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| author | Andrey Konovalov <andreyknvl@google.com> | 2021-02-26 02:20:19 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-26 18:41:03 +0100 |
| commit | 26a5ca7a73be31f76c291465680517cde37051ca (patch) | |
| tree | 70c65d14632e95c58ef2812bc3575a55327265cb /mm | |
| parent | kasan: rework krealloc tests (diff) | |
| download | linux-26a5ca7a73be31f76c291465680517cde37051ca.tar.xz linux-26a5ca7a73be31f76c291465680517cde37051ca.zip | |
kasan, mm: fail krealloc on freed objects
Currently, if krealloc() is called on a freed object with KASAN enabled,
it allocates and returns a new object, but doesn't copy any memory from
the old one as ksize() returns 0. This makes the caller believe that
krealloc() succeeded (KASAN report is printed though).
This patch adds an accessibility check into __do_krealloc(). If the check
fails, krealloc() returns NULL. This check duplicates the one in ksize();
this is fixed in the following patch.
This patch also adds a KASAN-KUnit test to check krealloc() behaviour when
it's called on a freed object.
Link: https://lkml.kernel.org/r/cbcf7b02be0a1ca11de4f833f2ff0b3f2c9b00c8.1612546384.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.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: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.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')
| -rw-r--r-- | mm/slab_common.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index 897c3a446b04..4aedb8455352 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1136,6 +1136,9 @@ static __always_inline void *__do_krealloc(const void *p, size_t new_size, void *ret; size_t ks; + if (likely(!ZERO_OR_NULL_PTR(p)) && !kasan_check_byte(p)) + return NULL; + ks = ksize(p); if (ks >= new_size) { |