f2fs: sanity check checkpoint segno and blkoff

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

Cc: stable@vger.kernel.org
Signed-off-by: Jin Qian <jinqian@google.com>
[Jaegeuk Kim: adjust minor coding style]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 83355ec..397b1e8 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1521,6 +1521,8 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
        struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
        struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
        unsigned int ovp_segments, reserved_segments;
+       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);
@@ -1542,6 +1544,20 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
                return 1;
        }
 
+       main_segs = le32_to_cpu(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;