[PATCH]

PATCH In review Andries E. Brouwer 2 participants 2 messages Dec 3, 2007 ext4 file system

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Andries E. Brouwer

author

2007-12-03 16:26 UTC #0 lore raw

PATCH 1/1 [PATCH]

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.

Andries

fs/ext3/super.c +1 -1

diff -uprN -X /linux/dontdiff a/fs/ext3/super.c b/fs/ext3/super.c
@@ -1596,7 +1596,7 @@ 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)

fs/ext4/super.c +1 -1

diff -uprN -X /linux/dontdiff a/fs/ext4/super.c b/fs/ext4/super.c
@@ -1678,7 +1678,7 @@ static int ext4_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 (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)

Alan Cox

Acked-by on v1 1/1

2007-12-03 17:11 UTC #1 lore raw

Quoted 5 lines · On Mon, 3 Dec 2007 16:54:55 +0100 "Andries E. Brouwer"…

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.

Acked-by Alan Cox <[email protected]>