[PATCH net 0/5] rxrpc: Miscellaneous fixes

[PATCH net 0/5] rxrpc: Miscellaneous fixes

[David Howells]

Here are some fixes for rxrpc:

 (1) Fix the calling of IP routing code with IRQs disabled.

 (2) Fix a recvmsg/recvmsg race when the first completes a call.

 (3) Fix a race between notification, recvmsg and sendmsg releasing a call.

 (4) Fix abort of abort.

 (5) Fix call-level aborts that should be connection-level aborts.

David

The patches can be found here also:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-fixes

David Howells (5):
  rxrpc: Fix irq-disabled in local_bh_enable()
  rxrpc: Fix recv-recv race of completed call
  rxrpc: Fix notification vs call-release vs recvmsg
  rxrpc: Fix transmission of an abort in response to an abort
  rxrpc: Fix to use conn aborts for conn-wide failures

 include/trace/events/rxrpc.h |  6 +++++-
 net/rxrpc/ar-internal.h      |  4 ++++
 net/rxrpc/call_accept.c      | 14 ++++++++------
 net/rxrpc/call_object.c      | 28 ++++++++++++----------------
 net/rxrpc/io_thread.c        | 14 ++++++++++++++
 net/rxrpc/output.c           | 22 +++++++++++++---------
 net/rxrpc/peer_object.c      |  6 ++----
 net/rxrpc/recvmsg.c          | 23 +++++++++++++++++++++--
 net/rxrpc/security.c         |  8 ++++----
 9 files changed, 83 insertions(+), 42 deletions(-)

[PATCH net 1/5] rxrpc: Fix irq-disabled in local_bh_enable()

[David Howells]

The rxrpc_assess_MTU_size() function calls down into the IP layer to find
out the MTU size for a route.  When accepting an incoming call, this is
called from rxrpc_new_incoming_call() which holds interrupts disabled
across the code that calls down to it.  Unfortunately, the IP layer uses
local_bh_enable() which, config dependent, throws a warning if IRQs are
enabled:

WARNING: CPU: 1 PID: 5544 at kernel/softirq.c:387 __local_bh_enable_ip+0x43/0xd0
...
RIP: 0010:__local_bh_enable_ip+0x43/0xd0
...
Call Trace:
 <TASK>
 rt_cache_route+0x7e/0xa0
 rt_set_nexthop.isra.0+0x3b3/0x3f0
 __mkroute_output+0x43a/0x460
 ip_route_output_key_hash+0xf7/0x140
 ip_route_output_flow+0x1b/0x90
 rxrpc_assess_MTU_size.isra.0+0x2a0/0x590
 rxrpc_new_incoming_peer+0x46/0x120
 rxrpc_alloc_incoming_call+0x1b1/0x400
 rxrpc_new_incoming_call+0x1da/0x5e0
 rxrpc_input_packet+0x827/0x900
 rxrpc_io_thread+0x403/0xb60
 kthread+0x2f7/0x310
 ret_from_fork+0x2a/0x230
 ret_from_fork_asm+0x1a/0x30
...
hardirqs last  enabled at (23): _raw_spin_unlock_irq+0x24/0x50
hardirqs last disabled at (24): _raw_read_lock_irq+0x17/0x70
softirqs last  enabled at (0): copy_process+0xc61/0x2730
softirqs last disabled at (25): rt_add_uncached_list+0x3c/0x90

Fix this by moving the call to rxrpc_assess_MTU_size() out of
rxrpc_init_peer() and further up the stack where it can be done without
interrupts disabled.

It shouldn't be a problem for rxrpc_new_incoming_call() to do it after the
locks are dropped as pmtud is going to be performed by the I/O thread - and
we're in the I/O thread at this point.

Fixes: a2ea9a907260 ("rxrpc: Use irq-disabling spinlocks between app and I/O thread")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
cc: stable@vger.kernel.org
---
 net/rxrpc/ar-internal.h | 1 +
 net/rxrpc/call_accept.c | 1 +
 net/rxrpc/peer_object.c | 6 ++----
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 376e33dce8c1..df1a618dbf7d 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -1383,6 +1383,7 @@ struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *,
 					 const struct sockaddr_rxrpc *);
 struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *local,
 				     struct sockaddr_rxrpc *srx, gfp_t gfp);
+void rxrpc_assess_MTU_size(struct rxrpc_local *local, struct rxrpc_peer *peer);
 struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *, gfp_t,
 				    enum rxrpc_peer_trace);
 void rxrpc_new_incoming_peer(struct rxrpc_local *local, struct rxrpc_peer *peer);
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 49fccee1a726..226b4bf82747 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -406,6 +406,7 @@ bool rxrpc_new_incoming_call(struct rxrpc_local *local,
 
