[bpf PATCH 0/3] sockmap/ktls fixes

[bpf PATCH 0/3] sockmap/ktls fixes

[John Fastabend]

Series of fixes for sockmap and ktls, see patches for descriptions.

---

John Fastabend (3):
      bpf: tls, implement unhash to avoid transition out of ESTABLISHED
      bpf: sockmap remove duplicate queue free
      bpf: sockmap fix msg->sg.size account on ingress skb


 include/net/tls.h  |   14 ++++++++++++-
 net/core/skmsg.c   |    1 +
 net/ipv4/tcp_bpf.c |    2 --
 net/tls/tls_main.c |   57 ++++++++++++++++++++++++++++++++++++++--------------
 net/tls/tls_sw.c   |   13 ++++++++----
 5 files changed, 65 insertions(+), 22 deletions(-)

--
Signature

[bpf PATCH 1/3] bpf: tls, implement unhash to avoid transition out of ESTABLISHED

[John Fastabend]

It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE
state via tcp_disconnect() without calling into close callback. This
would allow a kTLS enabled socket to exist outside of ESTABLISHED
state which is not supported.

Solve this the same way we solved the sock{map|hash} case by adding
an unhash hook to remove tear down the TLS state.

In the process we also make the close hook more robust. We add a put
call into the close path, also in the unhash path, to remove the
reference to ulp data after free. Its no longer valid and may confuse
things later if the socket (re)enters kTLS code paths. Second we add
an 'if(ctx)' check to ensure the ctx is still valid and not released
from a previous unhash/close path.

Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 include/net/tls.h  |   14 ++++++++++++-
 net/tls/tls_main.c |   57 ++++++++++++++++++++++++++++++++++++++--------------
 net/tls/tls_sw.c   |   13 ++++++++----
 3 files changed, 64 insertions(+), 20 deletions(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index d9d0ac66f040..ae13ea19b375 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -266,6 +266,8 @@ struct tls_context {
 	void (*sk_write_space)(struct sock *sk);
 	void (*sk_destruct)(struct sock *sk);
 	void (*sk_proto_close)(struct sock *sk, long timeout);
+	void (*sk_proto_unhash)(struct sock *sk);
+	struct proto *sk_proto;
 
 	int  (*setsockopt)(struct sock *sk, int level,
 			   int optname, char __user *optval,
@@ -303,7 +305,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
 int tls_sw_sendpage(struct sock *sk, struct page *page,
 		    int offset, size_t size, int flags);
 void tls_sw_close(struct sock *sk, long timeout);
-void tls_sw_free_resources_tx(struct sock *sk);
+void tls_sw_free_resources_tx(struct sock *sk, bool locked);
 void tls_sw_free_resources_rx(struct sock *sk);
 void tls_sw_release_resources_rx(struct sock *sk);
 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
@@ -504,6 +506,16 @@ static inline void xor_iv_with_seq(int version, char *iv, char *seq)
 	}
 }
 
+static inline void tls_put_ctx(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tls_context *ctx = icsk->icsk_ulp_data;
+
+	if (!ctx)
+		return;
+	sk->sk_prot = ctx->sk_proto;
+	icsk->icsk_ulp_data = NULL;
+}
 
 static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
 		const struct tls_context *tls_ctx)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 7e546b8ec000..2973048957bd 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -261,23 +261,16 @@ static void tls_ctx_free(struct tls_context *ctx)
 	kfree(ctx);
 }
 
-static void tls_sk_proto_close(struct sock *sk, long timeout)
+static bool tls_sk_proto_destroy(struct sock *sk,
+				 struct tls_context *ctx, bool destroy)
 {
-	struct tls_context *ctx = tls_get_ctx(sk);
 	long timeo = sock_sndtimeo(sk, 0);
-	void (*sk_proto_close)(struct sock *sk, long timeout);
-	bool free_ctx = false;
-
-	lock_sock(sk);
-	sk_proto_close = ctx->sk_proto_close;
 
 	if (ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD)
-		goto skip_tx_cleanup;
+		return false;
 
-	if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) {
-		free_ctx = true;
-		goto skip_tx_cleanup;
-	}
+	if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE)
+		return true;
 
 	if (!tls_complete_pending_work(sk, ctx, 0, &timeo))
 		tls_handle_open_record(sk, 0);
@@ -286,10 +279,10 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
 	if (ctx->tx_conf == TLS_SW) {
 		kfree(ctx->tx.rec_seq);
 		kfree(ctx->tx.iv);
-		tls_sw_free_resources_tx(sk);
+		tls_sw_free_resources_tx(sk, destroy);
 #ifdef CONFIG_TLS_DEVICE
 	} else if (ctx->tx_conf == TLS_HW) {
-		tls_device_free_resources_tx(sk);
+		tls_device_free_resources_tx(sk, destroy);
 #endif
 	}
 
