From: Martin KaFai Lau martin.lau@kernel.org
[ Upstream commit ba74a7608dc12fbbd8ea36e660087f08a81ef26a ]
A latter patch refactors bpf_getsockopt(SOL_SOCKET) with the sock_getsockopt() to avoid code duplication and code drift between the two duplicates.
The current sock_getsockopt() takes sock ptr as the argument. The very first thing of this function is to get back the sk ptr by 'sk = sock->sk'.
bpf_getsockopt() could be called when the sk does not have the sock ptr created. Meaning sk->sk_socket is NULL. For example, when a passive tcp connection has just been established but has yet been accept()-ed. Thus, it cannot use the sock_getsockopt(sk->sk_socket) or else it will pass a NULL ptr.
This patch moves all sock_getsockopt implementation to the newly added sk_getsockopt(). The new sk_getsockopt() takes a sk ptr and immediately gets the sock ptr by 'sock = sk->sk_socket'
The existing sock_getsockopt(sock) is changed to call sk_getsockopt(sock->sk). All existing callers have both sock->sk and sk->sk_socket pointer.
The latter patch will make bpf_getsockopt(SOL_SOCKET) call sk_getsockopt(sk) directly. The bpf_getsockopt(SOL_SOCKET) does not use the optnames that require sk->sk_socket, so it will be safe.
Signed-off-by: Martin KaFai Lau martin.lau@kernel.org Link: https://lore.kernel.org/r/20220902002756.2887884-1-kafai@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Stable-dep-of: 5a287d3d2b9d ("lsm: fix default return value of the socket_getpeersec_*() hooks") Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/sock.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/net/core/sock.c b/net/core/sock.c index 769e969cd1dc5..95559d088a169 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1293,10 +1293,10 @@ static int groups_to_user(gid_t __user *dst, const struct group_info *src) return 0; }
-int sock_getsockopt(struct socket *sock, int level, int optname, - char __user *optval, int __user *optlen) +static int sk_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) { - struct sock *sk = sock->sk; + struct socket *sock = sk->sk_socket;
union { int val; @@ -1633,6 +1633,12 @@ int sock_getsockopt(struct socket *sock, int level, int optname, return 0; }
+int sock_getsockopt(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen) +{ + return sk_getsockopt(sock->sk, level, optname, optval, optlen); +} + /* * Initialize an sk_lock. *