Commit c1a799ee authored by Kees Cook's avatar Kees Cook Committed by Jakub Kicinski
Browse files

bpf: Convert bpf_sock_addr_kern "uaddr" to sockaddr_unsized 



Change struct bpf_sock_addr_kern to use sockaddr_unsized for the "uaddr"
field instead of sockaddr. This improves type safety in the BPF cgroup
socket address filtering code.

The casting in __cgroup_bpf_run_filter_sock_addr() is updated to match the
new type, removing an unnecessary cast in the initialization and updating
the conditional assignment to use the appropriate sockaddr_unsized cast.

Additionally rename the "unspec" variable to "storage" to better align
with its usage.

No binary changes expected.

Signed-off-by: default avatarKees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-7-kees@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 8116d803

include/linux/filter.h

+1 −1
Original line number Diff line number Diff line
@@ -1515,7 +1515,7 @@ static inline int bpf_tell_extensions(void) 


struct bpf_sock_addr_kern {

	struct sock *sk;

	struct sockaddr *uaddr;

	struct sockaddr_unsized *uaddr;

	/* Temporary "register" to make indirect stores to nested structures

	 * defined above. We need three registers to make such a store, but

	 * only two (src and dst) are available at convert_ctx_access time

kernel/bpf/cgroup.c

+4 −4
Original line number Diff line number Diff line
@@ -1673,10 +1673,10 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, 
{

	struct bpf_sock_addr_kern ctx = {

		.sk = sk,

		.uaddr = (struct sockaddr *)uaddr,

		.uaddr = uaddr,

		.t_ctx = t_ctx,

	};

	struct sockaddr_storage unspec;

	struct sockaddr_storage storage;

	struct cgroup *cgrp;

	int ret;
@@ -1688,8 +1688,8 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, 
		return 0;



	if (!ctx.uaddr) {

		memset(&unspec, 0, sizeof(unspec));

		ctx.uaddr = (struct sockaddr *)&unspec;

		memset(&storage, 0, sizeof(storage));

		ctx.uaddr = (struct sockaddr_unsized *)&storage;

		ctx.uaddrlen = 0;

	} else {

		ctx.uaddrlen = *uaddrlen;