From: Jin Qian <jinqian@android.com>
Date: Thu, 11 May 2017 23:15:15 +0000 (-0700)
Subject: FROMLIST: f2fs: sanity check checkpoint segno and blkoff
X-Git-Tag: release-20171130_firefly~4^2~100^2~18
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0f127e451bc737718431812019b87136521b7faa;p=firefly-linux-kernel-4.4.55.git

FROMLIST: f2fs: sanity check checkpoint segno and blkoff

Make sure segno and blkoff read from raw image are valid.

(url https://sourceforge.net/p/linux-f2fs/mailman/message/35835945)

Signed-off-by: Jin Qian <jinqian@google.com>
Bug: 36588520
Change-Id: Iba66ab97d3d0870ea48b5ef192d9075f225a934a
---

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 86e1cb899957..2ac3417d9412 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1078,6 +1078,8 @@ static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 	unsigned int total, fsmeta;
 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
+	unsigned int main_segs, blocks_per_seg;
+	int i;
 
 	total = le32_to_cpu(raw_super->segment_count);
 	fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
@@ -1089,6 +1091,22 @@ static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 	if (unlikely(fsmeta >= total))
 		return 1;
 
+	main_segs = le32_to_cpu(sbi->raw_super->segment_count_main);
+	blocks_per_seg = sbi->blocks_per_seg;
+
+	for (i = 0; i < NR_CURSEG_NODE_TYPE; i++) {
+		if (le32_to_cpu(ckpt->cur_node_segno[i]) >= main_segs ||
+		    le16_to_cpu(ckpt->cur_node_blkoff[i]) >= blocks_per_seg) {
+			return 1;
+		}
+	}
+	for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) {
+		if (le32_to_cpu(ckpt->cur_data_segno[i]) >= main_segs ||
+		    le16_to_cpu(ckpt->cur_data_blkoff[i]) >= blocks_per_seg) {
+			return 1;
+		}
+	}
+
 	if (unlikely(f2fs_cp_error(sbi))) {
 		f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
 		return 1;