diff options
| author | Jan Kara <[email protected]> | 2022-07-26 13:13:50 +0200 |
|---|---|---|
| committer | Jan Kara <[email protected]> | 2022-07-26 13:24:04 +0200 |
| commit | fa78f336937240d1bc598db817d638086060e7e9 (patch) | |
| tree | 2ea5ad4a49ba397fce611a5fc5b8c5d4cd89d812 | |
| parent | bd6e21a9044ffc0d15cc362dcc10662e644a43bc (diff) | |
ext2: Add more validity checks for inode counts
Add checks verifying number of inodes stored in the superblock matches
the number computed from number of inodes per group. Also verify we have
at least one block worth of inodes per group. This prevents crashes on
corrupted filesystems.
Reported-by: [email protected]
Signed-off-by: Jan Kara <[email protected]>
| -rw-r--r-- | fs/ext2/super.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 300f2f0cf566..6f475d2e3b18 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -1059,9 +1059,10 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) sbi->s_frags_per_group); goto failed_mount; } - if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { + if (sbi->s_inodes_per_group < sbi->s_inodes_per_block || + sbi->s_inodes_per_group > sb->s_blocksize * 8) { ext2_msg(sb, KERN_ERR, - "error: #inodes per group too big: %lu", + "error: invalid #inodes per group: %lu", sbi->s_inodes_per_group); goto failed_mount; } @@ -1071,6 +1072,13 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) - le32_to_cpu(es->s_first_data_block) - 1) / EXT2_BLOCKS_PER_GROUP(sb)) + 1; + if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group != + le32_to_cpu(es->s_inodes_count)) { + ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu", + le32_to_cpu(es->s_inodes_count), + (u64)sbi->s_groups_count * sbi->s_inodes_per_group); + goto failed_mount; + } db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / EXT2_DESC_PER_BLOCK(sb); sbi->s_group_desc = kmalloc_array(db_count, |