@@ -310,8 +303,39 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
 		tls_ctx_free(ctx);
 		ctx = NULL;
 	}
+	return false;
+}
+
+static void tls_sk_proto_unhash(struct sock *sk)
+{
+	struct tls_context *ctx = tls_get_ctx(sk);
+	void (*sk_proto_unhash)(struct sock *sk);
+	bool free_ctx;
+
+	if (!ctx)
+		return sk->sk_prot->unhash(sk);
+	sk_proto_unhash = ctx->sk_proto_unhash;
+	free_ctx = tls_sk_proto_destroy(sk, ctx, false);
+	tls_put_ctx(sk);
+	if (sk_proto_unhash)
+		sk_proto_unhash(sk);
+	if (free_ctx)
+		tls_ctx_free(ctx);
+}
 
-skip_tx_cleanup:
+static void tls_sk_proto_close(struct sock *sk, long timeout)
+{
+	struct tls_context *ctx = tls_get_ctx(sk);
+	void (*sk_proto_close)(struct sock *sk, long timeout);
+	bool free_ctx;
+
+	if (!ctx)
+		return sk->sk_prot->destroy(sk);
+
+	lock_sock(sk);
+	sk_proto_close = ctx->sk_proto_close;
+	free_ctx = tls_sk_proto_destroy(sk, ctx, true);
+	tls_put_ctx(sk);
 	release_sock(sk);
 	sk_proto_close(sk, timeout);
 	/* free ctx for TLS_HW_RECORD, used by tcp_set_state
@@ -609,6 +633,8 @@ static struct tls_context *create_ctx(struct sock *sk)
 	ctx->setsockopt = sk->sk_prot->setsockopt;
 	ctx->getsockopt = sk->sk_prot->getsockopt;
 	ctx->sk_proto_close = sk->sk_prot->close;
+	ctx->sk_proto_unhash = sk->sk_prot->unhash;
+	ctx->sk_proto = sk->sk_prot;
 	return ctx;
 }
 
@@ -732,6 +758,7 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
 	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
 	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
 	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
+	prot[TLS_BASE][TLS_BASE].unhash		= tls_sk_proto_unhash;
 
 	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
 	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index f780b473827b..0577633c319b 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2044,7 +2044,7 @@ static void tls_data_ready(struct sock *sk)
 	}
 }
 
-void tls_sw_free_resources_tx(struct sock *sk)
+void tls_sw_free_resources_tx(struct sock *sk, bool locked)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
@@ -2055,9 +2055,11 @@ void tls_sw_free_resources_tx(struct sock *sk)
 	if (atomic_read(&ctx->encrypt_pending))
 		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
 
-	release_sock(sk);
+	if (locked)
+		release_sock(sk);
 	cancel_delayed_work_sync(&ctx->tx_work.work);
-	lock_sock(sk);
+	if (locked)
+		lock_sock(sk);
 
 	/* Tx whatever records we can transmit and abandon the rest */
 	tls_tx_records(sk, -1);
@@ -2080,7 +2082,10 @@ void tls_sw_free_resources_tx(struct sock *sk)
 		kfree(rec);
 	}
 
-	crypto_free_aead(ctx->aead_send);
+	if (ctx->aead_send) {
+		crypto_free_aead(ctx->aead_send);
+		ctx->aead_send = NULL;
+	}
 	tls_free_open_rec(sk);
 
 	kfree(ctx);

[bpf PATCH 2/3] bpf: sockmap remove duplicate queue free

[John Fastabend]

In tcp bpf remove we free the cork list and purge the ingress msg
list. However we do this before the ref count reaches zero so it
could be possible some other access is in progress. In this case
(tcp close and/or tcp_unhash) we happen to also hold the sock
lock so no path exists but lets fix it otherwise it is extremely
fragile and breaks the reference counting rules. Also we already
check the cork list and ingress msg queue and free them once the
ref count reaches zero so its wasteful to check twice.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 net/ipv4/tcp_bpf.c |    2 --
 1 file changed, 2 deletions(-)

