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=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 4BBF5C7618B for ; Fri, 26 Jul 2019 13:52:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B56322CEC for ; Fri, 26 Jul 2019 13:52:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564149157; bh=xDfCWhVDseD5mMcFkZluXYrX2Kjuu5L7Kf1DwzxIokc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jrlxeE6JhT4+1+F9E3Cq17TWr3W8Yv36cFvjRjbs20g3WX1+rmm8y9+4SJR/6mhGg 0mxoDXmvKKorKTRfqRAEZYYxP4SGMPZII7wi8yVdqEFrIwYFFDcetF0t8KhITwV3Sx tfbRbcMUhUzInr99Zwj1M+o+D60l6plvQadj9SWs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388811AbfGZNwg (ORCPT ); Fri, 26 Jul 2019 09:52:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:51716 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388305AbfGZNnr (ORCPT ); Fri, 26 Jul 2019 09:43:47 -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 A55D522CD2; Fri, 26 Jul 2019 13:43:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148627; bh=xDfCWhVDseD5mMcFkZluXYrX2Kjuu5L7Kf1DwzxIokc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aMWNxyLd/QnOnPY7+ZZTp0tZVmfUNx70S5RQ908opU4/xaOeWcA+yj0YvNVkwO8bl Y04VC+dEUC1zm489eJBGKsT27LWYie18PFQKcuqc79RFKgpojjV4NJ3Hg5SA2+fOyN JJ4oF9X3S2PtEqN6j8XmzA7Kwm+sI6pvO5Zvxerk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Russell King , Al Viro , Sasha Levin Subject: [PATCH AUTOSEL 4.14 10/37] fs/adfs: super: fix use-after-free bug Date: Fri, 26 Jul 2019 09:43:05 -0400 Message-Id: <20190726134332.12626-10-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726134332.12626-1-sashal@kernel.org> References: <20190726134332.12626-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Russell King [ Upstream commit 5808b14a1f52554de612fee85ef517199855e310 ] Fix a use-after-free bug during filesystem initialisation, where we access the disc record (which is stored in a buffer) after we have released the buffer. Signed-off-by: Russell King Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- fs/adfs/super.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/adfs/super.c b/fs/adfs/super.c index c9fdfb112933..e42c30001509 100644 --- a/fs/adfs/super.c +++ b/fs/adfs/super.c @@ -368,6 +368,7 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent) struct buffer_head *bh; struct object_info root_obj; unsigned char *b_data; + unsigned int blocksize; struct adfs_sb_info *asb; struct inode *root; int ret = -EINVAL; @@ -419,8 +420,10 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent) goto error_free_bh; } + blocksize = 1 << dr->log2secsize; brelse(bh); - if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { + + if (sb_set_blocksize(sb, blocksize)) { bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); if (!bh) { adfs_error(sb, "couldn't read superblock on " -- 2.20.1