[bpf-next PATCH v3 0/4] sockmap/ktls fixes

[bpf-next PATCH v3 0/4] sockmap/ktls fixes

[John Fastabend]

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

v2: fix build issue for CONFIG_TLS_DEVICE and fixup couple comments
    from Jakub

v3: fix issue where release could call unhash resulting in a use after
    free. Now we detach the ulp pointer before calling into destroy
    or unhash. This way if we get a callback into unhash from destroy
    path there is no ulp to access. The fallout is we must pass the
    ctx into the functions rather than use the sk lookup in each
    routine. This is probably better anyways.

    @Jakub, I did not fix the hw device case it seems the ulp ptr is
    needed for the hardware teardown but this is buggy for sure. Its
    not clear to me how to resolve the hw issue at the moment so fix
    the sw path why we discuss it.

---

John Fastabend (4):
      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
      bpf: sockmap, only stop/flush strp if it was enabled at some point


 include/net/tls.h    |   24 ++++++++++++---
 net/core/skmsg.c     |    7 +++-
 net/ipv4/tcp_bpf.c   |    2 -
 net/tls/tls_device.c |    6 ++--
 net/tls/tls_main.c   |   78 +++++++++++++++++++++++++++++++++-----------------
 net/tls/tls_sw.c     |   51 ++++++++++++++++-----------------
 6 files changed, 103 insertions(+), 65 deletions(-)

--
Signature

[bpf-next PATCH v3 1/4] 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 Its no longer valid and may confuse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    |   24 ++++++++++++---
 net/tls/tls_device.c |    6 ++--
 net/tls/tls_main.c   |   78 +++++++++++++++++++++++++++++++++-----------------
 net/tls/tls_sw.c     |   51 ++++++++++++++++-----------------
 4 files changed, 98 insertions(+), 61 deletions(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index d9d0ac66f040..0782a92487f1 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -261,11 +261,14 @@ struct tls_context {
 	bool in_tcp_sendpages;
 	bool pending_open_record_frags;
 
-	int (*push_pending_record)(struct sock *sk, int flags);
+	int (*push_pending_record)(struct sock *sk,
+				   struct tls_context *ctx, int flags);
 
 	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,
@@ -303,9 +306,10 @@ 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_rx(struct sock *sk);
-void tls_sw_release_resources_rx(struct sock *sk);
+void tls_sw_free_resources_tx(struct sock *sk,
+			      struct tls_context *ctx, bool locked);
+void tls_sw_free_resources_rx(struct sock *sk, struct tls_context *ctx);
+void tls_sw_release_resources_rx(struct sock *sk, struct tls_context *ctx);
 int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 		   int nonblock, int flags, int *addr_len);
 bool tls_sw_stream_read(const struct sock *sk);
@@ -321,7 +325,7 @@ void tls_device_sk_destruct(struct sock *sk);
 void tls_device_free_resources_tx(struct sock *sk);
 void tls_device_init(void);
 void tls_device_cleanup(void);
-int tls_tx_records(struct sock *sk, int flags);
+int tls_tx_records(struct sock *sk, struct tls_context *ctx, int flags);
 
 struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 				       u32 seq, u64 *p_record_sn);
@@ -504,6 +508,16 @@ 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_device.c b/net/tls/tls_device.c
index 9f3bdbc1e593..702a024c0c7b 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -548,7 +548,7 @@ struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 }
 EXPORT_SYMBOL(tls_get_record);
 
-static int tls_device_push_pending_record(struct sock *sk, int flags)
+static int tls_device_push_pending_record(struct sock *sk, struct tls_context *ctx, int flags)
 {
 	struct iov_iter	msg_iter;
 
@@ -904,7 +904,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 	goto release_netdev;
 
 free_sw_resources:
-	tls_sw_free_resources_rx(sk);
+	tls_sw_free_resources_rx(sk, ctx);
 release_ctx:
 	ctx->priv_ctx_rx = NULL;
 release_netdev:
@@ -941,7 +941,7 @@ void tls_device_offload_cleanup_rx(struct sock *sk)
 	up_read(&device_offload_lock);
 	kfree(tls_ctx->rx.rec_seq);
 	kfree(tls_ctx->rx.iv);
-	tls_sw_release_resources_rx(sk);
+	tls_sw_release_resources_rx(sk, tls_ctx);
 }
 
 static int tls_device_down(struct net_device *netdev)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 7e546b8ec000..de2ec8349361 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -150,12 +150,10 @@ int tls_push_sg(struct sock *sk,
 	return 0;
 }
 