 	spin_unlock(&rx->incoming_lock);
 	read_unlock_irq(&local->services_lock);
+	rxrpc_assess_MTU_size(local, call->peer);
 
 	if (hlist_unhashed(&call->error_link)) {
 		spin_lock_irq(&call->peer->lock);
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
index e2f35e6c04d6..366431b0736c 100644
--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -149,8 +149,7 @@ struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
  * assess the MTU size for the network interface through which this peer is
  * reached
  */
-static void rxrpc_assess_MTU_size(struct rxrpc_local *local,
-				  struct rxrpc_peer *peer)
+void rxrpc_assess_MTU_size(struct rxrpc_local *local, struct rxrpc_peer *peer)
 {
 	struct net *net = local->net;
 	struct dst_entry *dst;
@@ -277,8 +276,6 @@ static void rxrpc_init_peer(struct rxrpc_local *local, struct rxrpc_peer *peer,
 
 	peer->hdrsize += sizeof(struct rxrpc_wire_header);
 	peer->max_data = peer->if_mtu - peer->hdrsize;
-
-	rxrpc_assess_MTU_size(local, peer);
 }
 
 /*
@@ -297,6 +294,7 @@ static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_local *local,
 	if (peer) {
 		memcpy(&peer->srx, srx, sizeof(*srx));
 		rxrpc_init_peer(local, peer, hash_key);
+		rxrpc_assess_MTU_size(local, peer);
 	}
 
 	_leave(" = %p", peer);

[PATCH net 2/5] rxrpc: Fix recv-recv race of completed call

[David Howells]

If a call receives an event (such as incoming data), the call gets placed
on the socket's queue and a thread in recvmsg can be awakened to go and
process it.  Once the thread has picked up the call off of the queue,
further events will cause it to be requeued, and once the socket lock is
dropped (recvmsg uses call->user_mutex to allow the socket to be used in
parallel), a second thread can come in and its recvmsg can pop the call off
the socket queue again.

In such a case, the first thread will be receiving stuff from the call and
the second thread will be blocked on call->user_mutex.  The first thread
can, at this point, process both the event that it picked call for and the
event that the second thread picked the call for and may see the call
terminate - in which case the call will be "released", decoupling the call
from the user call ID assigned to it (RXRPC_USER_CALL_ID in the control
message).

The first thread will return okay, but then the second thread will wake up
holding the user_mutex and, if it sees that the call has been released by
the first thread, it will BUG thusly:

	kernel BUG at net/rxrpc/recvmsg.c:474!

Fix this by just dequeuing the call and ignoring it if it is seen to be
already released.  We can't tell userspace about it anyway as the user call
ID has become stale.

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
cc: stable@vger.kernel.org
---
 include/trace/events/rxrpc.h |  3 +++
 net/rxrpc/call_accept.c      |  1 +
 net/rxrpc/recvmsg.c          | 19 +++++++++++++++++--
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 378d2dfc7392..e7dcfb1369b6 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -330,12 +330,15 @@
 	EM(rxrpc_call_put_userid,		"PUT user-id ") \
 	EM(rxrpc_call_see_accept,		"SEE accept  ") \
 	EM(rxrpc_call_see_activate_client,	"SEE act-clnt") \
+	EM(rxrpc_call_see_already_released,	"SEE alrdy-rl") \
 	EM(rxrpc_call_see_connect_failed,	"SEE con-fail") \
 	EM(rxrpc_call_see_connected,		"SEE connect ") \
 	EM(rxrpc_call_see_conn_abort,		"SEE conn-abt") \
+	EM(rxrpc_call_see_discard,		"SEE discard ") \
 	EM(rxrpc_call_see_disconnected,		"SEE disconn ") \
 	EM(rxrpc_call_see_distribute_error,	"SEE dist-err") \
 	EM(rxrpc_call_see_input,		"SEE input   ") \
+	EM(rxrpc_call_see_recvmsg,		"SEE recvmsg ") \
 	EM(rxrpc_call_see_release,		"SEE release ") \
 	EM(rxrpc_call_see_userid_exists,	"SEE u-exists") \
 	EM(rxrpc_call_see_waiting_call,		"SEE q-conn  ") \
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 226b4bf82747..a4d76f2da684 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -219,6 +219,7 @@ void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
 	tail = b->call_backlog_tail;
 	while (CIRC_CNT(head, tail, size) > 0) {
 		struct rxrpc_call *call = b->call_backlog[tail];
+		rxrpc_see_call(call, rxrpc_call_see_discard);
 		rcu_assign_pointer(call->socket, rx);
 		if (rx->app_ops &&
 		    rx->app_ops->discard_new_call) {
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 86a27fb55a1c..6990e37697de 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -447,6 +447,16 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 		goto try_again;
 	}
 
+	rxrpc_see_call(call, rxrpc_call_see_recvmsg);
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		rxrpc_see_call(call, rxrpc_call_see_already_released);
+		list_del_init(&call->recvmsg_link);
+		spin_unlock_irq(&rx->recvmsg_lock);
+		release_sock(&rx->sk);
+		trace_rxrpc_recvmsg(call->debug_id, rxrpc_recvmsg_unqueue, 0);
+		rxrpc_put_call(call, rxrpc_call_put_recvmsg);
+		goto try_again;
+	}
 	if (!(flags & MSG_PEEK))
 		list_del_init(&call->recvmsg_link);
 	else
@@ -470,8 +480,13 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 
 	release_sock(&rx->sk);
 
-	if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
-		BUG();
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		rxrpc_see_call(call, rxrpc_call_see_already_released);
+		mutex_unlock(&call->user_mutex);
+		if (!(flags & MSG_PEEK))
+			rxrpc_put_call(call, rxrpc_call_put_recvmsg);
+		goto try_again;
+	}
 
 	ret = rxrpc_recvmsg_user_id(call, msg, flags);
 	if (ret < 0)

[PATCH net 3/5] rxrpc: Fix notification vs call-release vs recvmsg

[David Howells]

When a call is released, rxrpc takes the spinlock and removes it from
->recvmsg_q in an effort to prevent racing recvmsg() invocations from
seeing the same call.  Now, rxrpc_recvmsg() only takes the spinlock when
actually removing a call from the queue; it doesn't, however, take it in
the lead up to that when it checks to see if the queue is empty.  It *does*
hold the socket lock, which prevents a recvmsg/recvmsg race - but this
doesn't prevent sendmsg from ending the call because sendmsg() drops the
socket lock and relies on the call->user_mutex.

Fix this by firstly removing the bit in rxrpc_release_call() that dequeues
the released call and, instead, rely on recvmsg() to simply discard
released calls (done in a preceding fix).

Secondly, rxrpc_notify_socket() is abandoned if the call is already marked
as released rather than trying to be clever by setting both pointers in
call->recvmsg_link to NULL to trick list_empty().  This isn't perfect and
can still race, resulting in a released call on the queue, but recvmsg()
will now clean that up.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
cc: stable@vger.kernel.org
---
 include/trace/events/rxrpc.h |  2 +-
 net/rxrpc/call_object.c      | 28 ++++++++++++----------------
 net/rxrpc/recvmsg.c          |  4 ++++
 3 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index e7dcfb1369b6..8e5a73eb5268 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -325,7 +325,6 @@
 	EM(rxrpc_call_put_release_sock,		"PUT rls-sock") \
 	EM(rxrpc_call_put_release_sock_tba,	"PUT rls-sk-a") \
 	EM(rxrpc_call_put_sendmsg,		"PUT sendmsg ") \
-	EM(rxrpc_call_put_unnotify,		"PUT unnotify") \
 	EM(rxrpc_call_put_userid_exists,	"PUT u-exists") \
 	EM(rxrpc_call_put_userid,		"PUT user-id ") \
 	EM(rxrpc_call_see_accept,		"SEE accept  ") \
@@ -338,6 +337,7 @@
 	EM(rxrpc_call_see_disconnected,		"SEE disconn ") \
 	EM(rxrpc_call_see_distribute_error,	"SEE dist-err") \
 	EM(rxrpc_call_see_input,		"SEE input   ") \
+	EM(rxrpc_call_see_notify_released,	"SEE nfy-rlsd") \
 	EM(rxrpc_call_see_recvmsg,		"SEE recvmsg ") \
 	EM(rxrpc_call_see_release,		"SEE release ") \
 	EM(rxrpc_call_see_userid_exists,	"SEE u-exists") \
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 15067ff7b1f2..918f41d97a2f 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -561,7 +561,7 @@ static void rxrpc_cleanup_rx_buffers(struct rxrpc_call *call)
 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 {
 	struct rxrpc_connection *conn = call->conn;
-	bool put = false, putu = false;
+	bool putu = false;
 
