net: Change sock_getsockopt() to take the sk ptr instead of the sock ptr

[ 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>
This commit is contained in:
Martin KaFai Lau 2022-09-01 17:27:56 -07:00 committed by Ksawlii
parent 2629b60313
commit 126751e8ed

View file

@ -1417,10 +1417,10 @@ static int groups_to_user(gid_t __user *dst, const struct group_info *src)
return 0; return 0;
} }
int sock_getsockopt(struct socket *sock, int level, int optname, static int sk_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen) char __user *optval, int __user *optlen)
{ {
struct sock *sk = sock->sk; struct socket *sock = sk->sk_socket;
union { union {
int val; int val;
@ -1764,6 +1764,12 @@ lenout:
return 0; 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. * Initialize an sk_lock.
* *