f2fs: avoid out-of-range memory access

blkoff_off might over 512 due to fs corrupt or security
vulnerability. That should be checked before being using.

Use ENTRIES_IN_SUM to protect invalid value in cur_data_blkoff.

Signed-off-by: Ocean Chen <oceanchen@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Ocean Chen 2019-07-08 12:34:56 +08:00 committed by Jaegeuk Kim
parent 6e0cd4a9dd
commit 56f3ce6751
1 changed files with 5 additions and 0 deletions

View File

@ -3447,6 +3447,11 @@ static int read_compacted_summaries(struct f2fs_sb_info *sbi)
seg_i = CURSEG_I(sbi, i);
segno = le32_to_cpu(ckpt->cur_data_segno[i]);
blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
if (blk_off > ENTRIES_IN_SUM) {
f2fs_bug_on(sbi, 1);
f2fs_put_page(page, 1);
return -EFAULT;
}
seg_i->next_segno = segno;
reset_curseg(sbi, i, 0);
seg_i->alloc_type = ckpt->alloc_type[i];