 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
 
@@ -573,23 +573,13 @@ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 
 	rxrpc_put_call_slot(call);
 
-	/* Make sure we don't get any more notifications */
+	/* Note that at this point, the call may still be on or may have been
+	 * added back on to the socket receive queue.  recvmsg() must discard
+	 * released calls.  The CALL_RELEASED flag should prevent further
+	 * notifications.
+	 */
 	spin_lock_irq(&rx->recvmsg_lock);
-
-	if (!list_empty(&call->recvmsg_link)) {
-		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
-		       call, call->events, call->flags);
-		list_del(&call->recvmsg_link);
-		put = true;
-	}
-
-	/* list_empty() must return false in rxrpc_notify_socket() */
-	call->recvmsg_link.next = NULL;
-	call->recvmsg_link.prev = NULL;
-
 	spin_unlock_irq(&rx->recvmsg_lock);
-	if (put)
-		rxrpc_put_call(call, rxrpc_call_put_unnotify);
 
 	write_lock(&rx->call_lock);
 
@@ -638,6 +628,12 @@ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 		rxrpc_put_call(call, rxrpc_call_put_release_sock);
 	}
 
+	while ((call = list_first_entry_or_null(&rx->recvmsg_q,
+						struct rxrpc_call, recvmsg_link))) {
+		list_del_init(&call->recvmsg_link);
+		rxrpc_put_call(call, rxrpc_call_put_release_recvmsg_q);
+	}
+
 	_leave("");
 }
 
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 6990e37697de..7fa7e77f6bb9 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -29,6 +29,10 @@ void rxrpc_notify_socket(struct rxrpc_call *call)
 
 	if (!list_empty(&call->recvmsg_link))
 		return;
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		rxrpc_see_call(call, rxrpc_call_see_notify_released);
+		return;
+	}
 
 	rcu_read_lock();
 

[PATCH net 4/5] rxrpc: Fix transmission of an abort in response to an abort

[David Howells]

Under some circumstances, such as when a server socket is closing, ABORT
packets will be generated in response to incoming packets.  Unfortunately,
this also may include generating aborts in response to incoming aborts -
which may cause a cycle.  It appears this may be made possible by giving
the client a multicast address.

Fix this such that rxrpc_reject_packet() will refuse to generate aborts in
response to aborts.

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Linus Torvalds <torvalds@linux-foundation.org>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
cc: stable@vger.kernel.org
---
 net/rxrpc/output.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index ef7b3096c95e..17c33b5cf7dd 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -814,6 +814,9 @@ void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 	__be32 code;
 	int ret, ioc;
 
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
+		return; /* Never abort an abort. */
+
 	rxrpc_see_skb(skb, rxrpc_skb_see_reject);
 
 	iov[0].iov_base = &whdr;

[PATCH net 5/5] rxrpc: Fix to use conn aborts for conn-wide failures

[David Howells]

Fix rxrpc to use connection-level aborts for things that affect the whole
connection, such as the service ID not matching a local service.

Fixes: 57af281e5389 ("rxrpc: Tidy up abort generation infrastructure")
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
cc: stable@vger.kernel.org
---
 include/trace/events/rxrpc.h |  1 +
 net/rxrpc/ar-internal.h      |  3 +++
 net/rxrpc/call_accept.c      | 12 ++++++------
 net/rxrpc/io_thread.c        | 14 ++++++++++++++
 net/rxrpc/output.c           | 19 ++++++++++---------
 net/rxrpc/security.c         |  8 ++++----
 6 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 8e5a73eb5268..de6f6d25767c 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -322,6 +322,7 @@
 	EM(rxrpc_call_put_kernel,		"PUT kernel  ") \
 	EM(rxrpc_call_put_poke,			"PUT poke    ") \
 	EM(rxrpc_call_put_recvmsg,		"PUT recvmsg ") \
+	EM(rxrpc_call_put_release_recvmsg_q,	"PUT rls-rcmq") \
 	EM(rxrpc_call_put_release_sock,		"PUT rls-sock") \
 	EM(rxrpc_call_put_release_sock_tba,	"PUT rls-sk-a") \
 	EM(rxrpc_call_put_sendmsg,		"PUT sendmsg ") \
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index df1a618dbf7d..5b7342d43486 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -44,6 +44,7 @@ enum rxrpc_skb_mark {
 	RXRPC_SKB_MARK_SERVICE_CONN_SECURED, /* Service connection response has been verified */
 	RXRPC_SKB_MARK_REJECT_BUSY,	/* Reject with BUSY */
 	RXRPC_SKB_MARK_REJECT_ABORT,	/* Reject with ABORT (code in skb->priority) */
+	RXRPC_SKB_MARK_REJECT_CONN_ABORT, /* Reject with connection ABORT (code in skb->priority) */
 };
 
