Commit 56f3ce67 authored Jul 08, 2019 by Ocean Chen Committed by Jaegeuk Kim Jul 10, 2019

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>

parent 6e0cd4a9

fs/f2fs/segment.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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];

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