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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B3917C43381 for ; Tue, 19 Feb 2019 11:44:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 83B982147A for ; Tue, 19 Feb 2019 11:44:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727464AbfBSLoH (ORCPT ); Tue, 19 Feb 2019 06:44:07 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:51833 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725767AbfBSLoG (ORCPT ); Tue, 19 Feb 2019 06:44:06 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gw3oi-0005mr-Bw; Tue, 19 Feb 2019 11:44:04 +0000 From: Colin King To: Jan Kara Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][udf-next] udf: don't call mark_buffer_dirty on a null bh pointer Date: Tue, 19 Feb 2019 11:44:03 +0000 Message-Id: <20190219114403.24771-1-colin.king@canonical.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King There is a null check on the pointer bh to avoid a null pointer dereference on bh->b_data however later bh is passed to mark_buffer_dirty that can also cause a null pointer dereference on bh. Avoid this potential null pointer dereference by moving the call to mark_buffer_dirty inside the null checked block. Fixes: e8b4274735e4 ("udf: finalize integrity descriptor before writeback") Signed-off-by: Colin Ian King --- fs/udf/super.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index a6940d90bedd..b7e9a83d39db 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -2336,13 +2336,13 @@ static int udf_sync_fs(struct super_block *sb, int wait) lvid = (struct logicalVolIntegrityDesc *)bh->b_data; udf_finalize_lvid(lvid); - } - /* - * Blockdevice will be synced later so we don't have to submit - * the buffer for IO - */ - mark_buffer_dirty(bh); + /* + * Blockdevice will be synced later so we don't have + * to submit the buffer for IO + */ + mark_buffer_dirty(bh); + } sbi->s_lvid_dirty = 0; } mutex_unlock(&sbi->s_alloc_mutex); -- 2.20.1