isofs: Verify inode mode when loading from disk

Verify that the inode mode is sane when loading it from the disk to
avoid complaints from VFS about setting up invalid inodes.

Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/20250709095545.31062-2-jack@suse.cz
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index d5da9817df9b36a56482ff9279d463ed125e9da6..33e6a620c103e0ae6e7dc7dbdcbada2c451bb4e1 100644 (file)
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -1440,9 +1440,16 @@ static int isofs_read_inode(struct inode *inode, int relocated)
                inode->i_op = &page_symlink_inode_operations;
                inode_nohighmem(inode);
                inode->i_data.a_ops = &isofs_symlink_aops;
-       } else
+       } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
                /* XXX - parse_rock_ridge_inode() had already set i_rdev. */
                init_special_inode(inode, inode->i_mode, inode->i_rdev);
+       } else {
+               printk(KERN_DEBUG "ISOFS: Invalid file type 0%04o for inode %lu.\n",
+                       inode->i_mode, inode->i_ino);
+               ret = -EIO;
+               goto fail;
+       }
 
        ret = 0;
 out: