diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-05-01 07:12:14 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-03 12:26:49 +0300 |
| commit | bb086bb13b2427078b2de4ac93f10830b493e74d (patch) | |
| tree | 590928cc4a6c1e184744636ba7faf06d5a40f31c | |
| parent | 7b6bdfafaffc71ce611ab28e09eedc6a0b743832 (diff) | |
| download | linux-bb086bb13b2427078b2de4ac93f10830b493e74d.tar.xz | |
fuse: don't keep dead fuse_conn at fuse_fill_super().
commit 543b8f8662fe6d21f19958b666ab0051af9db21a upstream.
syzbot is reporting use-after-free at fuse_kill_sb_blk() [1].
Since sb->s_fs_info field is not cleared after fc was released by
fuse_conn_put() when initialization failed, fuse_kill_sb_blk() finds
already released fc and tries to hold the lock. Fix this by clearing
sb->s_fs_info field after calling fuse_conn_put().
[1] https://syzkaller.appspot.com/bug?id=a07a680ed0a9290585ca424546860464dd9658db
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+ec3986119086fe4eec97@syzkaller.appspotmail.com>
Fixes: 3b463ae0c626 ("fuse: invalidation reverse calls")
Cc: John Muir <john@jmuir.com>
Cc: Csaba Henk <csaba@gluster.com>
Cc: Anand Avati <avati@redhat.com>
Cc: <stable@vger.kernel.org> # v2.6.31
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/fuse/inode.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index ef309958e060..9b37cf8142b5 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1179,6 +1179,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) fuse_dev_free(fud); err_put_conn: fuse_conn_put(fc); + sb->s_fs_info = NULL; err_fput: fput(file); err: |