 /*
@@ -1253,6 +1254,8 @@ int rxrpc_encap_rcv(struct sock *, struct sk_buff *);
 void rxrpc_error_report(struct sock *);
 bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
 			s32 abort_code, int err);
+bool rxrpc_direct_conn_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
+			     s32 abort_code, int err);
 int rxrpc_io_thread(void *data);
 void rxrpc_post_response(struct rxrpc_connection *conn, struct sk_buff *skb);
 static inline void rxrpc_wake_up_io_thread(struct rxrpc_local *local)
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index a4d76f2da684..00982a030744 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -374,8 +374,8 @@ bool rxrpc_new_incoming_call(struct rxrpc_local *local,
 	spin_lock(&rx->incoming_lock);
 	if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
 	    rx->sk.sk_state == RXRPC_CLOSE) {
-		rxrpc_direct_abort(skb, rxrpc_abort_shut_down,
-				   RX_INVALID_OPERATION, -ESHUTDOWN);
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_shut_down,
+					RX_INVALID_OPERATION, -ESHUTDOWN);
 		goto no_call;
 	}
 
@@ -422,12 +422,12 @@ bool rxrpc_new_incoming_call(struct rxrpc_local *local,
 
 unsupported_service:
 	read_unlock_irq(&local->services_lock);
-	return rxrpc_direct_abort(skb, rxrpc_abort_service_not_offered,
-				  RX_INVALID_OPERATION, -EOPNOTSUPP);
+	return rxrpc_direct_conn_abort(skb, rxrpc_abort_service_not_offered,
+				       RX_INVALID_OPERATION, -EOPNOTSUPP);
 unsupported_security:
 	read_unlock_irq(&local->services_lock);
-	return rxrpc_direct_abort(skb, rxrpc_abort_service_not_offered,
-				  RX_INVALID_OPERATION, -EKEYREJECTED);
+	return rxrpc_direct_conn_abort(skb, rxrpc_abort_service_not_offered,
+				       RX_INVALID_OPERATION, -EKEYREJECTED);
 no_call:
 	spin_unlock(&rx->incoming_lock);
 	read_unlock_irq(&local->services_lock);
diff --git a/net/rxrpc/io_thread.c b/net/rxrpc/io_thread.c
index 27b650d30f4d..e939ecf417c4 100644
--- a/net/rxrpc/io_thread.c
+++ b/net/rxrpc/io_thread.c
@@ -97,6 +97,20 @@ bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
 	return false;
 }
 
+/*
+ * Directly produce a connection abort from a packet.
+ */
+bool rxrpc_direct_conn_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
+			     s32 abort_code, int err)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_abort(0, why, sp->hdr.cid, 0, sp->hdr.seq, abort_code, err);
+	skb->mark = RXRPC_SKB_MARK_REJECT_CONN_ABORT;
+	skb->priority = abort_code;
+	return false;
+}
+
 static bool rxrpc_bad_message(struct sk_buff *skb, enum rxrpc_abort_reason why)
 {
 	return rxrpc_direct_abort(skb, why, RX_PROTOCOL_ERROR, -EBADMSG);
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 17c33b5cf7dd..8b5903b6e481 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -829,7 +829,13 @@ void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 	msg.msg_controllen = 0;
 	msg.msg_flags = 0;
 
