From 2140a6b03a6141d353e93632c9a20c0471062ac5 Mon Sep 17 00:00:00 2001 From: Ocean Chen Date: Mon, 8 Jul 2019 12:34:56 +0800 Subject: [PATCH] f2fs: avoid out-of-range memory access [ Upstream commit 56f3ce675103e3fb9e631cfb4131fc768bc23e9a ] 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 Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/segment.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 8fc3edb..92f72bb 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -3261,6 +3261,11 @@ 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]; -- 2.7.4