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 86e1cb8999577bb28100e1219a2a10d1004e898e..2ac3417d9412e917b1578b903207a9c41d1bee32 100644 (file)
--- 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;