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Patch series "mm: COW fixes part 1: fix the COW security issue for THP and swap", v3.
This series attempts to optimize and streamline the COW logic for ordinary
anon pages and THP anon pages, fixing two remaining instances of
CVE-2020-29374 in do_swap_page() and do_huge_pmd_wp_page(): information
can leak from a parent process to a child process via anonymous pages
shared during fork().
This issue, including other related COW issues, has been summarized in [2]:
"1. Observing Memory Modifications of Private Pages From A Child Process
Long story short: process-private memory might not be as private as you
think once you fork(): successive modifications of private memory
regions in the parent process can still be observed by the child
process, for example, by smart use of vmsplice()+munmap().
The core problem is that pinning pages readable in a child process, such
as done via the vmsplice system call, can result in a child process
observing memory modifications done in the parent process the child is
not supposed to observe. [1] contains an excellent summary and [2]
contains further details. This issue was assigned CVE-2020-29374 [9].
For this to trigger, it's required to use a fork() without subsequent
exec(), for example, as used under Android zygote. Without further
details about an application that forks less-privileged child processes,
one cannot really say what's actually affected and what's not -- see the
details section the end of this mail for a short sshd/openssh analysis.
While commit 17839856fd58 ("gup: document and work around "COW can break
either way" issue") fixed this issue and resulted in other problems
(e.g., ptrace on pmem), commit 09854ba94c6a ("mm: do_wp_page()
simplification") re-introduced part of the problem unfortunately.
The original reproducer can be modified quite easily to use THP [3] and
make the issue appear again on upstream kernels. I modified it to use
hugetlb [4] and it triggers as well. The problem is certainly less
severe with hugetlb than with THP; it merely highlights that we still
have plenty of open holes we should be closing/fixing.
Regarding vmsplice(), the only known workaround is to disallow the
vmsplice() system call ... or disable THP and hugetlb. But who knows
what else is affected (RDMA? O_DIRECT?) to achieve the same goal -- in
the end, it's a more generic issue"
This security issue was first reported by Jann Horn on 27 May 2020 and it
currently affects anonymous pages during swapin, anonymous THP and hugetlb.
This series tackles anonymous pages during swapin and anonymous THP:
- do_swap_page() for handling COW on PTEs during swapin directly
- do_huge_pmd_wp_page() for handling COW on PMD-mapped THP during write
faults
With this series, we'll apply the same COW logic we have in do_wp_page()
to all swappable anon pages: don't reuse (map writable) the page in
case there are additional references (page_count() != 1). All users of
reuse_swap_page() are remove, and consequently reuse_swap_page() is
removed.
In general, we're struggling with the following COW-related issues:
(1) "missed COW": we miss to copy on write and reuse the page (map it
writable) although we must copy because there are pending references
from another process to this page. The result is a security issue.
(2) "wrong COW": we copy on write although we wouldn't have to and
shouldn't: if there are valid GUP references, they will become out
of sync with the pages mapped into the page table. We fail to detect
that such a page can be reused safely, especially if never more than
a single process mapped the page. The result is an intra process
memory corruption.
(3) "unnecessary COW": we copy on write although we wouldn't have to:
performance degradation and temporary increases swap+memory
consumption can be the result.
While this series fixes (1) for swappable anon pages, it tries to reduce
reported cases of (3) first as good and easy as possible to limit the
impact when streamlining. The individual patches try to describe in
which cases we will run into (3).
This series certainly makes (2) worse for THP, because a THP will now
get PTE-mapped on write faults if there are additional references, even
if there was only ever a single process involved: once PTE-mapped, we'll
copy each and every subpage and won't reuse any subpage as long as the
underlying compound page wasn't split.
I'm working on an approach to fix (2) and improve (3): PageAnonExclusive
to mark anon pages that are exclusive to a single process, allow GUP
pins only on such exclusive pages, and allow turning exclusive pages
shared (clearing PageAnonExclusive) only if there are no GUP pins. Anon
pages with PageAnonExclusive set never have to be copied during write
faults, but eventually during fork() if they cannot be turned shared.
The improved reuse logic in this series will essentially also be the
logic to reset PageAnonExclusive. This work will certainly take a
while, but I'm planning on sharing details before having code fully
ready.
#1-#5 can be applied independently of the rest. #6-#9 are mostly only
cleanups related to reuse_swap_page().