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 1bb7321a256d..4a619c85daed 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -528,8 +528,6 @@ static void tcp_bpf_remove(struct sock *sk, struct sk_psock *psock)
 {
 	struct sk_psock_link *link;
 
-	sk_psock_cork_free(psock);
-	__sk_psock_purge_ingress_msg(psock);
 	while ((link = sk_psock_link_pop(psock))) {
 		sk_psock_unlink(sk, link);
 		sk_psock_free_link(link);

[bpf PATCH 3/3] bpf: sockmap fix msg->sg.size account on ingress skb

[John Fastabend]

When converting a skb to msg->sg we forget to set the size after the
latest ktls/tls code conversion. This patch can be reached by doing
a redir into ingress path from BPF skb sock recv hook. Then trying to
read the size fails.

Fix this by setting the size.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 net/core/skmsg.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index cc94d921476c..782ae9eb4dce 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -411,6 +411,7 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
 	sk_mem_charge(sk, skb->len);
 	copied = skb->len;
 	msg->sg.start = 0;
+	msg->sg.size = copied;
 	msg->sg.end = num_sge == MAX_MSG_FRAGS ? 0 : num_sge;
 	msg->skb = skb;
 

Re: [bpf PATCH 1/3] bpf: tls, implement unhash to avoid transition out of ESTABLISHED

[Jakub Kicinski]

On Wed, 24 Apr 2019 12:21:03 -0700, John Fastabend wrote:
> It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE
> state via tcp_disconnect() without calling into close callback. This
> would allow a kTLS enabled socket to exist outside of ESTABLISHED
> state which is not supported.
> 
> Solve this the same way we solved the sock{map|hash} case by adding
> an unhash hook to remove tear down the TLS state.
> 
> In the process we also make the close hook more robust. We add a put
> call into the close path, also in the unhash path, to remove the
> reference to ulp data after free. Its no longer valid and may confuse
> things later if the socket (re)enters kTLS code paths. Second we add
> an 'if(ctx)' check to ensure the ctx is still valid and not released
> from a previous unhash/close path.
> 
> Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state")
> Reported-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

Nice, I think we were running into this!

Re: [bpf PATCH 1/3] bpf: tls, implement unhash to avoid transition out of ESTABLISHED

[Jakub Kicinski]

On Wed, 24 Apr 2019 12:21:03 -0700, John Fastabend wrote:
> It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE
> state via tcp_disconnect() without calling into close callback. This
> would allow a kTLS enabled socket to exist outside of ESTABLISHED
> state which is not supported.
> 
> Solve this the same way we solved the sock{map|hash} case by adding
> an unhash hook to remove tear down the TLS state.
> 
> In the process we also make the close hook more robust. We add a put
> call into the close path, also in the unhash path, to remove the
> reference to ulp data after free. Its no longer valid and may confuse
> things later if the socket (re)enters kTLS code paths. Second we add
> an 'if(ctx)' check to ensure the ctx is still valid and not released
> from a previous unhash/close path.
> 
> Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state")
> Reported-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: John Fastabend <john.fastabend@gmail.com>

Ah, EDOESNTBUILD, now I get to nitpick too? :)

> diff --git a/include/net/tls.h b/include/net/tls.h
> index d9d0ac66f040..ae13ea19b375 100644
> --- a/include/net/tls.h
> +++ b/include/net/tls.h
> @@ -266,6 +266,8 @@ struct tls_context {
>  	void (*sk_write_space)(struct sock *sk);
>  	void (*sk_destruct)(struct sock *sk);
>  	void (*sk_proto_close)(struct sock *sk, long timeout);
> +	void (*sk_proto_unhash)(struct sock *sk);
> +	struct proto *sk_proto;
>  
>  	int  (*setsockopt)(struct sock *sk, int level,
>  			   int optname, char __user *optval,
> @@ -303,7 +305,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
>  int tls_sw_sendpage(struct sock *sk, struct page *page,
>  		    int offset, size_t size, int flags);
>  void tls_sw_close(struct sock *sk, long timeout);
> -void tls_sw_free_resources_tx(struct sock *sk);
> +void tls_sw_free_resources_tx(struct sock *sk, bool locked);
>  void tls_sw_free_resources_rx(struct sock *sk);
>  void tls_sw_release_resources_rx(struct sock *sk);
>  int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
> @@ -504,6 +506,16 @@ static inline void xor_iv_with_seq(int version, char *iv, char *seq)
>  	}
>  }
>  
> +static inline void tls_put_ctx(struct sock *sk)
> +{
> +	struct inet_connection_sock *icsk = inet_csk(sk);
> +	struct tls_context *ctx = icsk->icsk_ulp_data;
> +
> +	if (!ctx)
> +		return;
> +	sk->sk_prot = ctx->sk_proto;
> +	icsk->icsk_ulp_data = NULL;
> +}
>  
>  static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
>  		const struct tls_context *tls_ctx)
> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
> index 7e546b8ec000..2973048957bd 100644
> --- a/net/tls/tls_main.c
> +++ b/net/tls/tls_main.c
> @@ -261,23 +261,16 @@ static void tls_ctx_free(struct tls_context *ctx)
>  	kfree(ctx);
>  }
>  
> -static void tls_sk_proto_close(struct sock *sk, long timeout)
> +static bool tls_sk_proto_destroy(struct sock *sk,
> +				 struct tls_context *ctx, bool destroy)

