Re: [PATCH] fs: export anon_inode_make_secure_inode() and fix secretmem LSM bypass
From: Mike Rapoport <rppt@kernel.org>
Date: 2025-06-19 11:01:32
Also in:
linux-fsdevel, linux-mm, lkml
On Thu, Jun 19, 2025 at 12:38:25PM +0200, Christian Brauner wrote:
On Thu, Jun 19, 2025 at 11:13:49AM +0200, Vlastimil Babka wrote:quoted
On 6/19/25 09:31, Shivank Garg wrote:quoted
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 thisCould we use the new EXPORT_SYMBOL_GPL_FOR_MODULES() thingy to make this explicit for KVM?Oh? Enlighten me about that, if you have a second, please.
From Documentation/core-api/symbol-namespaces.rst: The macro takes a comma separated list of module names, allowing only those modules to access this symbol. Simple tail-globs are supported. For example:: EXPORT_SYMBOL_GPL_FOR_MODULES(preempt_notifier_inc, "kvm,kvm-*") will limit usage of this symbol to modules whoes name matches the given patterns. -- Sincerely yours, Mike.