Change struct bpf_sock_addr_kern to use sockaddr_unspec 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_unspec cast. Signed-off-by: Kees Cook <[email protected]> --- include/linux/filter.h | 2 +- kernel/bpf/cgroup.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index f5c859b8131a..52594affe7ee 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1515,7 +1515,7 @@ static inline int bpf_tell_extensions(void) struct bpf_sock_addr_kern { struct sock *sk; - struct sockaddr *uaddr; + struct sockaddr_unspec *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 diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index af8b070e71ba..d045bc0ecc70 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -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_unspec *)&storage; ctx.uaddrlen = 0; } else { ctx.uaddrlen = *uaddrlen; -- 2.34.1
