[v2,6/8] bpf: Leverage sockptr_t in BPF setsockopt hook

Message ID 20230808134049.1407498-7-leitao@debian.org
State New
Headers
Series io_uring: Initial support for {s,g}etsockopt commands |

Commit Message

Breno Leitao Aug. 8, 2023, 1:40 p.m. UTC
  Move BPF setsockopt hook (__cgroup_bpf_run_filter_setsockopt()) to use
sockptr instead of user pointers. This brings flexibility to the
function, since it could be called with userspace or kernel pointers.

This also aligns with the getsockopt() counterpart, which is now using
sockptr_t types.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 include/linux/bpf-cgroup.h | 2 +-
 kernel/bpf/cgroup.c        | 5 +++--
 net/socket.c               | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)
  

Patch

diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index d16cb99fd4f1..5e3419eb267a 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -137,7 +137,7 @@  int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   enum cgroup_bpf_attach_type atype);
 
 int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int *level,
-				       int *optname, char __user *optval,
+				       int *optname, sockptr_t optval,
 				       int *optlen, char **kernel_optval);
 
 int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index ebc8c58f7e46..f0dedd4f7f2e 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1785,7 +1785,7 @@  static bool sockopt_buf_allocated(struct bpf_sockopt_kern *ctx,
 }
 
 int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
-				       int *optname, char __user *optval,
+				       int *optname, sockptr_t optval,
 				       int *optlen, char **kernel_optval)
 {
 	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
@@ -1808,7 +1808,8 @@  int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
 
 	ctx.optlen = *optlen;
 
-	if (copy_from_user(ctx.optval, optval, min(*optlen, max_optlen)) != 0) {
+	if (copy_from_sockptr(ctx.optval, optval,
+			      min(*optlen, max_optlen))) {
 		ret = -EFAULT;
 		goto out;
 	}
diff --git a/net/socket.c b/net/socket.c
index c686c6e89441..b7d22633995a 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2241,7 +2241,7 @@  int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 
 	if (!in_compat_syscall())
 		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
-						     user_optval, &optlen,
+						     optval, &optlen,
 						     &kernel_optval);
 	if (err < 0)
 		goto out_put;