Re: [PATCH] f2fs: reject non-directory inode in f2fs_get_parent() to prevent null-ptr-deref

[Greg KH]

On Wed, Mar 18, 2026 at 05:04:10PM +0800, ZhengYuan Huang wrote:
> [BUG]
> When accessing a crafted f2fs filesystem via open_by_handle_at(2), a
> KASAN null-pointer dereference is triggered deep inside the fscrypt
> inline-encryption path:

Does the f2fs fsck tool catch this issue when run on the corrupted
image?

> The bug is reproducible on next-20260313 with our dynamic
> metadata fuzzing tool that corrupts f2fs metadata at runtime.

That is not a valid threat model, sorry.  If you can modify a filesystem
image while it is mounted, this is the least of your worries :)

thanks,

greg k-h