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| author | Andries E. Brouwer <Andries.Brouwer@cwi.nl> | 2007-12-17 16:19:55 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-12-17 19:28:16 -0800 |
| commit | b47b6f38e5202c924bfe7632dce5dda4e3d40731 (patch) | |
| tree | b9dfeb426adc7125ac7828d5b646d893163314c6 | |
| parent | 9e2de407bec98fb07040f658f55fb71ba1b594f5 (diff) | |
| download | linux-b47b6f38e5202c924bfe7632dce5dda4e3d40731.tar.gz linux-b47b6f38e5202c924bfe7632dce5dda4e3d40731.tar.bz2 linux-b47b6f38e5202c924bfe7632dce5dda4e3d40731.zip | |
ext3, ext4: avoid divide by zero
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@vger.kernel.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/ext3/super.c | 2 | ||||
| -rw-r--r-- | fs/ext4/super.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/fs/ext3/super.c b/fs/ext3/super.c index de55da9e28ba..cb14de1502c3 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -1676,7 +1676,7 @@ static int ext3_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_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 --git a/fs/ext4/super.c b/fs/ext4/super.c index 8031dc0e24e5..1ca0f546c466 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1797,7 +1797,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent) 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) |