minixfs: Verify inode mode when loading from disk

The inode mode loaded from corrupted disk can be invalid. Do like what
commit 0a9e74051313 ("isofs: Verify inode mode when loading from disk")
does.

Reported-by: syzbot <syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/ec982681-84b8-4624-94fa-8af15b77cbd2@I-love.SAKURA.ne.jp
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index df9d11479caf1e11f9847df2087ff81763147122..32db676127a9eda1ea7f8982ebff6ce2a2354ff6 100644 (file)
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -492,8 +492,14 @@ void minix_set_inode(struct inode *inode, dev_t rdev)
                inode->i_op = &minix_symlink_inode_operations;
                inode_nohighmem(inode);
                inode->i_mapping->a_ops = &minix_aops;
-       } else
+       } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
                init_special_inode(inode, inode->i_mode, rdev);
+       } else {
+               printk(KERN_DEBUG "MINIX-fs: Invalid file type 0%04o for inode %lu.\n",
+                      inode->i_mode, inode->i_ino);
+               make_bad_inode(inode);
+       }
 }
 
 /*