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 94446C7618B for ; Fri, 26 Jul 2019 13:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EC9122CED for ; Fri, 26 Jul 2019 13:45:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148742; bh=NEd6CJ+moftDEshReX8mPCqMf/mawsK+WsC3175M0eI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DA90tvt6FAITXZvJvvIQDGl1wEgKPLpBNtW8VV7Pe0/RigLQ1qjotcUzzkFEMZk3K NvBUaByy8QZ9J13qBwglq3SPrUm36/NJuuNZ9+4Xy8PozSq4FbEDt4R0YeqLWDOkdE ieq4IAVbMG/lM7HryUNRKcdU12i0XHvqbxjHDVYw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728214AbfGZNpk (ORCPT ); Fri, 26 Jul 2019 09:45:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:54750 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728170AbfGZNpj (ORCPT ); Fri, 26 Jul 2019 09:45:39 -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 390DC22CC2; Fri, 26 Jul 2019 13:45:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148738; bh=NEd6CJ+moftDEshReX8mPCqMf/mawsK+WsC3175M0eI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h+daXu19+alJbgsEWzHqgDkpGC2L0WGlgBipwL72WGInmx63IXfTuDztw+xoj6GwT HNbpK9iZV+izdNoFbvH96qeQzmIabkFq3Ch/oVYLPkG6XE6GLigX0gGpNaBXibd1Ia uB4p2uSPaxO5PcYHX/UlQOyiLg0vuCQ/Ef3rQz60= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Russell King , Al Viro , Sasha Levin Subject: [PATCH AUTOSEL 4.4 06/23] fs/adfs: super: fix use-after-free bug Date: Fri, 26 Jul 2019 09:45:05 -0400 Message-Id: <20190726134522.13308-6-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726134522.13308-1-sashal@kernel.org> References: <20190726134522.13308-1-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 4d4a0df8344f..b00ae922ece2 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