Commit e34a07c0 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Paolo Abeni
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sock: redo the psock vs ULP protection check 



Commit 8a59f9d1 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()")
has moved the inet_csk_has_ulp(sk) check from sk_psock_init() to
the new tcp_bpf_update_proto() function. I'm guessing that this
was done to allow creating psocks for non-inet sockets.

Unfortunately the destruction path for psock includes the ULP
unwind, so we need to fail the sk_psock_init() itself.
Otherwise if ULP is already present we'll notice that later,
and call tcp_update_ulp() with the sk_proto of the ULP
itself, which will most likely result in the ULP looping
its callbacks.

Fixes: 8a59f9d1 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()")
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Reviewed-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Reviewed-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Tested-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20220620191353.1184629-2-kuba@kernel.org


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 1b205d94

include/net/inet_sock.h

+5 −0
Original line number Diff line number Diff line
@@ -253,6 +253,11 @@ struct inet_sock { 
#define IP_CMSG_CHECKSUM	BIT(7)

#define IP_CMSG_RECVFRAGSIZE	BIT(8)



static inline bool sk_is_inet(struct sock *sk)

{

	return sk->sk_family == AF_INET || sk->sk_family == AF_INET6;

}



/**

 * sk_to_full_sk - Access to a full socket

 * @sk: pointer to a socket

net/core/skmsg.c

+5 −0
Original line number Diff line number Diff line
@@ -699,6 +699,11 @@ struct sk_psock *sk_psock_init(struct sock *sk, int node) 


	write_lock_bh(&sk->sk_callback_lock);



	if (sk_is_inet(sk) && inet_csk_has_ulp(sk)) {

		psock = ERR_PTR(-EINVAL);

		goto out;

	}



	if (sk->sk_user_data) {

		psock = ERR_PTR(-EBUSY);

		goto out;

net/ipv4/tcp_bpf.c

+0 −3
Original line number Diff line number Diff line
@@ -611,9 +611,6 @@ int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) 
		return 0;

	}



	if (inet_csk_has_ulp(sk))

		return -EINVAL;



	if (sk->sk_family == AF_INET6) {

		if (tcp_bpf_assert_proto_ops(psock->sk_proto))

			return -EINVAL;

net/tls/tls_main.c

+2 −0
Original line number Diff line number Diff line
@@ -921,6 +921,8 @@ static void tls_update(struct sock *sk, struct proto *p, 
{

	struct tls_context *ctx;



	WARN_ON_ONCE(sk->sk_prot == p);



	ctx = tls_get_ctx(sk);

	if (likely(ctx)) {

		ctx->sk_write_space = write_space;