From: "Andries E. Brouwer" <Andries.Brouwer@xxxxxx> As it turns out, the kernel divides by EXT3_INODES_PER_GROUP(s) when mounting an ext3 filesystem. If that number is zero, a crash follows. Below a patch. This crash was reported by Joeri de Ruiter, Carst Tankink and Pim Vullers. Cc: <linux-ext4@xxxxxxxxxxxxxxx> Acked-by: Alan Cox <alan@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ext3/super.c | 2 +- fs/ext4/super.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff -puN fs/ext3/super.c~ext3-ext4-avoid-divide-by-zero fs/ext3/super.c --- a/fs/ext3/super.c~ext3-ext4-avoid-divide-by-zero +++ a/fs/ext3/super.c @@ -1676,7 +1676,7 @@ static int ext3_fill_super (struct super sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); - if (EXT3_INODE_SIZE(sb) == 0) + if (EXT3_INODE_SIZE(sb) == 0 || EXT3_INODES_PER_GROUP(sb) == 0) goto cantfind_ext3; sbi->s_inodes_per_block = blocksize / EXT3_INODE_SIZE(sb); if (sbi->s_inodes_per_block == 0) diff -puN fs/ext4/super.c~ext3-ext4-avoid-divide-by-zero fs/ext4/super.c --- a/fs/ext4/super.c~ext3-ext4-avoid-divide-by-zero +++ a/fs/ext4/super.c @@ -1797,7 +1797,7 @@ static int ext4_fill_super (struct super sbi->s_desc_size = EXT4_MIN_DESC_SIZE; 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) + 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) _ - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
