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 6F3D9C53210 for ; Tue, 3 Jan 2023 18:39:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233895AbjACSjj (ORCPT ); Tue, 3 Jan 2023 13:39:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233834AbjACSji (ORCPT ); Tue, 3 Jan 2023 13:39:38 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 616FC10545; Tue, 3 Jan 2023 10:39:38 -0800 (PST) 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 F2A25614E5; Tue, 3 Jan 2023 18:39:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB33AC433D2; Tue, 3 Jan 2023 18:39:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1672771177; bh=MJ5SKjpuNXN7nTVgbqgOgg57SEOydv8nZXXmH8INOWQ=; h=From:To:Cc:Subject:Date:From; b=PEXg0UzIkPrjNyYc12HuJUxPgyzLUyr2n736gofQZHCLFNSqGpYyOfQaGFhPML60I F4q5nK7SHlGZEnbXLp5Vl2JfYMtYOnDdCQnLts3VjOnCUovVs/e0a804xPhXYLrK8m RRBbFGdIbbY8lc/IGBb72PFTVgw4puGaifCRYsoQjprfQm2sGR18KBM46w6gsN2ulu tcwZmser+dmkn7f5VWDfPhC634Pczmx55/uDvYwsa/RwwGFB9j5xzAwZESSqgMsVWJ ZFv9TLkEJHZp3Hjg5H1S8lOUooajDQuLXfAUo7/JUSaCCSXf0gLV9sUMeZ8xU0PW6g RvMkwpC68KTAA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jens Axboe , syzbot+7df055631cd1be4586fd@syzkaller.appspotmail.com, Sasha Levin , io-uring@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 01/10] io_uring/cancel: re-grab ctx mutex after finishing wait Date: Tue, 3 Jan 2023 13:39:25 -0500 Message-Id: <20230103183934.2022663-1-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org From: Jens Axboe [ Upstream commit 23fffb2f09ce1145cbd751801d45ba74acaa6542 ] If we have a signal pending during cancelations, it'll cause the task_work run to return an error. Since we didn't run task_work, the current task is left in TASK_INTERRUPTIBLE state when we need to re-grab the ctx mutex, and the kernel will rightfully complain about that. Move the lock grabbing for the error cases outside the loop to avoid that issue. Reported-by: syzbot+7df055631cd1be4586fd@syzkaller.appspotmail.com Link: https://lore.kernel.org/io-uring/0000000000003a14a905f05050b0@google.com/ Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- io_uring/cancel.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/io_uring/cancel.c b/io_uring/cancel.c index 2291a53cdabd..b4f5dfacc0c3 100644 --- a/io_uring/cancel.c +++ b/io_uring/cancel.c @@ -288,24 +288,23 @@ int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg) ret = __io_sync_cancel(current->io_uring, &cd, sc.fd); + mutex_unlock(&ctx->uring_lock); if (ret != -EALREADY) break; - mutex_unlock(&ctx->uring_lock); ret = io_run_task_work_sig(ctx); - if (ret < 0) { - mutex_lock(&ctx->uring_lock); + if (ret < 0) break; - } ret = schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS); - mutex_lock(&ctx->uring_lock); if (!ret) { ret = -ETIME; break; } + mutex_lock(&ctx->uring_lock); } while (1); finish_wait(&ctx->cq_wait, &wait); + mutex_lock(&ctx->uring_lock); if (ret == -ENOENT || ret > 0) ret = 0; -- 2.35.1