]> git.karo-electronics.de Git - karo-tx-linux.git/commit
fuse: do not use iocb after it may have been freed
authorRobert Doebbelin <robert@quobyte.com>
Mon, 7 Mar 2016 08:50:56 +0000 (09:50 +0100)
committerMiklos Szeredi <miklos@szeredi.hu>
Mon, 14 Mar 2016 14:02:50 +0000 (15:02 +0100)
commit7cabc61e01a0a8b663bd2b4c982aa53048218734
tree474f0a6e0cde183d19ccb0c9b14d2358e1944012
parentb562e44f507e863c6792946e4e1b1449fbbac85d
fuse: do not use iocb after it may have been freed

There's a race in fuse_direct_IO(), whereby is_sync_kiocb() is called on an
iocb that could have been freed if async io has already completed.  The fix
in this case is simple and obvious: cache the result before starting io.

It was discovered by KASan:

kernel: ==================================================================
kernel: BUG: KASan: use after free in fuse_direct_IO+0xb1a/0xcc0 at addr ffff88036c414390

Signed-off-by: Robert Doebbelin <robert@quobyte.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: bcba24ccdc82 ("fuse: enable asynchronous processing direct IO")
Cc: <stable@vger.kernel.org> # 3.10+
fs/fuse/file.c