f2fs: fix to detect corrupted meta ino

It is possible that ino of dirent or orphan inode is corrupted in a
fuzzed image, occasionally, if corrupted ino is equal to meta ino:
meta_ino, node_ino or compress_ino, caller of f2fs_iget() from below
call paths will get meta inode directly, it's not allowed, let's
add sanity check to detect such cases.

case #1
- recover_dentry
 - __f2fs_find_entry
 - f2fs_iget_retry

case #2
- recover_orphan_inode
 - f2fs_iget_retry

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index cde0a3d..93ec216 100644 (file)
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -487,6 +487,12 @@ static int do_read_inode(struct inode *inode)
        return 0;
 }
 
+static bool is_meta_ino(struct f2fs_sb_info *sbi, unsigned int ino)
+{
+       return ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi) ||
+               ino == F2FS_COMPRESS_INO(sbi);
+}
+
 struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
 {
        struct f2fs_sb_info *sbi = F2FS_SB(sb);
@@ -498,16 +504,21 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
                return ERR_PTR(-ENOMEM);
 
        if (!(inode->i_state & I_NEW)) {
+               if (is_meta_ino(sbi, ino)) {
+                       f2fs_err(sbi, "inaccessible inode: %lu, run fsck to repair", ino);
+                       set_sbi_flag(sbi, SBI_NEED_FSCK);
+                       ret = -EFSCORRUPTED;
+                       trace_f2fs_iget_exit(inode, ret);
+                       iput(inode);
+                       return ERR_PTR(ret);
+               }
+
                trace_f2fs_iget(inode);
                return inode;
        }
-       if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi))
-               goto make_now;
 
-#ifdef CONFIG_F2FS_FS_COMPRESSION
-       if (ino == F2FS_COMPRESS_INO(sbi))
+       if (is_meta_ino(sbi, ino))
                goto make_now;
-#endif
 
        ret = do_read_inode(inode);
        if (ret)