Re: [PATCH bpf-next 2/6] bpf: Add ksock kfuncs

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Missing rollback of pernet subsystem on initialization error paths in `bpf_ksock_kfunc_init`.
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commit c26355c87f06c9eb5cc9cceccb20cfce50aa1e1e
Author: Mahe Tardy <mahe.tardy@gmail.com>

bpf: Add ksock kfuncs

This commit introduces BPF kfuncs to allow BPF LSM and SYSCALL programs to
create and use sockets for sending data. It adds several lifecycle and usage
kfuncs for kernel sockets, limits socket creation via a per-namespace sysctl,
and registers the necessary BTF kfuncs.

> diff --git a/net/core/bpf_ksock.c b/net/core/bpf_ksock.c
> new file mode 100644
> index 0000000000000..8bde734bc917d
> --- /dev/null
> +++ b/net/core/bpf_ksock.c

[ ... ]

> +static int __init bpf_ksock_kfunc_init(void)
> +{
> +	int ret;
> +	const struct btf_id_dtor_kfunc bpf_ksock_dtors[] = {
> +		{
> +			.btf_id = bpf_ksock_dtor_ids[0],
> +			.kfunc_btf_id = bpf_ksock_dtor_ids[1],
> +		},
> +	};
> +
> +	ret = register_pernet_subsys(&bpf_ksock_net_ops);
> +	if (ret)
> +		return ret;
> +
> +	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL,
> +					&ksock_init_kfunc_set);
> +	if (ret) {
> +		unregister_pernet_subsys(&bpf_ksock_net_ops);
> +		return ret;
> +	}
> +
> +	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL,
> +					&ksock_kfunc_set);
> +	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM,
> +					       &ksock_kfunc_set);
> +	return ret = ret ?: register_btf_id_dtor_kfuncs(bpf_ksock_dtors,
> +						 ARRAY_SIZE(bpf_ksock_dtors),
> +						 THIS_MODULE);

[Severity: Medium]
If the later register_btf_kfunc_id_set() or register_btf_id_dtor_kfuncs()
calls fail in bpf_ksock_kfunc_init(), does this leak the pernet operations
registration?

The earlier error path for BPF_PROG_TYPE_SYSCALL registration properly
calls unregister_pernet_subsys(&bpf_ksock_net_ops). If these subsequent
registrations fail, the function returns the error directly without cleaning
up the pernet subsystem.

> +}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260706093525.13030-1-mahe.tardy@gmail.com?part=2