linux-kernel - [PATCH 3.16 048/370] ext4: use more strict checks for inodes_per

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 10 Mar 2017 11:46:22 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Theodore Ts'o" <tytso@....edu>,
        "Andreas Dilger" <adilger@...ger.ca>
Subject: [PATCH 3.16 048/370] ext4: use more strict checks for
 inodes_per_block on mount

3.16.42-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Theodore Ts'o <tytso@....edu>

commit cd6bb35bf7f6d7d922509bf50265383a0ceabe96 upstream.

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 <tytso@....edu>
Reviewed-by: Andreas Dilger <adilger@...ger.ca>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 fs/ext4/super.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3756,12 +3756,16 @@ static int ext4_fill_super(struct super_
 
 	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);
@@ -3845,13 +3849,6 @@ static int ext4_fill_super(struct super_
 	}
 	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);