Notes:
* For now, I'll leave hugetlb code untouched: "unnecessary COW" might
easily break existing setups because hugetlb pages are a scarce resource
and we could just end up having to crash the application when we run out
of hugetlb pages. We have to be very careful and the security aspect with
hugetlb is most certainly less relevant than for unprivileged anon pages.
* Instead of lru_add_drain() we might actually just drain the lru_add list
or even just remove the single page of interest from the lru_add list.
This would require a new helper function, and could be added if the
conditional lru_add_drain() turn out to be a problem.
* I extended the test case already included in [1] to also test for the
newly found do_swap_page() case. I'll send that out separately once/if
this part was merged.
[1] https://lkml.kernel.org/r/[email protected]
[2] https://lore.kernel.org/r/[email protected]
This patch (of 9):
Liang Zhang reported [1] that the current COW logic in do_wp_page() is
sub-optimal when it comes to swap+read fault+write fault of anonymous
pages that have a single user, visible via a performance degradation in
the redis benchmark. Something similar was previously reported [2] by
Nadav with a simple reproducer.
After we put an anon page into the swapcache and unmapped it from a single
process, that process might read that page again and refault it read-only.
If that process then writes to that page, the process is actually the
exclusive user of the page, however, the COW logic in do_co_page() won't
be able to reuse it due to the additional reference from the swapcache.
Let's optimize for pages that have been added to the swapcache but only
have an exclusive user. Try removing the swapcache reference if there is
hope that we're the exclusive user.
We will fail removing the swapcache reference in two scenarios:
(1) There are additional swap entries referencing the page: copying
instead of reusing is the right thing to do.
(2) The page is under writeback: theoretically we might be able to reuse
in some cases, however, we cannot remove the additional reference
and will have to copy.
Note that we'll only try removing the page from the swapcache when it's
highly likely that we'll be the exclusive owner after removing the page
from the swapache. As we're about to map that page writable and redirty
it, that should not affect reclaim but is rather the right thing to do.
Further, we might have additional references from the LRU pagevecs, which
will force us to copy instead of being able to reuse. We'll try handling
such references for some scenarios next. Concurrent writeback cannot be
handled easily and we'll always have to copy.
While at it, remove the superfluous page_mapcount() check: it's
implicitly covered by the page_count() for ordinary anon pages.
[1] https://lkml.kernel.org/r/[email protected]
[2] https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reported-by: Liang Zhang <[email protected]>
Reported-by: Nadav Amit <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Don Dutile <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Jan Kara <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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It's only used inside the huge_memory.c now. Don't export it and make
it static. We can thus reduce the size of huge_memory.o a bit.
Without this patch:
text data bss dec hex filename
32319 2965 4 35288 89d8 mm/huge_memory.o
With this patch:
text data bss dec hex filename
32042 2957 4 35003 88bb mm/huge_memory.o
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: William Kucharski <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Peter Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "Add hugetlb MADV_DONTNEED support", v3.
Userfaultfd selftests for hugetlb does not perform UFFD_EVENT_REMAP
testing. However, mremap support was recently added in commit
550a7d60bd5e ("mm, hugepages: add mremap() support for hugepage backed
vma"). While attempting to enable mremap support in the test, it was
discovered that the mremap test indirectly depends on MADV_DONTNEED.
madvise does not allow MADV_DONTNEED for hugetlb mappings. However, that
is primarily due to the check in can_madv_lru_vma(). By simply removing
the check and adding huge page alignment, MADV_DONTNEED can be made to
work for hugetlb mappings.
Do note that there is no compelling use case for adding this support.
This was discussed in the RFC [1]. However, adding support makes sense as
it is fairly trivial and brings hugetlb functionality more in line with
'normal' memory.
After enabling support, add selftest for MADV_DONTNEED as well as
MADV_REMOVE. Then update userfaultfd selftest.
If new functionality is accepted, then madvise man page will be updated to
indicate hugetlb is supported. It will also be updated to clarify what
happens to the passed length argument.
This patch (of 3):
MADV_DONTNEED is currently disabled for hugetlb mappings. This certainly
makes sense in shared file mappings as the pagecache maintains a reference
to the page and it will never be freed. However, it could be useful to
unmap and free pages in private mappings. In addition, userfaultfd minor
fault users may be able to simplify code by using MADV_DONTNEED.
