From: David Howells <dhowells@redhat.com>
Date: Thu, 17 Jul 2025 07:43:44 +0000 (+0100)
Subject: rxrpc: Fix transmission of an abort in response to an abort
X-Git-Tag: v6.16-rc7~37^2~1^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e9c0b96ec0a34fcacdf9365713578d83cecac34c;p=thirdparty%2Flinux.git

rxrpc: Fix transmission of an abort in response to an abort

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: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250717074350.3767366-5-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index ef7b3096c95eb..17c33b5cf7dde 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;