From 5de35e8d5c02d271c20e18337e01bc20e6ef472e Mon Sep 17 00:00:00 2001 From: Lukas Czerner <lczerner@redhat.com> Date: Mon, 22 Oct 2012 18:01:19 -0400 Subject: [PATCH] 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 --- fs/ext4/mballoc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index eb1e385d8080..f05d08e13366 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -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; -- GitLab