From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934058AbdKAVWi (ORCPT ); Wed, 1 Nov 2017 17:22:38 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:35110 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933670AbdKAVWg (ORCPT ); Wed, 1 Nov 2017 17:22:36 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Jerry Lee , "Theodore Ts'o" , Willy Tarreau Subject: [PATCH 3.10 042/139] ext4: fix overflow caused by missing cast in ext4_resize_fs() Date: Wed, 1 Nov 2017 22:17:42 +0100 Message-Id: <1509571159-4405-43-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1509571159-4405-1-git-send-email-w@1wt.eu> References: <1509571159-4405-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jerry Lee commit aec51758ce10a9c847a62a48a168f8c804c6e053 upstream. On a 32-bit platform, the value of n_blcoks_count may be wrong during the file system is resized to size larger than 2^32 blocks. This may caused the superblock being corrupted with zero blocks count. Fixes: 1c6bd7173d66 Signed-off-by: Jerry Lee Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org Signed-off-by: Willy Tarreau --- fs/ext4/resize.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index cf0a704..f6190fd 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1911,7 +1911,8 @@ retry: n_desc_blocks = o_desc_blocks + le16_to_cpu(es->s_reserved_gdt_blocks); n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); - n_blocks_count = n_group * EXT4_BLOCKS_PER_GROUP(sb); + n_blocks_count = (ext4_fsblk_t)n_group * + EXT4_BLOCKS_PER_GROUP(sb); n_group--; /* set to last group number */ } -- 2.8.0.rc2.1.gbe9624a