fuse: fix leaked notify reply

commit 7fabaf303458fcabb694999d6fa772cc13d4e217 upstream.

fuse_request_send_notify_reply() may fail if the connection was reset for
some reason (e.g. fs was unmounted).  Don't leak request reference in this
case.  Besides leaking memory, this resulted in fc->num_waiting not being
decremented and hence fuse_wait_aborted() left in a hanging and unkillable
state.

Fixes: 2d45ba381a74 ("fuse: add retrieve request")
Fixes: b8f95e5d13f5 ("fuse: umount should wait for all requests")
Reported-and-tested-by: syzbot+6339eda9cb4ebbc4c37b@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> #v2.6.36
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index fe98c8b5aa1d32dc38777914e8ab87035396d99b..b4253181b5d487a66dd51b790967a97cfbd6e04a 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1715,8 +1715,10 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
        req->in.args[1].size = total_len;
 
        err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
-       if (err)
+       if (err) {
                fuse_retrieve_end(fc, req);
+               fuse_put_request(fc, req);
+       }
 
        return err;
 }