perhaps this destroy should rather be called locked?  It doesn't really
control destroying AFACT..

>  {
> -	struct tls_context *ctx = tls_get_ctx(sk);
>  	long timeo = sock_sndtimeo(sk, 0);
> -	void (*sk_proto_close)(struct sock *sk, long timeout);
> -	bool free_ctx = false;
> -
> -	lock_sock(sk);
> -	sk_proto_close = ctx->sk_proto_close;
>  
>  	if (ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD)
> -		goto skip_tx_cleanup;
> +		return false;
>  
> -	if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) {
> -		free_ctx = true;
> -		goto skip_tx_cleanup;
> -	}
> +	if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE)
> +		return true;
>  
>  	if (!tls_complete_pending_work(sk, ctx, 0, &timeo))
>  		tls_handle_open_record(sk, 0);
> @@ -286,10 +279,10 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
>  	if (ctx->tx_conf == TLS_SW) {
>  		kfree(ctx->tx.rec_seq);
>  		kfree(ctx->tx.iv);
> -		tls_sw_free_resources_tx(sk);
> +		tls_sw_free_resources_tx(sk, destroy);
>  #ifdef CONFIG_TLS_DEVICE
>  	} else if (ctx->tx_conf == TLS_HW) {
> -		tls_device_free_resources_tx(sk);
> +		tls_device_free_resources_tx(sk, destroy);

this part breaks the build tls_device_free_resources_tx() doesn't need
changes.  tls_device_offload_cleanup_rx() will though, cause it sleeps.

>  #endif
>  	}
>  
> @@ -310,8 +303,39 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
>  		tls_ctx_free(ctx);
>  		ctx = NULL;
>  	}
> +	return false;
> +}
> +
> +static void tls_sk_proto_unhash(struct sock *sk)
> +{
> +	struct tls_context *ctx = tls_get_ctx(sk);
> +	void (*sk_proto_unhash)(struct sock *sk);
> +	bool free_ctx;
> +
> +	if (!ctx)
> +		return sk->sk_prot->unhash(sk);
> +	sk_proto_unhash = ctx->sk_proto_unhash;
> +	free_ctx = tls_sk_proto_destroy(sk, ctx, false);
> +	tls_put_ctx(sk);
> +	if (sk_proto_unhash)
> +		sk_proto_unhash(sk);
> +	if (free_ctx)
> +		tls_ctx_free(ctx);
> +}
>  
> -skip_tx_cleanup:
> +static void tls_sk_proto_close(struct sock *sk, long timeout)
> +{
> +	struct tls_context *ctx = tls_get_ctx(sk);
> +	void (*sk_proto_close)(struct sock *sk, long timeout);

