--- zzzz-none-000/linux-4.4.60/fs/f2fs/super.c	2017-04-08 07:53:53.000000000 +0000
+++ dragonfly-4020-701/linux-4.4.60/fs/f2fs/super.c	2018-11-08 13:36:17.000000000 +0000
@@ -898,7 +898,7 @@
 	.get_parent = f2fs_get_parent,
 };
 
-static loff_t max_file_size(unsigned bits)
+loff_t max_file_size(unsigned bits)
 {
 	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
 	loff_t leaf_count = ADDRS_PER_BLOCK;
@@ -947,6 +947,14 @@
 		return 1;
 	}
 
+	/* check log blocks per segment */
+	if (le32_to_cpu(raw_super->log_blocks_per_seg) != 9) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid log blocks per segment (%u)\n",
+			le32_to_cpu(raw_super->log_blocks_per_seg));
+		return 1;
+	}
+
 	/* Currently, support 512/1024/2048/4096 bytes sector size */
 	if (le32_to_cpu(raw_super->log_sectorsize) >
 				F2FS_MAX_LOG_SECTOR_SIZE ||
@@ -965,6 +973,13 @@
 			le32_to_cpu(raw_super->log_sectorsize));
 		return 1;
 	}
+
+	if (le32_to_cpu(raw_super->segment_count) > F2FS_MAX_SEGMENT) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid segment count (%u)",
+			le32_to_cpu(raw_super->segment_count));
+		return 1;
+	}
 	return 0;
 }
 
@@ -973,6 +988,8 @@
 	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);
@@ -984,6 +1001,22 @@
 	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;