Currently if len argument in ext4_trim_fs() is smaller than one block, the 'end' variable underflow. Avoid that by exiting right away if len is smaller than one file system block. Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx> --- fs/ext4/mballoc.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index f8b27bf..06c8526 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4989,13 +4989,18 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) int ret = 0; start = range->start >> sb->s_blocksize_bits; - end = start + (range->len >> sb->s_blocksize_bits) - 1; 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)) return -EINVAL; + + end = range->len >> sb->s_blocksize_bits; + if (0 == end) + goto out; + end += start - 1; + if (end >= max_blks) end = max_blks - 1; if (end <= first_data_blk) -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
