From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E6E6C35273 for ; Tue, 5 Apr 2022 21:32:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379166AbiDEVct (ORCPT ); Tue, 5 Apr 2022 17:32:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356269AbiDEKXd (ORCPT ); Tue, 5 Apr 2022 06:23:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AEC9BAB9E; Tue, 5 Apr 2022 03:08:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B3DDC617AA; Tue, 5 Apr 2022 10:08:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE080C385A8; Tue, 5 Apr 2022 10:08:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649153285; bh=WAcl/CMtJJoJE24n0Tw8tG1yq386lGcEloJ1rQ265JU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AUqjI8gl5e3O0KQDs4eb5itPpb0V1JDtvrhtEJ4jm5RQ6B83X7LxfCeOtrqVS/vjT O4lRmMEEWvUsc49YQeY8q9hvXoAVBkJehL1YUuSvXLrs3Jf+ADg0guw6aVzVvR1Zz1 tq/tHF52VHCnWLdom+AydWhd4afjJhAbDMpwffkc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joel Jaeschke , Jens Axboe , Sasha Levin Subject: [PATCH 5.10 169/599] io_uring: terminate manual loop iterator loop correctly for non-vecs Date: Tue, 5 Apr 2022 09:27:43 +0200 Message-Id: <20220405070303.871680061@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070258.802373272@linuxfoundation.org> References: <20220405070258.802373272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jens Axboe [ Upstream commit 5e929367468c8f97cd1ffb0417316cecfebef94b ] The fix for not advancing the iterator if we're using fixed buffers is broken in that it can hit a condition where we don't terminate the loop. This results in io-wq looping forever, asking to read (or write) 0 bytes for every subsequent loop. Reported-by: Joel Jaeschke Link: https://github.com/axboe/liburing/issues/549 Fixes: 16c8d2df7ec0 ("io_uring: ensure symmetry in handling iter types in loop_rw_iter()") Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/io_uring.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index fd188b972151..82f1311dab8e 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3220,13 +3220,15 @@ static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter) ret = nr; break; } + ret += nr; if (!iov_iter_is_bvec(iter)) { iov_iter_advance(iter, nr); } else { - req->rw.len -= nr; req->rw.addr += nr; + req->rw.len -= nr; + if (!req->rw.len) + break; } - ret += nr; if (nr != iovec.iov_len) break; } -- 2.34.1