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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 07D77C77B7D for ; Mon, 15 May 2023 10:39:53 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4QKbV045n4z3f4m for ; Mon, 15 May 2023 20:39:52 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.alibaba.com (client-ip=115.124.30.130; helo=out30-130.freemail.mail.aliyun.com; envelope-from=jefflexu@linux.alibaba.com; receiver=) Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4QKbTw6RdGz3bkb for ; Mon, 15 May 2023 20:39:47 +1000 (AEST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R601e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046056;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0Vigv17V_1684147181; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0Vigv17V_1684147181) by smtp.aliyun-inc.com; Mon, 15 May 2023 18:39:42 +0800 From: Jingbo Xu To: xiang@kernel.org, chao@kernel.org, huyue2@coolpad.com, linux-erofs@lists.ozlabs.org Subject: [PATCH v2] erofs: fix null-ptr-deref caused by erofs_xattr_prefixes_init Date: Mon, 15 May 2023 18:39:41 +0800 Message-Id: <20230515103941.129784-1-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.6.gb485710b MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" Fragments and dedupe share one feature bit, and thus packed inode may not exist when fragment feature bit (dedupe feature bit exactly) is set, e.g. when deduplication feature is in use while fragments feature is not. In this case, sbi->packed_inode could be NULL while fragments feature bit is set. Fix this by accessing packed inode only when it exists. Reported-by: syzbot+902d5a9373ae8f748a94@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=902d5a9373ae8f748a94 Fixes: 9e382914617c ("erofs: add helpers to load long xattr name prefixes") Signed-off-by: Jingbo Xu --- v2: polish the commit message (Gao Xiang) --- fs/erofs/xattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index cd80499351e0..bbfe7ce170d2 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -675,7 +675,7 @@ int erofs_xattr_prefixes_init(struct super_block *sb) if (!pfs) return -ENOMEM; - if (erofs_sb_has_fragments(sbi)) + if (sbi->packed_inode) buf.inode = sbi->packed_inode; else erofs_init_metabuf(&buf, sb); -- 2.19.1.6.gb485710b