kasan: adapt kmalloc_uaf2 test to HW_TAGS mode
authorAndrey Konovalov <andreyknvl@google.com>
Wed, 24 Feb 2021 20:05:38 +0000 (12:05 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 24 Feb 2021 21:38:31 +0000 (13:38 -0800)
commit1b1df4c4e2576f6b9c5b1f5f1fc9435e3f6c6b47
tree3c91c58eec459fff2f721d662592235b84202213
parent2e4bde6a1e3a3feb8511685b8c97be668728eefb
kasan: adapt kmalloc_uaf2 test to HW_TAGS mode

In the kmalloc_uaf2() test, the pointers to the two allocated memory
blocks might happen to be the same, and the test will fail. With the
software tag-based mode, the probability of the that is 1/254, so it's
hard to observe the failure. For the hardware tag-based mode though,
the probablity is 1/14, which is quite noticable.

Allow up to 16 attempts at generating different tags for the tag-based
modes.

Link: https://linux-review.googlesource.com/id/Ibfa458ef2804ff465d8eb07434a300bf36388d55
Link: https://lkml.kernel.org/r/9cd5cf2f633dcbf55cab801cd26845d2b075cec7.1610733117.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: 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>
lib/test_kasan.c