When determining last group through ext4_get_group_no_and_offset() the result may be wrong in cases when range->start and range-len are too big, because it may overflow when summing up those two numbers. Fix that by checking range->len and limit its value to ext4_blocks_count(). This commit was tested by myself with expected result. Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx> --- fs/ext4/mballoc.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 5b4d4e3..5f3e8a3 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4819,6 +4819,7 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) ext4_group_t group, ngroups = ext4_get_groups_count(sb); ext4_grpblk_t cnt = 0, first_block, last_block; uint64_t start, len, minlen, trimmed; + ext4_fsblk_t blocks_count = ext4_blocks_count(EXT4_SB(sb)->s_es); int ret = 0; start = range->start >> sb->s_blocksize_bits; @@ -4826,6 +4827,11 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) minlen = range->minlen >> sb->s_blocksize_bits; trimmed = 0; + if (start >= blocks_count) + return -EINVAL; + if (start + len > blocks_count) + len = blocks_count - start; + if (unlikely(minlen > EXT4_BLOCKS_PER_GROUP(sb))) return -EINVAL; -- 1.7.2.3 -- 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