-static int tls_handle_open_record(struct sock *sk, int flags)
+static int tls_handle_open_record(struct sock *sk, struct tls_context *ctx, int flags)
 {
-	struct tls_context *ctx = tls_get_ctx(sk);
-
 	if (tls_is_pending_open_record(ctx))
-		return ctx->push_pending_record(sk, flags);
+		return ctx->push_pending_record(sk, ctx, flags);
 
 	return 0;
 }
@@ -163,6 +161,7 @@ static int tls_handle_open_record(struct sock *sk, int flags)
 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 		      unsigned char *record_type)
 {
+	struct tls_context *ctx;
 	struct cmsghdr *cmsg;
 	int rc = -EINVAL;
 
@@ -180,7 +179,8 @@ int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 			if (msg->msg_flags & MSG_MORE)
 				return -EINVAL;
 
-			rc = tls_handle_open_record(sk, msg->msg_flags);
+			ctx = tls_get_ctx(sk);
+			rc = tls_handle_open_record(sk, ctx, msg->msg_flags);
 			if (rc)
 				return rc;
 
@@ -261,32 +261,28 @@ 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 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_HW && ctx->rx_conf != TLS_HW)
+		tls_put_ctx(sk);
+
+	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);
+		tls_handle_open_record(sk, ctx, 0);
 
 	/* We need these for tls_sw_fallback handling of other packets */
 	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, ctx, locked);
 #ifdef CONFIG_TLS_DEVICE
 	} else if (ctx->tx_conf == TLS_HW) {
 		tls_device_free_resources_tx(sk);
@@ -296,22 +292,47 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
 	if (ctx->rx_conf == TLS_SW) {
 		kfree(ctx->rx.rec_seq);
 		kfree(ctx->rx.iv);
-		tls_sw_free_resources_rx(sk);
+		tls_sw_free_resources_rx(sk, ctx);
 	}
 
 #ifdef CONFIG_TLS_DEVICE
 	if (ctx->rx_conf == TLS_HW)
 		tls_device_offload_cleanup_rx(sk);
-
-	if (ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW) {
-#else
-	{
 #endif
+
+	if (ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW)
+		return true;
+	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);
+	if (sk_proto_unhash)
+		sk_proto_unhash(sk);
+	if (free_ctx)
 		tls_ctx_free(ctx);
-		ctx = NULL;
-	}
+}
+
+static void tls_sk_proto_close(struct sock *sk, long timeout)
+{
+	void (*sk_proto_close)(struct sock *sk, long timeout);
+	struct tls_context *ctx = tls_get_ctx(sk);
+	bool free_ctx;
 
-skip_tx_cleanup:
+	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);
 	release_sock(sk);
 	sk_proto_close(sk, timeout);
 	/* free ctx for TLS_HW_RECORD, used by tcp_set_state
@@ -609,6 +630,8 @@ 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 +755,7 @@ 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..f145ab879552 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -337,9 +337,8 @@ static void tls_free_rec(struct sock *sk, struct tls_rec *rec)
 	kfree(rec);
 }
 
-static void tls_free_open_rec(struct sock *sk)
+static void tls_free_open_rec(struct sock *sk, struct tls_context *tls_ctx)
 {
-	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
 	struct tls_rec *rec = ctx->open_rec;
 
@@ -349,9 +348,8 @@ static void tls_free_open_rec(struct sock *sk)
 	}
 }
 
-int tls_tx_records(struct sock *sk, int flags)
+int tls_tx_records(struct sock *sk, struct tls_context *tls_ctx, int flags)
 {
-	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
 	struct tls_rec *rec, *tmp;
 	struct sk_msg *msg_en;
@@ -737,7 +735,7 @@ static int tls_push_record(struct sock *sk, int flags,
 		ctx->open_rec = tmp;
 	}
 
-	return tls_tx_records(sk, flags);
+	return tls_tx_records(sk, tls_ctx, flags);
 }
 
 static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
@@ -783,7 +781,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 		err = tls_push_record(sk, flags, record_type);
 		if (err < 0) {
 			*copied -= sk_msg_free(sk, msg);
-			tls_free_open_rec(sk);
+			tls_free_open_rec(sk, tls_ctx);
 			goto out_err;
 		}
 		break;
@@ -804,7 +802,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 			msg->sg.size = 0;
 		}
 		if (msg->sg.size == 0)
-			tls_free_open_rec(sk);
+			tls_free_open_rec(sk, tls_ctx);
 		break;
 	case __SK_DROP:
 	default:
@@ -814,7 +812,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 		else
 			msg->apply_bytes -= send;
 		if (msg->sg.size == 0)
-			tls_free_open_rec(sk);
+			tls_free_open_rec(sk, tls_ctx);
 		*copied -= (send + delta);
 		err = -EACCES;
 	}
@@ -843,9 +841,9 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 	return err;
 }
 
