[PATCH 4.12 107/196] f2fs: sanity check size of nat and sit cache

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jin Qian <jinqian@xxxxxxxxxxx>

commit 21d3f8e1c3b7996ce239ab6fa82e9f7a8c47d84d upstream.

Make sure number of entires doesn't exceed max journal size.

Signed-off-by: Jin Qian <jinqian@xxxxxxxxxxx>
Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/f2fs/segment.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2463,6 +2463,8 @@ static int read_normal_summaries(struct
 
 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
 {
+	struct f2fs_journal *sit_j = CURSEG_I(sbi, CURSEG_COLD_DATA)->journal;
+	struct f2fs_journal *nat_j = CURSEG_I(sbi, CURSEG_HOT_DATA)->journal;
 	int type = CURSEG_HOT_DATA;
 	int err;
 
@@ -2489,6 +2491,11 @@ static int restore_curseg_summaries(stru
 			return err;
 	}
 
+	/* sanity check for summary blocks */
+	if (nats_in_cursum(nat_j) > NAT_JOURNAL_ENTRIES ||
+			sits_in_cursum(sit_j) > SIT_JOURNAL_ENTRIES)
+		return -EINVAL;
+
 	return 0;
 }