reverse xmas tree

> +	bool free_ctx;
> +
> +	if (!ctx)
> +		return sk->sk_prot->destroy(sk);
> +
> +	lock_sock(sk);
> +	sk_proto_close = ctx->sk_proto_close;
> +	free_ctx = tls_sk_proto_destroy(sk, ctx, true);
> +	tls_put_ctx(sk);
>  	release_sock(sk);
>  	sk_proto_close(sk, timeout);
>  	/* free ctx for TLS_HW_RECORD, used by tcp_set_state
> @@ -609,6 +633,8 @@ static struct tls_context *create_ctx(struct sock *sk)
>  	ctx->setsockopt = sk->sk_prot->setsockopt;
>  	ctx->getsockopt = sk->sk_prot->getsockopt;
>  	ctx->sk_proto_close = sk->sk_prot->close;
> +	ctx->sk_proto_unhash = sk->sk_prot->unhash;
> +	ctx->sk_proto = sk->sk_prot;
>  	return ctx;
>  }
>  
> @@ -732,6 +758,7 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG],
>  	prot[TLS_BASE][TLS_BASE].setsockopt	= tls_setsockopt;
>  	prot[TLS_BASE][TLS_BASE].getsockopt	= tls_getsockopt;
>  	prot[TLS_BASE][TLS_BASE].close		= tls_sk_proto_close;
> +	prot[TLS_BASE][TLS_BASE].unhash		= tls_sk_proto_unhash;
>  
>  	prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];
>  	prot[TLS_SW][TLS_BASE].sendmsg		= tls_sw_sendmsg;
> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
> index f780b473827b..0577633c319b 100644
> --- a/net/tls/tls_sw.c
> +++ b/net/tls/tls_sw.c
> @@ -2044,7 +2044,7 @@ static void tls_data_ready(struct sock *sk)
>  	}
>  }
>  
> -void tls_sw_free_resources_tx(struct sock *sk)
> +void tls_sw_free_resources_tx(struct sock *sk, bool locked)
>  {
>  	struct tls_context *tls_ctx = tls_get_ctx(sk);
>  	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
> @@ -2055,9 +2055,11 @@ void tls_sw_free_resources_tx(struct sock *sk)
>  	if (atomic_read(&ctx->encrypt_pending))
>  		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
>  
> -	release_sock(sk);
> +	if (locked)
> +		release_sock(sk);
>  	cancel_delayed_work_sync(&ctx->tx_work.work);
> -	lock_sock(sk);
> +	if (locked)
> +		lock_sock(sk);
>  
>  	/* Tx whatever records we can transmit and abandon the rest */
>  	tls_tx_records(sk, -1);
> @@ -2080,7 +2082,10 @@ void tls_sw_free_resources_tx(struct sock *sk)
>  		kfree(rec);
>  	}
>  
> -	crypto_free_aead(ctx->aead_send);
> +	if (ctx->aead_send) {
> +		crypto_free_aead(ctx->aead_send);
> +		ctx->aead_send = NULL;
> +	}
>  	tls_free_open_rec(sk);
>  
>  	kfree(ctx);
> 

Re: [bpf PATCH 1/3] bpf: tls, implement unhash to avoid transition out of ESTABLISHED

[John Fastabend]

On 4/24/19 8:07 PM, Jakub Kicinski wrote:
> On Wed, 24 Apr 2019 12:21:03 -0700, John Fastabend wrote:
>> It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE
>> state via tcp_disconnect() without calling into close callback. This
>> would allow a kTLS enabled socket to exist outside of ESTABLISHED
>> state which is not supported.
>>
>> Solve this the same way we solved the sock{map|hash} case by adding
>> an unhash hook to remove tear down the TLS state.
>>
>> In the process we also make the close hook more robust. We add a put
>> call into the close path, also in the unhash path, to remove the
>> reference to ulp data after free. Its no longer valid and may confuse
>> things later if the socket (re)enters kTLS code paths. Second we add
>> an 'if(ctx)' check to ensure the ctx is still valid and not released
>> from a previous unhash/close path.
>>
>> Fixes: d91c3e17f75f2 ("net/tls: Only attach to sockets in ESTABLISHED state")
>> Reported-by: Eric Dumazet <edumazet@google.com>
>> Signed-off-by: John Fastabend <john.fastabend@gmail.com>
> 
> Ah, EDOESNTBUILD, now I get to nitpick too? :)
> 

Oops messed up a merge conflict. nitpicks seems like a fair enough
punishment.

# CONFIG_TLS_DEVICE is not set


[...]

>>  static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
>>  		const struct tls_context *tls_ctx)
>> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
>> index 7e546b8ec000..2973048957bd 100644
>> --- a/net/tls/tls_main.c
>> +++ b/net/tls/tls_main.c
>> @@ -261,23 +261,16 @@ static void tls_ctx_free(struct tls_context *ctx)
>>  	kfree(ctx);
>>  }
>>  
>> -static void tls_sk_proto_close(struct sock *sk, long timeout)
>> +static bool tls_sk_proto_destroy(struct sock *sk,
>> +				 struct tls_context *ctx, bool destroy)
> 
> perhaps this destroy should rather be called locked?  It doesn't really
> control destroying AFACT..
> 

Sure we can call it locked.