The primary thing preventing MADV_DONTNEED from working on hugetlb
mappings is a check in can_madv_lru_vma(). To allow support for hugetlb
mappings create and use a new routine madvise_dontneed_free_valid_vma()
that allows hugetlb mappings in this specific case.
For normal mappings, madvise requires the start address be PAGE aligned
and rounds up length to the next multiple of PAGE_SIZE. Do similarly for
hugetlb mappings: require start address be huge page size aligned and
round up length to the next multiple of huge page size. Use the new
madvise_dontneed_free_valid_vma routine to check alignment and round up
length/end. zap_page_range requires this alignment for hugetlb vmas
otherwise we will hit BUGs.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Kravetz <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Mina Almasry <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Mike Rapoport <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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If LOCKDEP detects a bug while KASAN is printing a report and if
panic_on_warn is set, KASAN will not be able to finish. Disable LOCKDEP
while KASAN is printing a report.
See https://bugzilla.kernel.org/show_bug.cgi?id=202115 for an example
of the issue.
Link: https://lkml.kernel.org/r/c48a2a3288200b07e1788b77365c2f02784cfeb4.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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- Move kasan_save_enable/restore_multi_shot() declarations to
mm/kasan/kasan.h, as there is no need for them to be visible outside
of KASAN implementation.
- Only define and export these functions when KASAN tests are enabled.
- Move their definitions closer to other test-related code in report.c.
Link: https://lkml.kernel.org/r/6ba637333b78447f027d775f2d55ab1a40f63c99.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Move print_error_description()'s, report_suppressed()'s, and
report_enabled()'s definitions to improve the logical order of function
definitions in report.c.
No functional changes.
Link: https://lkml.kernel.org/r/82aa926c411e00e76e97e645a551ede9ed0c5e79.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Currently, only kasan_report() checks the KASAN_BIT_REPORTED and
KASAN_BIT_MULTI_SHOT flags.
Make other reporting routines check these flags as well.
Also add explanatory comments.
Note that the current->kasan_depth check is split out into
report_suppressed() and only called for kasan_report().
Link: https://lkml.kernel.org/r/715e346b10b398e29ba1b425299dcd79e29d58ce.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add a comment explaining why kasan_report() is the only reporting function
that uses user_access_save/restore().
Link: https://lkml.kernel.org/r/1201ca3c2be42c7bd077c53d2e46f4a51dd1476a.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Rename kasan_access_info to kasan_report_info, as the latter name better
reflects the struct's purpose.
Link: https://lkml.kernel.org/r/158a4219a5d356901d017352558c989533a0782c.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Place kasan_report_async() next to the other main reporting routines.
Also simplify printed information.
Link: https://lkml.kernel.org/r/52d942ef3ffd29bdfa225bbe8e327bc5bda7ab09.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Call print_report() in kasan_report_invalid_free() instead of calling
printing functions directly. Compared to the existing implementation of
kasan_report_invalid_free(), print_report() makes sure that the buggy
address has metadata before printing it.
The change requires adding a report type field into kasan_access_info and
using it accordingly.
kasan_report_async() is left as is, as using print_report() will only
complicate the code.
Link: https://lkml.kernel.org/r/9ea6f0604c5d2e1fb28d93dc6c44232c1f8017fe.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Merge __kasan_report() into kasan_report(). The code is simple enough to
be readable without the __kasan_report() helper.
Link: https://lkml.kernel.org/r/c8a125497ef82f7042b3795918dffb81a85a878e.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Restructure kasan_report() to make reviewing the subsequent patches
easier.
Link: https://lkml.kernel.org/r/ca28042889858b8cc4724d3d4378387f90d7a59d.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Move the addr_has_metadata() check into kasan_find_first_bad_addr().
Link: https://lkml.kernel.org/r/a49576f7a23283d786ba61579cb0c5057e8f0b9b.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Split out the part of __kasan_report() that prints things into
print_report(). One of the subsequent patches makes another error handler
use print_report() as well.
Includes lower-level changes:
- Allow addr_has_metadata() accepting a tagged address.
- Drop the const qualifier from the fields of kasan_access_info to
avoid excessive type casts.
- Change the type of the address argument of __kasan_report() and
end_report() to void * to reduce the number of type casts.