-static int tls_sw_push_pending_record(struct sock *sk, int flags)
+static int tls_sw_push_pending_record(struct sock *sk,
+				      struct tls_context *tls_ctx, int flags)
 {
-	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
 	struct tls_rec *rec = ctx->open_rec;
 	struct sk_msg *msg_pl;
@@ -1074,7 +1072,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 	/* Transmit if any encryptions have completed */
 	if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
 		cancel_delayed_work(&ctx->tx_work.work);
-		tls_tx_records(sk, msg->msg_flags);
+		tls_tx_records(sk, tls_ctx, msg->msg_flags);
 	}
 
 send_end:
@@ -1199,7 +1197,7 @@ static int tls_sw_do_sendpage(struct sock *sk, struct page *page,
 		/* Transmit if any encryptions have completed */
 		if (test_and_clear_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask)) {
 			cancel_delayed_work(&ctx->tx_work.work);
-			tls_tx_records(sk, flags);
+			tls_tx_records(sk, tls_ctx, flags);
 		}
 	}
 sendpage_end:
@@ -2044,9 +2042,8 @@ 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, struct tls_context *tls_ctx, bool locked)
 {
-	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
 	struct tls_rec *rec, *tmp;
 
@@ -2055,12 +2052,14 @@ 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);
+	tls_tx_records(sk, tls_ctx, -1);
 
 	/* Free up un-sent records in tx_list. First, free
 	 * the partially sent record if any at head of tx_list.
@@ -2080,15 +2079,17 @@ void tls_sw_free_resources_tx(struct sock *sk)
 		kfree(rec);
 	}
 
-	crypto_free_aead(ctx->aead_send);
-	tls_free_open_rec(sk);
+	if (ctx->aead_send) {
+		crypto_free_aead(ctx->aead_send);
+		ctx->aead_send = NULL;
+	}
+	tls_free_open_rec(sk, tls_ctx);
 
 	kfree(ctx);
 }
 
-void tls_sw_release_resources_rx(struct sock *sk)
+void tls_sw_release_resources_rx(struct sock *sk, struct tls_context *tls_ctx)
 {
-	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 
 	if (ctx->aead_recv) {
@@ -2106,13 +2107,11 @@ void tls_sw_release_resources_rx(struct sock *sk)
 	}
 }
 
-void tls_sw_free_resources_rx(struct sock *sk)
+void tls_sw_free_resources_rx(struct sock *sk, struct tls_context *tls_ctx)
 {
-	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 
-	tls_sw_release_resources_rx(sk);
-
+	tls_sw_release_resources_rx(sk, tls_ctx);
 	kfree(ctx);
 }
 
@@ -2130,7 +2129,7 @@ static void tx_work_handler(struct work_struct *work)
 		return;
 
 	lock_sock(sk);
-	tls_tx_records(sk, -1);
+	tls_tx_records(sk, tls_ctx, -1);
 	release_sock(sk);
 }
 

[bpf-next PATCH v3 2/4] 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-next PATCH v3 3/4] 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;
 

[bpf-next PATCH v3 4/4] bpf: sockmap, only stop/flush strp if it was enabled at some point

[John Fastabend]

If we try to call strp_done on a parser that has never been
initialized, because the sockmap user is only using TX side for
example we get the following error.


  [  883.422081] WARNING: CPU: 1 PID: 208 at kernel/workqueue.c:3030 __flush_work+0x1ca/0x1e0
  ...
  [  883.422095] Workqueue: events sk_psock_destroy_deferred
  [  883.422097] RIP: 0010:__flush_work+0x1ca/0x1e0


This had been wrapped in a 'if (psock->parser.enabled)' logic which
was broken because the strp_done() was never actually being called
because we do a strp_stop() earlier in the tear down logic will
set parser.enabled to false. This could result in a use after free
if work was still in the queue and was resolved by the patch here,
1d79895aef18f ("sk_msg: Always cancel strp work before freeing the
psock"). However, calling strp_stop(), done by the patch marked in
the fixes tag, only is useful if we never initialized a strp parser
program and never initialized the strp to start with. Because if
we had initialized a stream parser strp_stop() would have been called
by sk_psock_drop() earlier in the tear down process.  By forcing the
strp to stop we get past the WARNING in strp_done that checks
the stopped flag but calling cancel_work_sync on work that has never
been initialized is also wrong and generates the warning above.

