4.4-stable review patch. If anyone has any objections, please let me know.
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From: Miklos Szeredi mszeredi@redhat.com
commit 4c316f2f3ff315cb48efb7435621e5bfb81df96d upstream.
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: 46c34a348b0a ("fuse: no fc->lock for pqueue parts") Cc: stable@vger.kernel.org # v4.2 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/fuse/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1336,8 +1336,8 @@ static ssize_t fuse_dev_do_read(struct f } 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))