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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-05-01 13:12:14 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-03 11:18:45 +0200 |
| commit | e80011e53edc66401e03c834796fdde55da93aab (patch) | |
| tree | dee8c41ecb5174d685b27a232deb4a119f7df906 | |
| parent | 7863da30c256f3691963e8d41f760faaf2cb83aa (diff) | |
| download | linux-stable-e80011e53edc66401e03c834796fdde55da93aab.tar.gz linux-stable-e80011e53edc66401e03c834796fdde55da93aab.tar.bz2 linux-stable-e80011e53edc66401e03c834796fdde55da93aab.zip | |
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 230b424543ef..0ac3d6fdd28b 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1125,6 +1125,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) err_put_conn: fuse_bdi_destroy(fc); fuse_conn_put(fc); + sb->s_fs_info = NULL; err_fput: fput(file); err: |