From: Theodore Ts'o Subject: [PATCH 3/4] ext4: use more strict checks for inodes_per_block on mount Date: Fri, 18 Nov 2016 13:38:41 -0500 Message-ID: <20161118183842.25682-3-tytso@mit.edu> References: <20161118183842.25682-1-tytso@mit.edu> Cc: kernel@kyup.com, bp@alien8.de, Theodore Ts'o , stable@vger.kernel.org To: Ext4 Developers List Return-path: In-Reply-To: <20161118183842.25682-1-tytso@mit.edu> Sender: stable-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Centralize the checks for inodes_per_block and be more strict to make sure the inodes_per_block_group can't end up being zero. Signed-off-by: Theodore Ts'o Reviewed-by: Andreas Dilger Cc: stable@vger.kernel.org --- fs/ext4/super.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 404e6f3c1bed..689c02df1af4 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3668,12 +3668,16 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); - if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0) - goto cantfind_ext4; sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb); if (sbi->s_inodes_per_block == 0) goto cantfind_ext4; + if (sbi->s_inodes_per_group < sbi->s_inodes_per_block || + sbi->s_inodes_per_group > blocksize * 8) { + ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n", + sbi->s_blocks_per_group); + goto failed_mount; + } sbi->s_itb_per_group = sbi->s_inodes_per_group / sbi->s_inodes_per_block; sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb); @@ -3756,13 +3760,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } sbi->s_cluster_ratio = clustersize / blocksize; - if (sbi->s_inodes_per_group > blocksize * 8) { - ext4_msg(sb, KERN_ERR, - "#inodes per group too big: %lu", - sbi->s_inodes_per_group); - goto failed_mount; - } - /* Do we have standard group size of clustersize * 8 blocks ? */ if (sbi->s_blocks_per_group == clustersize << 3) set_opt2(sb, STD_GROUP_SIZE); -- 2.11.0.rc0.7.gbe5a750