>>  {
>> -	struct tls_context *ctx = tls_get_ctx(sk);
>>  	long timeo = sock_sndtimeo(sk, 0);
>> -	void (*sk_proto_close)(struct sock *sk, long timeout);
>> -	bool free_ctx = false;
>> -
>> -	lock_sock(sk);
>> -	sk_proto_close = ctx->sk_proto_close;
>>  
>>  	if (ctx->tx_conf == TLS_HW_RECORD && ctx->rx_conf == TLS_HW_RECORD)
>> -		goto skip_tx_cleanup;
>> +		return false;
>>  
>> -	if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE) {
>> -		free_ctx = true;
>> -		goto skip_tx_cleanup;
>> -	}
>> +	if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE)
>> +		return true;
>>  
>>  	if (!tls_complete_pending_work(sk, ctx, 0, &timeo))
>>  		tls_handle_open_record(sk, 0);
>> @@ -286,10 +279,10 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
>>  	if (ctx->tx_conf == TLS_SW) {
>>  		kfree(ctx->tx.rec_seq);
>>  		kfree(ctx->tx.iv);
>> -		tls_sw_free_resources_tx(sk);
>> +		tls_sw_free_resources_tx(sk, destroy);
>>  #ifdef CONFIG_TLS_DEVICE
>>  	} else if (ctx->tx_conf == TLS_HW) {
>> -		tls_device_free_resources_tx(sk);
>> +		tls_device_free_resources_tx(sk, destroy);
> 
> this part breaks the build tls_device_free_resources_tx() doesn't need
> changes.  tls_device_offload_cleanup_rx() will though, cause it sleeps.

OK will touch that path as well.

> 
>>  #endif
>>  	}
>>  
>> @@ -310,8 +303,39 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
>>  		tls_ctx_free(ctx);
>>  		ctx = NULL;
>>  	}
>> +	return false;
>> +}
>> +
>> +static void tls_sk_proto_unhash(struct sock *sk)
>> +{
>> +	struct tls_context *ctx = tls_get_ctx(sk);
>> +	void (*sk_proto_unhash)(struct sock *sk);
>> +	bool free_ctx;
>> +
>> +	if (!ctx)
>> +		return sk->sk_prot->unhash(sk);
>> +	sk_proto_unhash = ctx->sk_proto_unhash;
>> +	free_ctx = tls_sk_proto_destroy(sk, ctx, false);
>> +	tls_put_ctx(sk);
>> +	if (sk_proto_unhash)
>> +		sk_proto_unhash(sk);
>> +	if (free_ctx)
>> +		tls_ctx_free(ctx);
>> +}
>>  
>> -skip_tx_cleanup:
>> +static void tls_sk_proto_close(struct sock *sk, long timeout)
>> +{
>> +	struct tls_context *ctx = tls_get_ctx(sk);
>> +	void (*sk_proto_close)(struct sock *sk, long timeout);
> 
> reverse xmas tree
> 

+1

>> +	bool free_ctx;
>> +
>> +	if (!ctx)
>> +		return sk->sk_prot->destroy(sk);
>> +
>> +	lock_sock(sk);
>> +	sk_proto_close = ctx->sk_proto_close;
>> +	free_ctx = tls_sk_proto_destroy(sk, ctx, true);
>> +	tls_put_ctx(sk);
>>  	release_sock(sk);
>>  	sk_proto_close(sk, timeout);
>>  	/* free ctx for TLS_HW_RECORD, used by tcp_set_state


Thanks for reviewing.

[bpf PATCH 2/3] bpf: sockmap remove duplicate queue free

[John Fastabend]

In tcp bpf remove we free the cork list and purge the ingress msg
list. However we do this before the ref count reaches zero so it
could be possible some other access is in progress. In this case
(tcp close and/or tcp_unhash) we happen to also hold the sock
lock so no path exists but lets fix it otherwise it is extremely
fragile and breaks the reference counting rules. Also we already
check the cork list and ingress msg queue and free them once the
ref count reaches zero so its wasteful to check twice.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 net/ipv4/tcp_bpf.c |    2 --
 1 file changed, 2 deletions(-)

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 1bb7321a256d..4a619c85daed 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -528,8 +528,6 @@ static void tcp_bpf_remove(struct sock *sk, struct sk_psock *psock)
 {
 	struct sk_psock_link *link;
 
-	sk_psock_cork_free(psock);
-	__sk_psock_purge_ingress_msg(psock);
 	while ((link = sk_psock_link_pop(psock))) {
 		sk_psock_unlink(sk, link);
 		sk_psock_free_link(link);