diff options
| author | Alexander Potapenko <glider@google.com> | 2020-02-21 07:04:30 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-28 18:38:55 +0300 |
| commit | da3418ad747fa035a1a88c6883dd2c7d7142ffc4 (patch) | |
| tree | 47d38bd75fdd4df8205e1f265ca1e96cd9a07141 /lib | |
| parent | 56ad5b4b7405ec08ef3f2b33cd59f5b3bca6577c (diff) | |
| download | linux-da3418ad747fa035a1a88c6883dd2c7d7142ffc4.tar.xz | |
lib/stackdepot.c: fix global out-of-bounds in stack_slabs
[ Upstream commit 305e519ce48e935702c32241f07d393c3c8fed3e ]
Walter Wu has reported a potential case in which init_stack_slab() is
called after stack_slabs[STACK_ALLOC_MAX_SLABS - 1] has already been
initialized. In that case init_stack_slab() will overwrite
stack_slabs[STACK_ALLOC_MAX_SLABS], which may result in a memory
corruption.
Link: http://lkml.kernel.org/r/20200218102950.260263-1-glider@google.com
Fixes: cd11016e5f521 ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/stackdepot.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/stackdepot.c b/lib/stackdepot.c index e513459a5601..3376a3291186 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -92,15 +92,19 @@ static bool init_stack_slab(void **prealloc) return true; if (stack_slabs[depot_index] == NULL) { stack_slabs[depot_index] = *prealloc; + *prealloc = NULL; } else { - stack_slabs[depot_index + 1] = *prealloc; + /* If this is the last depot slab, do not touch the next one. */ + if (depot_index + 1 < STACK_ALLOC_MAX_SLABS) { + stack_slabs[depot_index + 1] = *prealloc; + *prealloc = NULL; + } /* * This smp_store_release pairs with smp_load_acquire() from * |next_slab_inited| above and in depot_save_stack(). */ smp_store_release(&next_slab_inited, 1); } - *prealloc = NULL; return true; } |