Link: https://lkml.kernel.org/r/9be3ed99dd24b9c4e1c4a848b69a0c6ecefd845e.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Move the disable_trace_on_warning() call, which enables the
/proc/sys/kernel/traceoff_on_warning interface for KASAN bugs, to
start_report(), so that it functions for all types of KASAN reports.
Link: https://lkml.kernel.org/r/7c066c5de26234ad2cebdd931adfe437f8a95d58.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Instead of duplicating calls to update_kunit_status() in every error
report routine, call it once in start_report(). Pass the sync flag as an
additional argument to start_report().
Link: https://lkml.kernel.org/r/cae5c845a0b6f3c867014e53737cdac56b11edc7.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Check the more specific CONFIG_KASAN_KUNIT_TEST config option when
defining things related to KUnit-compatible KASAN tests instead of
CONFIG_KUNIT.
Also put the kunit_kasan_status definition next to the definitons of other
KASAN-related structs.
Link: https://lkml.kernel.org/r/223592d38d2a601a160a3b2b3d5a9f9090350e62.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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- Rename kasan_update_kunit_status() to update_kunit_status() (the
function is static).
- Move the IS_ENABLED(CONFIG_KUNIT) to the function's definition
instead of duplicating it at call sites.
- Obtain and check current->kunit_test within the function.
Link: https://lkml.kernel.org/r/dac26d811ae31856c3d7666de0b108a3735d962d.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Currently, end_report() does not call trace_error_report_end() for bugs
detected in either async or asymm mode (when kasan_async_fault_possible()
returns true), as the address of the bad access might be unknown.
However, for asymm mode, the address is known for faults triggered by read
operations.
Instead of using kasan_async_fault_possible(), simply check that the addr
is not NULL when calling trace_error_report_end().
Link: https://lkml.kernel.org/r/1c8ce43f97300300e62c941181afa2eb738965c5.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Software Tag-Based mode tags stack allocations when CONFIG_KASAN_STACK
is enabled. Print task name and id in reports for stack-related bugs.
[[email protected]: include linux/sched/task_stack.h]
Link: https://lkml.kernel.org/r/d7598f11a34ed96e508f7640fa038662ed2305ec.1647099922.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/029aaa87ceadde0702f3312a34697c9139c9fb53.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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- Print at least task name and id for reports affecting allocas
(get_address_stack_frame_info() does not support them).
- Capitalize first letter of each sentence.
Link: https://lkml.kernel.org/r/aa613f097c12f7b75efb17f2618ae00480fb4bc3.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
- Move printing stack frame info before printing page info.
- Add object_is_on_stack() check to print_address_description() and add
a corresponding WARNING to kasan_print_address_stack_frame(). This
looks more in line with the rest of the checks in this function and
also allows to avoid complicating code logic wrt line breaks.
- Clean up comments related to get_address_stack_frame_info().
Link: https://lkml.kernel.org/r/1ee113a4c111df97d168c820b527cda77a3cac40.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Add a line break after each part that describes the buggy address.
Improves readability of reports.
Link: https://lkml.kernel.org/r/8682c4558e533cd0f99bdb964ce2fe741f2a9212.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Patch series "kasan: report clean-ups and improvements".
A number of clean-up patches for KASAN reporting code. Most are
non-functional and only improve readability.
This patch (of 22):
describe_object_addr() used to be called with NULL addr in the early days
of KASAN. This no longer happens, so drop the check.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/761f8e5a6ee040d665934d916a90afe9f322f745.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Print virtual mapping range and its creator in reports affecting virtual
mappings.
Also get physical page pointer for such mappings, so page information gets
printed as well.
Link: https://lkml.kernel.org/r/6ebb11210ae21253198e264d4bb0752c1fad67d7.1645548178.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
In mm/Makefile has:
obj-$(CONFIG_KASAN) += kasan/
So that we don't need 'obj-$(CONFIG_KASAN) :=' in mm/kasan/Makefile,
delete it from mm/kasan/Makefile.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: tangmeng <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Async mode support has already been implemented in commit e80a76aa1a91
("kasan, arm64: tests supports for HW_TAGS async mode") but then got
accidentally broken in commit 99734b535d9b ("kasan: detect false-positives
in tests").
