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Commit 5de35e8d authored by Lukas Czerner's avatar Lukas Czerner Committed by Theodore Ts'o
Browse files

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: default avatarLukas Czerner <lczerner@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
parent 79f1ba49

fs/ext4/mballoc.c

+3 −2
Original line number Original line Diff line number Diff line
@@ -4990,8 +4990,9 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) 
	minlen = EXT4_NUM_B2C(EXT4_SB(sb),

	minlen = EXT4_NUM_B2C(EXT4_SB(sb),

			      range->minlen >> sb->s_blocksize_bits);

			      range->minlen >> sb->s_blocksize_bits);





	if (unlikely(minlen > EXT4_CLUSTERS_PER_GROUP(sb)) ||

	if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||

	    unlikely(start >= max_blks))

	    start >= max_blks ||

	    range->len < sb->s_blocksize)

		return -EINVAL;

		return -EINVAL;

	if (end >= max_blks)

	if (end >= max_blks)

		end = max_blks - 1;

		end = max_blks - 1;