]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
kasan: don't assume percpu shadow allocations will succeed
authorDaniel Axtens <dja@axtens.net>
Wed, 18 Dec 2019 04:51:49 +0000 (20:51 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 18 Dec 2019 04:59:59 +0000 (20:59 -0800)
commit253a496d8e57275d458eb3c988470525b0b2c545
tree13cb1452959d971018c4db8d7d0a7659884d7c2e
parente218f1ca3971e5bcaae1fe8e6f007f9a206e32e9
kasan: don't assume percpu shadow allocations will succeed

syzkaller and the fault injector showed that I was wrong to assume that
we could ignore percpu shadow allocation failures.

Handle failures properly.  Merge all the allocated areas back into the
free list and release the shadow, then clean up and return NULL.  The
shadow is released unconditionally, which relies upon the fact that the
release function is able to tolerate pages not being present.

Also clean up shadows in the recovery path - currently they are not
released, which leaks a bit of memory.

Link: http://lkml.kernel.org/r/20191205140407.1874-3-dja@axtens.net
Fixes: 3c5c3cfb9ef4 ("kasan: support backing vmalloc space with real shadow memory")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reported-by: syzbot+82e323920b78d54aaed5@syzkaller.appspotmail.com
Reported-by: syzbot+59b7daa4315e07a994f1@syzkaller.appspotmail.com
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c