From fcd5df35882b128ef3e160fab3074e6fe7ae501b Mon Sep 17 00:00:00 2001 From: Mingming Cao Date: Sun, 25 Jun 2006 05:47:50 -0700 Subject: [PATCH] Avoid disk sector_t overflow for >2TB ext3 filesystem If ext3 filesystem is larger than 2TB, and sector_t is a u32 (i.e. CONFIG_LBD not defined in the kernel), the calculation of the disk sector will overflow. Add check at ext3_fill_super() and ext3_group_extend() to prevent mount/remount/resize >2TB ext3 filesystem if sector_t size is 4 bytes. Verified this patch on a 32 bit platform without CONFIG_LBD defined (sector_t is 32 bits long), mount refuse to mount a 10TB ext3. Signed-off-by: Mingming Cao Acked-by: Andreas Dilger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext3/super.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'fs/ext3/super.c') diff --git a/fs/ext3/super.c b/fs/ext3/super.c index a60cc6ec130f..df98a7709252 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -1565,6 +1565,16 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent) goto failed_mount; } + if (le32_to_cpu(es->s_blocks_count) > + (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { + printk(KERN_ERR "EXT3-fs: filesystem on %s:" + " too large to mount safely\n", sb->s_id); + if (sizeof(sector_t) < 8) + printk(KERN_WARNING "EXT3-fs: CONFIG_LBD not " + "enabled\n"); + goto failed_mount; + } + if (EXT3_BLOCKS_PER_GROUP(sb) == 0) goto cantfind_ext3; sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) - -- cgit v1.2.3-59-g8ed1b