io_uring: drop req submit reference always in async punt

If we don't end up actually calling submit in io_sq_wq_submit_work(), we still need to drop the submit reference to the request. If we don't, then we can leak the request. This can happen if we race with ring shutdown while flushing the workqueue for requests that require use of the mm_struct. Fixes: e65ef56 ("io_uring: use regular request ref counts") Signed-off-by: Jens Axboe <[email protected]>
techwoes · May 1, 2019 · 817869d · 817869d
1 parent 52e04ef
commit 817869d
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/fs/io_uring.c b/fs/io_uring.c
@@ -1568,10 +1568,11 @@ static void io_sq_wq_submit_work(struct work_struct *work)
 					break;
 				cond_resched();
 			} while (1);
-
-			/* drop submission reference */
-			io_put_req(req);
 		}
+
+		/* drop submission reference */
+		io_put_req(req);
+
 		if (ret) {
 			io_cqring_add_event(ctx, sqe->user_data, ret, 0);
 			io_put_req(req);