From: Jens Axboe Date: Wed, 14 Feb 2024 15:23:05 +0000 (-0700) Subject: io_uring/net: fix multishot accept overflow handling X-Git-Tag: v6.8-rc5~18^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a37ee9e117ef73bbc2f5c0b31911afd52d229861;p=thirdparty%2Flinux.git 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 --- diff --git a/io_uring/net.c b/io_uring/net.c index 43bc9a5f96f9d..161622029147c 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)