Restore the changes removed by the latter patch and adapt them for asymm
mode: add a sync_fault flag to kunit_kasan_expectation that only get set
if the MTE fault was synchronous, and reenable MTE on such faults in
tests.
Also rename kunit_kasan_expectation to kunit_kasan_status and move its
definition to mm/kasan/kasan.h from include/linux/kasan.h, as this
structure is only internally used by KASAN. Also put the structure
definition under IS_ENABLED(CONFIG_KUNIT).
Link: https://lkml.kernel.org/r/133970562ccacc93ba19d754012c562351d4a8c8.1645033139.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Allow disabling vmalloc() tagging for HW_TAGS KASAN via a kasan.vmalloc
command line switch.
This is a fail-safe switch intended for production systems that enable
HW_TAGS KASAN. In case vmalloc() tagging ends up having an issue not
detected during testing but that manifests in production, kasan.vmalloc
allows to turn vmalloc() tagging off while leaving page_alloc/slab
tagging on.
Link: https://lkml.kernel.org/r/904f6d4dfa94870cc5fc2660809e093fd0d27c3b.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
- Untie kasan_init_hw_tags() code from the default values of
kasan_arg_mode and kasan_arg_stacktrace.
- Move static_branch_enable(&kasan_flag_enabled) to the end of
kasan_init_hw_tags_cpu().
- Remove excessive comments in kasan_arg_mode switch.
- Add new comments.
Link: https://lkml.kernel.org/r/76ebb340265be57a218564a497e1f52ff36a3879.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
As kasan_arg_stacktrace is only used in __init functions, mark it as
__initdata instead of __ro_after_init to allow it be freed after boot.
The other enums for KASAN args are used in kasan_init_hw_tags_cpu(), which
is not marked as __init as a CPU can be hot-plugged after boot. Clarify
this in a comment.
Link: https://lkml.kernel.org/r/7fa090865614f8e0c6c1265508efb1d429afaa50.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Suggested-by: Marco Elver <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
The kernel can use to allocate executable memory. The only supported
way to do that is via __vmalloc_node_range() with the executable bit set
in the prot argument. (vmap() resets the bit via pgprot_nx()).
Once tag-based KASAN modes start tagging vmalloc allocations, executing
code from such allocations will lead to the PC register getting a tag,
which is not tolerated by the kernel.
Only tag the allocations for normal kernel pages.
[[email protected]: pass KASAN_VMALLOC_PROT_NORMAL to kasan_unpoison_vmalloc()]
Link: https://lkml.kernel.org/r/9230ca3d3e40ffca041c133a524191fd71969a8d.1646233925.git.andreyknvl@google.com
[[email protected]: support tagged vmalloc mappings]
Link: https://lkml.kernel.org/r/2f6605e3a358cf64d73a05710cb3da356886ad29.1646233925.git.andreyknvl@google.com
[[email protected]: don't unintentionally disabled poisoning]
Link: https://lkml.kernel.org/r/de4587d6a719232e83c760113e46ed2d4d8da61e.1646757322.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/fbfd9939a4dc375923c9a5c6b9e7ab05c26b8c6b.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Add vmalloc tagging support to HW_TAGS KASAN.
The key difference between HW_TAGS and the other two KASAN modes when it
comes to vmalloc: HW_TAGS KASAN can only assign tags to physical memory.
The other two modes have shadow memory covering every mapped virtual
memory region.
Make __kasan_unpoison_vmalloc() for HW_TAGS KASAN:
- Skip non-VM_ALLOC mappings as HW_TAGS KASAN can only tag a single
mapping of normal physical memory; see the comment in the function.
- Generate a random tag, tag the returned pointer and the allocation,
and initialize the allocation at the same time.
- Propagate the tag into the page stucts to allow accesses through
page_address(vmalloc_to_page()).
The rest of vmalloc-related KASAN hooks are not needed:
- The shadow-related ones are fully skipped.
- __kasan_poison_vmalloc() is kept as a no-op with a comment.
Poisoning and zeroing of physical pages that are backing vmalloc()
allocations are skipped via __GFP_SKIP_KASAN_UNPOISON and
__GFP_SKIP_ZERO: __kasan_unpoison_vmalloc() does that instead.
Enabling CONFIG_KASAN_VMALLOC with HW_TAGS is not yet allowed.