-	memset(&whdr, 0, sizeof(whdr));
+	whdr = (struct rxrpc_wire_header) {
+		.epoch		= htonl(sp->hdr.epoch),
+		.cid		= htonl(sp->hdr.cid),
+		.callNumber	= htonl(sp->hdr.callNumber),
+		.serviceId	= htons(sp->hdr.serviceId),
+		.flags		= ~sp->hdr.flags & RXRPC_CLIENT_INITIATED,
+	};
 
 	switch (skb->mark) {
 	case RXRPC_SKB_MARK_REJECT_BUSY:
@@ -837,6 +843,9 @@ void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 		size = sizeof(whdr);
 		ioc = 1;
 		break;
+	case RXRPC_SKB_MARK_REJECT_CONN_ABORT:
+		whdr.callNumber	= 0;
+		fallthrough;
 	case RXRPC_SKB_MARK_REJECT_ABORT:
 		whdr.type = RXRPC_PACKET_TYPE_ABORT;
 		code = htonl(skb->priority);
@@ -850,14 +859,6 @@ void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
 	if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
 		msg.msg_namelen = srx.transport_len;
 
-		whdr.epoch	= htonl(sp->hdr.epoch);
-		whdr.cid	= htonl(sp->hdr.cid);
-		whdr.callNumber	= htonl(sp->hdr.callNumber);
-		whdr.serviceId	= htons(sp->hdr.serviceId);
-		whdr.flags	= sp->hdr.flags;
-		whdr.flags	^= RXRPC_CLIENT_INITIATED;
-		whdr.flags	&= RXRPC_CLIENT_INITIATED;
-
 		iov_iter_kvec(&msg.msg_iter, WRITE, iov, ioc, size);
 		ret = do_udp_sendmsg(local->socket, &msg, size);
 		if (ret < 0)
diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
index 078d91a6b77f..2bfbf2b2bb37 100644
--- a/net/rxrpc/security.c
+++ b/net/rxrpc/security.c
@@ -140,15 +140,15 @@ const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
 
 	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
 	if (!sec) {
-		rxrpc_direct_abort(skb, rxrpc_abort_unsupported_security,
-				   RX_INVALID_OPERATION, -EKEYREJECTED);
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_unsupported_security,
+					RX_INVALID_OPERATION, -EKEYREJECTED);
 		return NULL;
 	}
 
 	if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
 	    !rx->securities) {
-		rxrpc_direct_abort(skb, rxrpc_abort_no_service_key,
-				   sec->no_key_abort, -EKEYREJECTED);
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_no_service_key,
+					sec->no_key_abort, -EKEYREJECTED);
 		return NULL;
 	}
 

Re: [PATCH net 3/5] rxrpc: Fix notification vs call-release vs recvmsg

[Simon Horman]

On Wed, Jul 16, 2025 at 12:53:02PM +0100, David Howells wrote:
> When a call is released, rxrpc takes the spinlock and removes it from
> ->recvmsg_q in an effort to prevent racing recvmsg() invocations from
> seeing the same call.  Now, rxrpc_recvmsg() only takes the spinlock when
> actually removing a call from the queue; it doesn't, however, take it in
> the lead up to that when it checks to see if the queue is empty.  It *does*
> hold the socket lock, which prevents a recvmsg/recvmsg race - but this
> doesn't prevent sendmsg from ending the call because sendmsg() drops the
> socket lock and relies on the call->user_mutex.
> 
> Fix this by firstly removing the bit in rxrpc_release_call() that dequeues
> the released call and, instead, rely on recvmsg() to simply discard
> released calls (done in a preceding fix).
> 
> Secondly, rxrpc_notify_socket() is abandoned if the call is already marked
> as released rather than trying to be clever by setting both pointers in
> call->recvmsg_link to NULL to trick list_empty().  This isn't perfect and
> can still race, resulting in a released call on the queue, but recvmsg()
> will now clean that up.
> 
> Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
> Signed-off-by: David Howells <dhowells@redhat.com>
> Reviewed-by: Jeffrey Altman <jaltman@auristor.com>

...

> diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c

...

> @@ -638,6 +628,12 @@ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
>  		rxrpc_put_call(call, rxrpc_call_put_release_sock);
>  	}
>  
> +	while ((call = list_first_entry_or_null(&rx->recvmsg_q,
> +						struct rxrpc_call, recvmsg_link))) {
> +		list_del_init(&call->recvmsg_link);
> +		rxrpc_put_call(call, rxrpc_call_put_release_recvmsg_q);
> +	}
> +
>  	_leave("");
>  }
>  

Hi David,

I believe it is addressed in patch 5/5.
But unfortunately this change breaks bisection.

  .../call_object.c:634:24: error: use of undeclared identifier 'rxrpc_call_put_release_recvmsg_q'
    634 |                 rxrpc_put_call(call, rxrpc_call_put_release_recvmsg_q);
        |                                      ^

-- 
pw-bot: changes-requested