[PATCH] minixfs: Verify inode mode when loading from disk

From: Tetsuo Handa
Date: Tue Aug 12 2025 - 11:18:37 EST


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@xxxxxxxxxxxxxxxxxxxxxxxxx>
Closes: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
fs/minix/inode.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index df9d11479caf..32db676127a9 100644
--- 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);
+ }
}

/*
--
2.50.1