Link: https://lkml.kernel.org/r/d19b2e9e59a9abc59d05b72dea8429dcaea739c6.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Co-developed-by: Vincenzo Frascino <[email protected]>
Signed-off-by: Vincenzo Frascino <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Add a new GFP flag __GFP_SKIP_ZERO that allows to skip memory
initialization. The flag is only effective with HW_TAGS KASAN.
This flag will be used by vmalloc code for page_alloc allocations backing
vmalloc() mappings in a following patch. The reason to skip memory
initialization for these pages in page_alloc is because vmalloc code will
be initializing them instead.
With the current implementation, when __GFP_SKIP_ZERO is provided,
__GFP_ZEROTAGS is ignored. This doesn't matter, as these two flags are
never provided at the same time. However, if this is changed in the
future, this particular implementation detail can be changed as well.
Link: https://lkml.kernel.org/r/0d53efeff345de7d708e0baa0d8829167772521e.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Add a new GFP flag __GFP_SKIP_KASAN_UNPOISON that allows skipping KASAN
poisoning for page_alloc allocations. The flag is only effective with
HW_TAGS KASAN.
This flag will be used by vmalloc code for page_alloc allocations backing
vmalloc() mappings in a following patch. The reason to skip KASAN
poisoning for these pages in page_alloc is because vmalloc code will be
poisoning them instead.
Also reword the comment for __GFP_SKIP_KASAN_POISON.
Link: https://lkml.kernel.org/r/35c97d77a704f6ff971dd3bfe4be95855744108e.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Make KASAN unpoison vmalloc mappings after they have been mapped in when
it's possible: for vmalloc() (indentified via VM_ALLOC) and vm_map_ram().
The reasons for this are:
- For vmalloc() and vm_map_ram(): pages don't get unpoisoned in case
mapping them fails.
- For vmalloc(): HW_TAGS KASAN needs pages to be mapped to set tags via
kasan_unpoison_vmalloc().
As a part of these changes, the return value of __vmalloc_node_range() is
changed to area->addr. This is a non-functional change, as
__vmalloc_area_node() returns area->addr anyway.
Link: https://lkml.kernel.org/r/fcb98980e6fcd3c4be6acdcb5d6110898ef28548.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE, a
memory region must be mapped as MT_NORMAL_TAGGED to allow setting memory
tags via MTE-specific instructions.
Add proper protection bits to vmalloc() allocations. These allocations
are always backed by page_alloc pages, so the tags will actually be
getting set on the corresponding physical memory.
Link: https://lkml.kernel.org/r/983fc33542db2f6b1e77b34ca23448d4640bbb9e.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Co-developed-by: Vincenzo Frascino <[email protected]>
Signed-off-by: Vincenzo Frascino <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Add vmalloc tagging support to SW_TAGS KASAN.
- __kasan_unpoison_vmalloc() now assigns a random pointer tag, poisons
the virtual mapping accordingly, and embeds the tag into the returned
pointer.
- __get_vm_area_node() (used by vmalloc() and vmap()) and
pcpu_get_vm_areas() save the tagged pointer into vm_struct->addr
(note: not into vmap_area->addr).
This requires putting kasan_unpoison_vmalloc() after
setup_vmalloc_vm[_locked](); otherwise the latter will overwrite the
tagged pointer. The tagged pointer then is naturally propagateed to
vmalloc() and vmap().
- vm_map_ram() returns the tagged pointer directly.
As a result of this change, vm_struct->addr is now tagged.
Enabling KASAN_VMALLOC with SW_TAGS is not yet allowed.
Link: https://lkml.kernel.org/r/4a78f3c064ce905e9070c29733aca1dd254a74f1.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
In preparation for adding vmalloc support to SW/HW_TAGS KASAN, reset
pointer tags in functions that use pointer values in range checks.
vread() is a special case here. Despite the untagging of the addr pointer
in its prologue, the accesses performed by vread() are checked.
Instead of accessing the virtual mappings though addr directly, vread()
recovers the physical address via page_address(vmalloc_to_page()) and
acceses that. And as page_address() recovers the pointer tag, the
accesses get checked.
Link: https://lkml.kernel.org/r/046003c5f683cacb0ba18e1079e9688bb3dca943.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Add wrappers around functions that [un]poison memory for vmalloc
allocations. These functions will be used by HW_TAGS KASAN and therefore
need to be disabled when kasan=off command line argument is provided.
