isofs: Verify inode mode when loading from disk

commit 0a9e7405131380b57e155f10242b2e25d2e51852 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index 54075fe3de9b1f0a503343db5f04d3414a910947..d989bdcfaa26c770868a5d8f9fa8f0a40c2841d6 100644 (file)
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -1486,9 +1486,16 @@ 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: