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| author | Kees Cook <keescook@chromium.org> | 2022-02-16 10:20:47 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2022-04-12 16:11:49 -0700 |
| commit | 42db2594e4cd4a3c29aad87f80b1c00bf7751afe (patch) | |
| tree | fc6a1f3ddb556df937ed649494638a22dc730c1d | |
| parent | 4a9800c81d2f34afb66b4b42e0330ae8298019a2 (diff) | |
| download | lwn-42db2594e4cd4a3c29aad87f80b1c00bf7751afe.tar.gz lwn-42db2594e4cd4a3c29aad87f80b1c00bf7751afe.zip | |
lkdtm/heap: Note conditions for SLAB_LINEAR_OVERFLOW
It wasn't clear when SLAB_LINEAR_OVERFLOW would be expected to trip.
Explicitly describe it and include the CONFIGs in the kselftest.
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | drivers/misc/lkdtm/heap.c | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/lkdtm/config | 2 |
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm/heap.c b/drivers/misc/lkdtm/heap.c index 8a92f5a800fa..b4ac726a548f 100644 --- a/drivers/misc/lkdtm/heap.c +++ b/drivers/misc/lkdtm/heap.c @@ -22,6 +22,9 @@ static volatile int __offset = 1; /* * If there aren't guard pages, it's likely that a consecutive allocation will * let us overflow into the second allocation without overwriting something real. + * + * This should always be caught because there is an unconditional unmapped + * page after vmap allocations. */ void lkdtm_VMALLOC_LINEAR_OVERFLOW(void) { @@ -41,6 +44,9 @@ void lkdtm_VMALLOC_LINEAR_OVERFLOW(void) * This tries to stay within the next largest power-of-2 kmalloc cache * to avoid actually overwriting anything important if it's not detected * correctly. + * + * This should get caught by either memory tagging, KASan, or by using + * CONFIG_SLUB_DEBUG=y and slub_debug=ZF (or CONFIG_SLUB_DEBUG_ON=y). */ void lkdtm_SLAB_LINEAR_OVERFLOW(void) { diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config index 46f39ee76208..304123688739 100644 --- a/tools/testing/selftests/lkdtm/config +++ b/tools/testing/selftests/lkdtm/config @@ -9,3 +9,5 @@ CONFIG_UBSAN=y CONFIG_UBSAN_BOUNDS=y CONFIG_UBSAN_TRAP=y CONFIG_STACKPROTECTOR_STRONG=y +CONFIG_SLUB_DEBUG=y +CONFIG_SLUB_DEBUG_ON=y |