This patch does no functional changes for software KASAN modes.
Link: https://lkml.kernel.org/r/3b8728eac438c55389fb0f9a8a2145d71dd77487.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Group functions that [de]populate shadow memory for vmalloc. Group
functions that [un]poison memory for vmalloc.
This patch does no functional changes but prepares KASAN code for adding
vmalloc support to HW_TAGS KASAN.
Link: https://lkml.kernel.org/r/aeef49eb249c206c4c9acce2437728068da74c28.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Rename kasan_free_shadow to kasan_free_module_shadow and
kasan_module_alloc to kasan_alloc_module_shadow.
These functions are used to allocate/free shadow memory for kernel modules
when KASAN_VMALLOC is not enabled. The new names better reflect their
purpose.
Also reword the comment next to their declaration to improve clarity.
Link: https://lkml.kernel.org/r/36db32bde765d5d0b856f77d2d806e838513fe84.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
In preparation for adding vmalloc support to SW_TAGS KASAN, provide a
KASAN_VMALLOC_INVALID definition for it.
HW_TAGS KASAN won't be using this value, as it falls back onto page_alloc
for poisoning freed vmalloc() memory.
Link: https://lkml.kernel.org/r/1daaaafeb148a7ae8285265edc97d7ca07b6a07d.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Most of the metadata byte values are only used for Generic KASAN.
Remove KASAN_KMALLOC_FREETRACK definition for !CONFIG_KASAN_GENERIC case,
and put it along with other metadata values for the Generic mode under a
corresponding ifdef.
Link: https://lkml.kernel.org/r/ac11d6e9e007c95e472e8fdd22efb6074ef3c6d8.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Rework the checks around kasan_unpoison_pages() call in post_alloc_hook().
The logical condition for calling this function is:
- If a software KASAN mode is enabled, we need to mark shadow memory.
- Otherwise, HW_TAGS KASAN is enabled, and it only makes sense to set
tags if they haven't already been cleared by tag_clear_highpage(),
which is indicated by init_tags.
This patch concludes the changes for post_alloc_hook().
Link: https://lkml.kernel.org/r/0ecebd0d7ccd79150e3620ea4185a32d3dfe912f.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Pull the kernel_init_free_pages() call in post_alloc_hook() out of the big
if clause for better code readability. This also allows for more
simplifications in the following patch.
This patch does no functional changes.
Link: https://lkml.kernel.org/r/a7a76456501eb37ddf9fca6529cee9555e59cdb1.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Pull the SetPageSkipKASanPoison() call in post_alloc_hook() out of the big
if clause for better code readability. This also allows for more
simplifications in the following patches.
Also turn the kasan_has_integrated_init() check into the proper
kasan_hw_tags_enabled() one. These checks evaluate to the same value, but
logically skipping kasan poisoning has nothing to do with integrated init.
Link: https://lkml.kernel.org/r/7214c1698b754ccfaa44a792113c95cc1f807c48.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Move tag_clear_highpage() loops out of the kasan_has_integrated_init()
clause as a code simplification.
This patch does no functional changes.
Link: https://lkml.kernel.org/r/587e3fc36358b88049320a89cc8dc6deaecb0cda.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Currently, the code responsible for initializing and poisoning memory in
post_alloc_hook() is scattered across two locations: kasan_alloc_pages()
hook for HW_TAGS KASAN and post_alloc_hook() itself. This is confusing.
This and a few following patches combine the code from these two
locations. Along the way, these patches do a step-by-step restructure the
many performed checks to make them easier to follow.
Replace the only caller of kasan_alloc_pages() with its implementation.
As kasan_has_integrated_init() is only true when CONFIG_KASAN_HW_TAGS is
enabled, moving the code does no functional changes.
Also move init and init_tags variables definitions out of
kasan_has_integrated_init() clause in post_alloc_hook(), as they have the
same values regardless of what the if condition evaluates to.
This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.
Link: https://lkml.kernel.org/r/5ac7e0b30f5cbb177ec363ddd7878a3141289592.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Separate code for zeroing memory from the code clearing tags in
post_alloc_hook().
This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.
This patch does no functional changes.
Link: https://lkml.kernel.org/r/2283fde963adfd8a2b29a92066f106cc16661a3c.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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