From patchwork Fri Dec 16 15:06:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: huteng19901016@gmail.com X-Patchwork-Id: 13075091 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 18973C4332F for ; Fri, 16 Dec 2022 15:06:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231128AbiLPPGt (ORCPT ); Fri, 16 Dec 2022 10:06:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231290AbiLPPGo (ORCPT ); Fri, 16 Dec 2022 10:06:44 -0500 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 138DC26F9; Fri, 16 Dec 2022 07:06:44 -0800 (PST) Received: by mail-pg1-x541.google.com with SMTP id 142so1958033pga.1; Fri, 16 Dec 2022 07:06:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=qXJ+hu1W+MkDKQzyjzyjlsyWKm6yYLZxnEaJDMbEqIw=; b=k+IHLTB/7JGZrk31MrVj+wMMruLTAST2U5YIGYOVOy8xjrc4x+2qbrXG1NKRqOn68a +khpwQX/VQtNkix/4LDufLWeh8ZeOlLb7cUI3oBtFFYlS4WzfSCgZTb/WFEvdbzXnODm 2GZACVybtynEvZHGpHr64k2UeJvQDYx6mycJJDsjlQ1ttIQM0qYBYVf8hBBdImjnjoAy fr9PbnpzNCkTgIycAPkfInRLfhi4MP/UA56piOGiJr+yBLxP5y8v8CLQCTrc2Rgigxqk ozCMn2abngu0oxZt0VpDQ56KtKxBIm6Alq9YLjWDhqDvwGlVA9qkVyDP2eN9zLqiGgas UCZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=qXJ+hu1W+MkDKQzyjzyjlsyWKm6yYLZxnEaJDMbEqIw=; b=gaz7+oJSjAmwL5zF52yzUHPZJ76jAJXgqfx8uBCv0R31UIUD/VsgG2ZYeCyKvPYE3Z CjlyOmziRujOpuvEG+koGNRTCw6NE27RRAUUTweW1ODoUOSTTvA3EjvdXb6Xmj1ecK8G 0LlK2bBkX8zAkwP8lIEKvNBIxa6WHtAlmo8zV+IGHEEo+/d3WpHkMHuerpjfFST/3/8Q nFdJdqZq9aqU9Q4o461np+t4/mOpnhk2I658hNZ8EXbEubWW5crKJNk8slFPGdcEbtau DH6+DkVY1Ec1RshUKchMWEME4qxzTq7dQ4Bn3SFJkz+x1mWbx56xQw2HvBGQjkp7PdUU RR3A== X-Gm-Message-State: ANoB5pnoEpH+RJdfxXBmev2qvuaF9c4V9djrJpZNxOwSW2A4eXdfiTfa 9WlgwIJI7mE+9ITpqtJikbA= X-Google-Smtp-Source: AA0mqf53H/vN42Twc1eK2ccxzt3Q0PqfJkw+e6VijnfUxFJ3ZBzTg+/klTdnsXnTb9qPZJIzt9J9Cw== X-Received: by 2002:aa7:9041:0:b0:56c:3ed0:1f9d with SMTP id n1-20020aa79041000000b0056c3ed01f9dmr30472657pfo.17.1671203203588; Fri, 16 Dec 2022 07:06:43 -0800 (PST) Received: from localhost.localdomain ([139.177.225.252]) by smtp.gmail.com with ESMTPSA id b27-20020aa78edb000000b005772bf1b61bsm1615288pfr.67.2022.12.16.07.06.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Dec 2022 07:06:43 -0800 (PST) From: huteng19901016@gmail.com X-Google-Original-From: huteng.ht@bytedance.com To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, "huteng.ht" Subject: [PATCH] blk-mq: fix possible NULL pointer access in classic polling Date: Fri, 16 Dec 2022 23:06:36 +0800 Message-Id: <20221216150636.18111-1-huteng.ht@bytedance.com> X-Mailer: git-send-email 2.24.2 (Apple Git-127) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: "huteng.ht" Since poll method in blk_mq_ops may not be implemented by driver, add a judgement to avoid NULL pointer access. Signed-off-by: huteng.ht --- block/blk-mq.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index c5cf0dbca1db..f58f166d1c75 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4897,6 +4897,8 @@ static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie, int ret; do { + if (!q->mq_ops->poll) + break; ret = q->mq_ops->poll(hctx, iob); if (ret > 0) { __set_current_state(TASK_RUNNING);