspace would get errors and then close the socket. This could race with userspace closing the socket. Instead, leave userspace to close the socket in its own time (our tunnel will be detached anyway). BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0 IP: __lock_acquire+0x263/0x1630 PGD 0 P4D 0 Oops: 0000 [#1] SMP KASAN Modules linked in: CPU: 2 PID: 42 Comm: kworker/u8:2 Not tainted 4.15.0-rc7+ #129 Workqueue: l2tp l2tp_tunnel_del_work RIP: 0010:__lock_acquire+0x263/0x1630 RSP: 0018:ffff88001a37fc70 EFLAGS: 00010002 RAX: 0000000000000001 RBX: 0000000000000088 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88001a37fd18 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000076fd R12: 00000000000000a0 R13: ffff88001a3722c0 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88001ad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a0 CR3: 000000001730b000 CR4: 00000000000006e0 Call Trace: ? __lock_acquire+0xc77/0x1630 ? console_trylock+0x11/0xa0 lock_acquire+0x117/0x230 ? lock_sock_nested+0x3a/0xa0 _raw_spin_lock_bh+0x3a/0x50 ? lock_sock_nested+0x3a/0xa0 lock_sock_nested+0x3a/0xa0 inet_shutdown+0x33/0xf0 l2tp_tunnel_del_work+0x60/0xef process_one_work+0x1ea/0x5f0 ? process_one_work+0x162/0x5f0 worker_thread+0x48/0x3e0 ? trace_hardirqs_on+0xd/0x10 kthread+0x108/0x140 ? process_one_work+0x5f0/0x5f0 ? kthread_stop+0x2a0/0x2a0 ret_from_fork+0x24/0x30 Code: 00 41 81 ff ff 1f 00 00 0f 87 7a 13 00 00 45 85 f6 49 8b 85 68 08 00 00 0f 84 ae 03 00 00 c7 44 24 18 00 00 00 00 e9 f0 00 00 00 <49> 81 3c 24 80 93 3f 83 b8 00 00 00 00 44 0f 44 c0 83 fe 01 0f RIP: __lock_acquire+0x263/0x1630 RSP: ffff88001a37fc70 CR2: 00000000000000a0 Fixes: 309795f4bec2d ("l2tp: Add netlink control API for L2TP") Signed-off-by: James Chapman <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2018-02-26blockdev: Avoid two active bdev inodes for one deviceJan Kara1-2/+23
When blkdev_open() races with device removal and creation it can happen that unhashed bdev inode gets associated with newly created gendisk like: CPU0 CPU1 blkdev_open() bdev = bd_acquire() del_gendisk() bdev_unhash_inode(bdev); remove device create new device with the same number __blkdev_get() disk = get_gendisk() - gets reference to gendisk of the new device Now another blkdev_open() will not find original 'bdev' as it got unhashed, create a new one and associate it with the same 'disk' at which point problems start as we have two independent page caches for one device. Fix the problem by verifying that the bdev inode didn't get unhashed before we acquired gendisk reference. That way we make sure gendisk can get associated only with visible bdev inodes. Tested-by: Hou Tao <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
2018-02-26genhd: Fix BUG in blkdev_open()Jan Kara2-1/+21
When two blkdev_open() calls for a partition race with device removal and recreation, we can hit BUG_ON(!bd_may_claim(bdev, whole, holder)) in blkdev_open(). The race can happen as follows: CPU0 CPU1 CPU2 del_gendisk() bdev_unhash_inode(part1); blkdev_open(part1, O_EXCL) blkdev_open(part1, O_EXCL) bdev = bd_acquire() bdev = bd_acquire() blkdev_get(bdev) bd_start_claiming(bdev) - finds old inode 'whole' bd_prepare_to_claim() -> 0 bdev_unhash_inode(whole); <device removed> <new device under same number created> blkdev_get(bdev); bd_start_claiming(bdev) - finds new inode 'whole' bd_prepare_to_claim() - this also succeeds as we have different 'whole' here... - bad things happen now as we have two exclusive openers of the same bdev The problem here is that block device opens can see various intermediate states while gendisk is shutting down and then being recreated. We fix the problem by introducing new lookup_sem in gendisk that synchronizes gendisk deletion with get_gendisk() and furthermore by making sure that get_gendisk() does not return gendisk that is being (or has been) deleted. This makes sure that once we ever manage to look up newly created bdev inode, we are also guaranteed that following get_gendisk() will either return failure (and we fail open) or it returns gendisk for the new device and following bdget_disk() will return new bdev inode (i.e., blkdev_open() follows the path as if it is completely run after new device is created). Reported-and-analyzed-by: Hou Tao <[email protected]> Tested-by: Hou Tao <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
2018-02-26genhd: Fix use after free in __blkdev_get()Jan Kara1-2/+5
When two blkdev_open() calls race with device removal and recreation, __blkdev_get() can use looked up gendisk after it is freed: CPU0 CPU1 CPU2 del_gendisk(disk); bdev_unhash_inode(inode); blkdev_open() blkdev_open() bdev = bd_acquire(inode); - creates and returns new inode bdev = bd_acquire(inode); - returns the same inode __blkdev_get(devt) __blkdev_get(devt) disk = get_gendisk(devt); - got structure of device going away <finish device removal> <new device gets created under the same device number> disk = get_gendisk(devt); - got new device structure if (!bdev->bd_openers) { does the first open } if (!bdev->bd_openers) - false } else { put_disk_and_module(disk) - remember this was old device - this was last ref and disk is now freed } disk_unblock_events(disk); -> oops Fix the problem by making sure we drop reference to disk in __blkdev_get() only after we are really done with it. Reported-by: Hou Tao <[email protected]> Tested-by: Hou Tao <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
2018-02-26genhd: Add helper put_disk_and_module()Jan Kara4-27/+24
Add a proper counterpart to get_disk_and_module() - put_disk_and_module(). Currently it is opencoded in several places. Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
2018-02-26genhd: Rename get_disk() to get_disk_and_module()Jan Kara10-15/+13
Rename get_disk() to get_disk_and_module() to make sure what the function does. It's not a great name but at least it is now clear that put_disk() is not it's counterpart. Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
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