Re: [PATCH v5 bpf-next 0/3] bpf: add bpf_init_inode_xattr kfunc for atomic inode labeling

["Kumar Kartikeya Dwivedi" <memxor@gmail.com>]

On Wed Jul 8, 2026 at 2:09 AM CEST, David Windsor wrote:
> Many in-kernel LSMs (SELinux, Smack, IMA) store security labels in
> extended attributes. For these LSMs, atomic labeling during inode
> creation is critical: if the inode becomes accessible before its xattr
> is set, it is briefly unlabeled, which can disrupt LSMs making policy
> decisions based on file labels.
>
> Existing LSMs solve this by setting xattrs directly in the
> inode_init_security hook, which runs before the inode becomes
> accessible. BPF LSM programs currently lack this capability because
> the hook uses an output parameter (xattr_count) that BPF programs
> cannot write to, and existing kfuncs like bpf_set_dentry_xattr
> require a dentry that isn't available until after the inode is
> accessible.
>
> This series introduces the bpf_init_inode_xattr() kfunc, which takes
> the combined inode_init_security xattr context argument and claims a
> slot in it via the new security_lsmxattr_add() LSM helper.
>

There are various CI failures in newly added tests, I don't think any of them
are passing. Please fix before respinning.

https://github.com/kernel-patches/bpf/pull/12730

E.g. both test_init_inode_xattr and test_init_inode_xattr_slot do not have
expected results.

pw-bot: cr

> [...]