Re: [PATCH] fs: export anon_inode_make_secure_inode() and fix secretmem LSM bypass

From: Vlastimil Babka
Date: Thu Jun 19 2025 - 05:14:49 EST


On 6/19/25 09:31, Shivank Garg wrote:
> Export anon_inode_make_secure_inode() to allow KVM guest_memfd to create
> anonymous inodes with proper security context. This replaces the current
> pattern of calling alloc_anon_inode() followed by
> inode_init_security_anon() for creating security context manually.
>
> This change also fixes a security regression in secretmem where the
> S_PRIVATE flag was not cleared after alloc_anon_inode(), causing
> LSM/SELinux checks to be bypassed for secretmem file descriptors.
>
> As guest_memfd currently resides in the KVM module, we need to export this

Could we use the new EXPORT_SYMBOL_GPL_FOR_MODULES() thingy to make this
explicit for KVM?