diff options
| author | Kees Cook | 2020-06-25 13:37:02 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2020-06-29 18:41:39 +0200 |
| commit | e12145cf1c3a8077e6d9f575711e38dd7d8a3ebc (patch) | |
| tree | 76020d7c0b5da911be0fa25896002c89579325b7 /drivers/misc/lkdtm/heap.c | |
| parent | 464e86b4abadfc490f426954b431e2ec6a9d7bd2 (diff) | |
lkdtm/heap: Avoid edge and middle of slabs
Har har, after I moved the slab freelist pointer into the middle of the
slab, now it looks like the contents are getting poisoned. Adjust the
test to avoid the freelist pointer again.
Fixes: 3202fa62fb43 ("slub: relocate freelist pointer to middle of object")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200625203704.317097-3-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/lkdtm/heap.c')
| -rw-r--r-- | drivers/misc/lkdtm/heap.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/misc/lkdtm/heap.c b/drivers/misc/lkdtm/heap.c index 3c5cec85edce..1323bc16f113 100644 --- a/drivers/misc/lkdtm/heap.c +++ b/drivers/misc/lkdtm/heap.c @@ -58,11 +58,12 @@ void lkdtm_READ_AFTER_FREE(void) int *base, *val, saw; size_t len = 1024; /* - * The slub allocator uses the first word to store the free - * pointer in some configurations. Use the middle of the - * allocation to avoid running into the freelist + * The slub allocator will use the either the first word or + * the middle of the allocation to store the free pointer, + * depending on configurations. Store in the second word to + * avoid running into the freelist. */ - size_t offset = (len / sizeof(*base)) / 2; + size_t offset = sizeof(*base); base = kmalloc(len, GFP_KERNEL); if (!base) { |