From a37ee9e117ef73bbc2f5c0b31911afd52d229861 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 14 Feb 2024 08:23:05 -0700 Subject: io_uring/net: fix multishot accept overflow handling If we hit CQ ring overflow when attempting to post a multishot accept completion, we don't properly save the result or return code. This results in losing the accepted fd value. Instead, we return the result from the poll operation that triggered the accept retry. This is generally POLLIN|POLLPRI|POLLRDNORM|POLLRDBAND which is 0xc3, or 195, which looks like a valid file descriptor, but it really has no connection to that. Handle this like we do for other multishot completions - assign the result, and return IOU_STOP_MULTISHOT to cancel any further completions from this request when overflow is hit. This preserves the result, as we should, and tells the application that the request needs to be re-armed. Cc: stable@vger.kernel.org Fixes: 515e26961295 ("io_uring: revert "io_uring fix multishot accept ordering"") Link: https://github.com/axboe/liburing/issues/1062 Signed-off-by: Jens Axboe --- io_uring/net.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/io_uring/net.c b/io_uring/net.c index 43bc9a5f96f9..161622029147 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -1372,7 +1372,7 @@ retry: * has already been done */ if (issue_flags & IO_URING_F_MULTISHOT) - ret = IOU_ISSUE_SKIP_COMPLETE; + return IOU_ISSUE_SKIP_COMPLETE; return ret; } if (ret == -ERESTARTSYS) @@ -1397,7 +1397,8 @@ retry: ret, IORING_CQE_F_MORE)) goto retry; - return -ECANCELED; + io_req_set_res(req, ret, 0); + return IOU_STOP_MULTISHOT; } int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) -- cgit v1.2.3