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| author | Vincenzo Frascino <vincenzo.frascino@arm.com> | 2020-12-22 21:01:49 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-22 21:55:07 +0100 |
| commit | c746170d6a48b59d1233b375905f7faef6ce80bc (patch) | |
| tree | 5443a1ff0d27d931559ae6a68b5eb7953c01a36f /mm/page_alloc.c | |
| parent | arm64: mte: switch GCR_EL1 in kernel entry and exit (diff) | |
| download | linux-c746170d6a48b59d1233b375905f7faef6ce80bc.tar.xz linux-c746170d6a48b59d1233b375905f7faef6ce80bc.zip | |
kasan, mm: untag page address in free_reserved_area
free_reserved_area() memsets the pages belonging to a given memory area.
As that memory hasn't been allocated via page_alloc, the KASAN tags that
those pages have are 0x00. As the result the memset might result in a tag
mismatch.
Untag the address to avoid spurious faults.
Link: https://lkml.kernel.org/r/ebef6425f4468d063e2f09c1b62ccbb2236b71d3.1606161801.git.andreyknvl@google.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3beeb8d722f3..1887852fb934 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7671,6 +7671,11 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char * alias for the memset(). */ direct_map_addr = page_address(page); + /* + * Perform a kasan-unchecked memset() since this memory + * has not been initialized. + */ + direct_map_addr = kasan_reset_tag(direct_map_addr); if ((unsigned int)poison <= 0xFF) memset(direct_map_addr, poison, PAGE_SIZE); |