To fix check if the parser program exists. If the program exists
then the strp work has been initialized and must be sync'd and
cancelled before free'ing any structures. If no program exists we
never initialized the stream parser in the first place so skip the
sync/cancel logic implemented by strp_done.

Finally, remove the strp_done its not needed and in the case where we are using the
stream parser has already been called.

Fixes: e8e3437762ad9 ("bpf: Stop the psock parser before canceling its work")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
 net/core/skmsg.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 782ae9eb4dce..93bffaad2135 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -555,8 +555,10 @@ static void sk_psock_destroy_deferred(struct work_struct *gc)
 	struct sk_psock *psock = container_of(gc, struct sk_psock, gc);
 
 	/* No sk_callback_lock since already detached. */
-	strp_stop(&psock->parser.strp);
-	strp_done(&psock->parser.strp);
+
+	/* Parser has been stopped */
+	if (psock->progs.skb_parser)
+		strp_done(&psock->parser.strp);
 
 	cancel_work_sync(&psock->work);
 

Re: [bpf-next PATCH v3 0/4] sockmap/ktls fixes

[John Fastabend]

On 4/30/19 7:06 PM, John Fastabend wrote:
> Series of fixes for sockmap and ktls, see patches for descriptions.
> 
> v2: fix build issue for CONFIG_TLS_DEVICE and fixup couple comments
>     from Jakub
> 
> v3: fix issue where release could call unhash resulting in a use after
>     free. Now we detach the ulp pointer before calling into destroy
>     or unhash. This way if we get a callback into unhash from destroy
>     path there is no ulp to access. The fallout is we must pass the
>     ctx into the functions rather than use the sk lookup in each
>     routine. This is probably better anyways.
> 
>     @Jakub, I did not fix the hw device case it seems the ulp ptr is
>     needed for the hardware teardown but this is buggy for sure. Its
>     not clear to me how to resolve the hw issue at the moment so fix
>     the sw path why we discuss it.
> 
Unfortunately, this is still failing with hardware offload (thanks
Jakub) so will need a v4 to actually fix this.


Thanks,
John

> ---
> 
> John Fastabend (4):
>       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
>       bpf: sockmap, only stop/flush strp if it was enabled at some point
> 
> 
>  include/net/tls.h    |   24 ++++++++++++---
>  net/core/skmsg.c     |    7 +++-
>  net/ipv4/tcp_bpf.c   |    2 -
>  net/tls/tls_device.c |    6 ++--
>  net/tls/tls_main.c   |   78 +++++++++++++++++++++++++++++++++-----------------
>  net/tls/tls_sw.c     |   51 ++++++++++++++++-----------------
>  6 files changed, 103 insertions(+), 65 deletions(-)
> 
> --
> Signature
> 

Re: [bpf-next PATCH v3 0/4] sockmap/ktls fixes

[Daniel Borkmann]

On 05/02/2019 10:05 PM, John Fastabend wrote:
> On 4/30/19 7:06 PM, John Fastabend wrote:
>> Series of fixes for sockmap and ktls, see patches for descriptions.
>>
>> v2: fix build issue for CONFIG_TLS_DEVICE and fixup couple comments
>>     from Jakub
>>
>> v3: fix issue where release could call unhash resulting in a use after
>>     free. Now we detach the ulp pointer before calling into destroy
>>     or unhash. This way if we get a callback into unhash from destroy
>>     path there is no ulp to access. The fallout is we must pass the
>>     ctx into the functions rather than use the sk lookup in each
>>     routine. This is probably better anyways.
>>
>>     @Jakub, I did not fix the hw device case it seems the ulp ptr is
>>     needed for the hardware teardown but this is buggy for sure. Its
>>     not clear to me how to resolve the hw issue at the moment so fix
>>     the sw path why we discuss it.
>>
> Unfortunately, this is still failing with hardware offload (thanks
> Jakub) so will need a v4 to actually fix this.

Perhaps split off the skmsg fixes from the series so they can already
be applied since they should be independent of the tlx fix?

Thanks,
Daniel