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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 35A29C2BCC4 for ; Wed, 12 May 2021 16:45:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BC9E611AC for ; Wed, 12 May 2021 16:45:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244423AbhELQpy (ORCPT ); Wed, 12 May 2021 12:45:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:33526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239339AbhELQjN (ORCPT ); Wed, 12 May 2021 12:39:13 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BC4CD61CDF; Wed, 12 May 2021 16:03:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620835398; bh=gY9Pp0xiZuLgyrykZk4BpV1fMrVQZQKidXqE3FDqiKg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RRFQ82hurHulzWpN1XZRRO/emmX260szEuR4j7q7ZwWH0Ei54x7Cen/ko7x0gFwAP u9sfCcvE6LU3T2c5tw5T946Gp1yPd3OmXxggyi6Cdg/VdqgeEi6xBnE/X6Fyr/agDd 2HnMtkqeBjrFTAEjwjeGi6/5umZVjUPanI3NN9iY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , David Sterba , Sasha Levin Subject: [PATCH 5.12 327/677] btrfs: zoned: bail out in btrfs_alloc_chunk for bad input Date: Wed, 12 May 2021 16:46:13 +0200 Message-Id: <20210512144848.110528854@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144837.204217980@linuxfoundation.org> References: <20210512144837.204217980@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: stable@vger.kernel.org From: Arnd Bergmann [ Upstream commit bb05b298af8b2330db2b39971bf0029798e7ad59 ] gcc complains that the ctl->max_chunk_size member might be used uninitialized when none of the three conditions for initializing it in init_alloc_chunk_ctl_policy_zoned() are true: In function ‘init_alloc_chunk_ctl_policy_zoned’, inlined from ‘init_alloc_chunk_ctl’ at fs/btrfs/volumes.c:5023:3, inlined from ‘btrfs_alloc_chunk’ at fs/btrfs/volumes.c:5340:2: include/linux/compiler-gcc.h:48:45: error: ‘ctl.max_chunk_size’ may be used uninitialized [-Werror=maybe-uninitialized] 4998 | ctl->max_chunk_size = min(limit, ctl->max_chunk_size); | ^~~ fs/btrfs/volumes.c: In function ‘btrfs_alloc_chunk’: fs/btrfs/volumes.c:5316:32: note: ‘ctl’ declared here 5316 | struct alloc_chunk_ctl ctl; | ^~~ If we ever get into this condition, something is seriously wrong, as validity is checked in the callers btrfs_alloc_chunk init_alloc_chunk_ctl init_alloc_chunk_ctl_policy_zoned so the same logic as in init_alloc_chunk_ctl_policy_regular() and a few other places should be applied. This avoids both further data corruption, and the compile-time warning. Fixes: 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") Signed-off-by: Arnd Bergmann Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/volumes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 1c6810bbaf8b..3912eda7905f 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4989,6 +4989,8 @@ static void init_alloc_chunk_ctl_policy_zoned( ctl->max_chunk_size = 2 * ctl->max_stripe_size; ctl->devs_max = min_t(int, ctl->devs_max, BTRFS_MAX_DEVS_SYS_CHUNK); + } else { + BUG(); } /* We don't want a chunk larger than 10% of writable space */ -- 2.30.2