net/tls: use RCU protection on icsk->icsk_ulp_data

We need to make sure context does not get freed while diag
code is interrogating it. Free struct tls_context with
kfree_rcu().

We add the __rcu annotation directly in icsk, and cast it
away in the datapath accessor. Presumably all ULPs will
do a similar thing.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2019-08-30 12:25:47 +02:00 committed by David S. Miller
parent ed6e8103ba
commit 15a7dea750
5 changed files with 29 additions and 12 deletions

View file

@ -251,14 +251,26 @@ static void tls_write_space(struct sock *sk)
ctx->sk_write_space(sk);
}
void tls_ctx_free(struct tls_context *ctx)
/**
* tls_ctx_free() - free TLS ULP context
* @sk: socket to with @ctx is attached
* @ctx: TLS context structure
*
* Free TLS context. If @sk is %NULL caller guarantees that the socket
* to which @ctx was attached has no outstanding references.
*/
void tls_ctx_free(struct sock *sk, struct tls_context *ctx)
{
if (!ctx)
return;
memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
kfree(ctx);
if (sk)
kfree_rcu(ctx, rcu);
else
kfree(ctx);
}
static void tls_sk_proto_cleanup(struct sock *sk,
@ -306,7 +318,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
write_lock_bh(&sk->sk_callback_lock);
if (free_ctx)
icsk->icsk_ulp_data = NULL;
rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
sk->sk_prot = ctx->sk_proto;
if (sk->sk_write_space == tls_write_space)
sk->sk_write_space = ctx->sk_write_space;
@ -321,7 +333,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
ctx->sk_proto_close(sk, timeout);
if (free_ctx)
tls_ctx_free(ctx);
tls_ctx_free(sk, ctx);
}
static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
@ -610,7 +622,7 @@ static struct tls_context *create_ctx(struct sock *sk)
if (!ctx)
return NULL;
icsk->icsk_ulp_data = ctx;
rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
ctx->setsockopt = sk->sk_prot->setsockopt;
ctx->getsockopt = sk->sk_prot->getsockopt;
ctx->sk_proto_close = sk->sk_prot->close;
@ -651,8 +663,8 @@ static void tls_hw_sk_destruct(struct sock *sk)
ctx->sk_destruct(sk);
/* Free ctx */
tls_ctx_free(ctx);
icsk->icsk_ulp_data = NULL;
rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
tls_ctx_free(sk, ctx);
}
static int tls_hw_prot(struct sock *sk)