Commit 4c316f2f authored Sep 28, 2018 by Miklos Szeredi

fuse: set FR_SENT while locked



Otherwise fuse_dev_do_write() could come in and finish off the request, and
the set_bit(FR_SENT, ...) could trigger the WARN_ON(test_bit(FR_SENT, ...))
in request_end().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reported-by:  <syzbot+ef054c4d3f64cd7f7cec@syzkaller.appspotmai>
Fixes: 46c34a34 ("fuse: no fc->lock for pqueue parts")
Cc: <stable@vger.kernel.org> # v4.2

parent d2d2d4fb

fs/fuse/dev.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1312,8 +1312,8 @@ static ssize_t fuse_dev_do_read(struct fuse_dev fud, struct file file,
		}
		list_move_tail(&req->list, &fpq->processing);
		__fuse_get_request(req);
		spin_unlock(&fpq->lock);
		set_bit(FR_SENT, &req->flags);
		spin_unlock(&fpq->lock);
		/* matches barrier in request_wait_answer() */
		smp_mb__after_atomic();
		if (test_bit(FR_INTERRUPTED, &req->flags))