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| author | Guenter Roeck <linux@roeck-us.net> | 2024-04-02 16:38:39 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-12 12:11:31 +0300 |
| commit | d8c42a6e61d842555be9fb778700ec8e9a5215e1 (patch) | |
| tree | c2514485c620c73a29ca7ff56b90911fbae26447 | |
| parent | d0f14ae223c2421b334c1f1a9e48f1e809aee3a0 (diff) | |
| download | linux-d8c42a6e61d842555be9fb778700ec8e9a5215e1.tar.xz | |
mm/slub, kunit: Use inverted data to corrupt kmem cache
[ Upstream commit b1080c667b3b2c8c38a7fa83ca5567124887abae ]
Two failure patterns are seen randomly when running slub_kunit tests with
CONFIG_SLAB_FREELIST_RANDOM and CONFIG_SLAB_FREELIST_HARDENED enabled.
Pattern 1:
# test_clobber_zone: pass:1 fail:0 skip:0 total:1
ok 1 test_clobber_zone
# test_next_pointer: EXPECTATION FAILED at lib/slub_kunit.c:72
Expected 3 == slab_errors, but
slab_errors == 0 (0x0)
# test_next_pointer: EXPECTATION FAILED at lib/slub_kunit.c:84
Expected 2 == slab_errors, but
slab_errors == 0 (0x0)
# test_next_pointer: pass:0 fail:1 skip:0 total:1
not ok 2 test_next_pointer
In this case, test_next_pointer() overwrites p[s->offset], but the data
at p[s->offset] is already 0x12.
Pattern 2:
ok 1 test_clobber_zone
# test_next_pointer: EXPECTATION FAILED at lib/slub_kunit.c:72
Expected 3 == slab_errors, but
slab_errors == 2 (0x2)
# test_next_pointer: pass:0 fail:1 skip:0 total:1
not ok 2 test_next_pointer
In this case, p[s->offset] has a value other than 0x12, but one of the
expected failures is nevertheless missing.
Invert data instead of writing a fixed value to corrupt the cache data
structures to fix the problem.
Fixes: 1f9f78b1b376 ("mm/slub, kunit: add a KUnit test for SLUB debugging functionality")
Cc: Oliver Glitta <glittao@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
CC: Daniel Latypov <dlatypov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | lib/slub_kunit.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c index d4a3730b08fa..4ce960438806 100644 --- a/lib/slub_kunit.c +++ b/lib/slub_kunit.c @@ -55,7 +55,7 @@ static void test_next_pointer(struct kunit *test) ptr_addr = (unsigned long *)(p + s->offset); tmp = *ptr_addr; - p[s->offset] = 0x12; + p[s->offset] = ~p[s->offset]; /* * Expecting three errors. |