cramfs: Verify inode mode when loading from disk

[ Upstream commit 7f9d34b ]

The inode mode loaded from corrupted disk can be invalid. Do like what
commit 0a9e740 ("isofs: Verify inode mode when loading from disk")
does.

Reported-by: syzbot <[email protected]>
Closes: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa <[email protected]>
Link: https://lore.kernel.org/[email protected]
Acked-by: Nicolas Pitre <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

Author: Tetsuo Handa

fs/cramfs/inode.c

@@ -117,9 +117,18 @@ static struct inode *get_cramfs_inode(struct super_block *sb,
 		inode_nohighmem(inode);
 		inode->i_data.a_ops = &cramfs_aops;
 		break;
-	default:
+	case S_IFCHR:
+	case S_IFBLK:
+	case S_IFIFO:
+	case S_IFSOCK:
 		init_special_inode(inode, cramfs_inode->mode,
 				old_decode_dev(cramfs_inode->size));
+		break;
+	default:
+		printk(KERN_DEBUG "CRAMFS: Invalid file type 0%04o for inode %lu.\n",
+		       inode->i_mode, inode->i_ino);
+		iget_failed(inode);
+		return ERR_PTR(-EIO);
 	}
 
 	inode->i_mode = cramfs_inode->mode;