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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98E7CC2BB1D for ; Fri, 10 Apr 2020 04:02:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70F572082D for ; Fri, 10 Apr 2020 04:02:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586491372; bh=KKBWfcgXI2QAhilK8gWcaz6FAjMhjAQb240IduL7qew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=s+68MAa+mma08M+FDlhioWo2KjsLX/Zy3HvE8iJAxKazS7/mlo8iw/BHW2KkJvzdS pY2mjpIqDvymYI+CthTw0menEZCSEdF4BLyg6jO7ZiMW/pgDxJacRgUveZc6/JrY37 VWG9UQn6wYMMv4n5ODoGzHBXfp9RRRc5kBeayfT4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726009AbgDJECr (ORCPT ); Fri, 10 Apr 2020 00:02:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:57202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726902AbgDJDq6 (ORCPT ); Thu, 9 Apr 2020 23:46:58 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E7B8720CC7; Fri, 10 Apr 2020 03:46:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490418; bh=KKBWfcgXI2QAhilK8gWcaz6FAjMhjAQb240IduL7qew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cs0hAkad+6Sdjq2hsiwGR4GhylRVK5nHzcT02X5QoXLuied+Azeoel0jvGx3XdQ30 bkXfkD7RXdZZZ0oPel34mY/c1PstzReH1ISxaugXaqmILHe5d1XlrLZP99DI4hK1Tc wIve+cWxDj9zdrlLjiwWFvs1NLcm+ZJR5ffXu080= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Bart Van Assche , Ming Lei , Keith Busch , Johannes Thumshirn , Hannes Reinecke , Christoph Hellwig , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 18/68] blk-mq: Fix a recently introduced regression in blk_mq_realloc_hw_ctxs() Date: Thu, 9 Apr 2020 23:45:43 -0400 Message-Id: <20200410034634.7731-18-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200410034634.7731-1-sashal@kernel.org> References: <20200410034634.7731-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Bart Van Assche [ Upstream commit d0930bb8f46b8fb4a7d429c0bf1c91b3ed00a7cf ] q->nr_hw_queues must only be updated once it is known that blk_mq_realloc_hw_ctxs() has succeeded. Otherwise it can happen that reallocation fails and that q->nr_hw_queues is larger than the number of allocated hardware queues. This patch fixes the following crash if increasing the number of hardware queues fails: BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0x775/0x810 Write of size 8 at addr 0000000000000118 by task check/977 CPU: 3 PID: 977 Comm: check Not tainted 5.6.0-rc1-dbg+ #8 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack+0xa5/0xe6 __kasan_report.cold+0x65/0x99 kasan_report+0x16/0x20 check_memory_region+0x140/0x1b0 memset+0x28/0x40 blk_mq_map_swqueue+0x775/0x810 blk_mq_update_nr_hw_queues+0x468/0x710 nullb_device_submit_queues_store+0xf7/0x1a0 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x145/0x2c0 ksys_write+0xd7/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: ac0d6b926e74 ("block: Reduce the amount of memory required per request queue") Signed-off-by: Bart Van Assche Reviewed-by: Ming Lei Cc: Keith Busch Cc: Johannes Thumshirn Cc: Hannes Reinecke Cc: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq.c | 1 - 1 file changed, 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index d92088dec6c35..062bbf6c55958 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2824,7 +2824,6 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, memcpy(new_hctxs, hctxs, q->nr_hw_queues * sizeof(*hctxs)); q->queue_hw_ctx = new_hctxs; - q->nr_hw_queues = set->nr_hw_queues; kfree(hctxs); hctxs = new_hctxs; } -- 2.20.1