ext4: Avoid underflow in ext4_trim_fs()

Currently if len argument in ext4_trim_fs() is smaller than one block,
the 'end' variable underflow. Avoid that by returning EINVAL if len is
smaller than file system block.

Also remove useless unlikely().

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
This commit is contained in:
Lukas Czerner 2012-10-22 18:01:19 -04:00 committed by Theodore Ts'o
parent 79f1ba4956
commit 5de35e8d5c
1 changed files with 3 additions and 2 deletions

View File

@ -4990,8 +4990,9 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
minlen = EXT4_NUM_B2C(EXT4_SB(sb),
range->minlen >> sb->s_blocksize_bits);
if (unlikely(minlen > EXT4_CLUSTERS_PER_GROUP(sb)) ||
unlikely(start >= max_blks))
if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
start >= max_blks ||
range->len < sb->s_blocksize)
return -EINVAL;
if (end >= max_blks)
end = max_blks - 1;