From 3f23fd03397e8a8a7f609923435c63f9fba0987b Mon Sep 17 00:00:00 2001
From: Xin Long <lucien.xin@gmail.com>
Date: Sat, 15 Jun 2024 14:27:20 -0400
Subject: [PATCH] tipc: force a dst refcount before doing decryption
[ Upstream commit 2ebe8f840c7450ecbfca9d18ac92e9ce9155e269 ]
As it says in commit 3bc07321ccc2 ("xfrm: Force a dst refcount before
entering the xfrm type handlers"):
"Crypto requests might return asynchronous. In this case we leave the
rcu protected region, so force a refcount on the skb's destination
entry before we enter the xfrm type input/output handlers."
On TIPC decryption path it has the same problem, and skb_dst_force()
should be called before doing decryption to avoid a possible crash.
Shuang reported this issue when this warning is triggered:
[] WARNING: include/net/dst.h:337 tipc_sk_rcv+0x1055/0x1ea0 [tipc]
[] Kdump: loaded Tainted: G W --------- - - 4.18.0-496.el8.x86_64+debug
[] Workqueue: crypto cryptd_queue_worker
[] RIP: 0010:tipc_sk_rcv+0x1055/0x1ea0 [tipc]
[] Call Trace:
[] tipc_sk_mcast_rcv+0x548/0xea0 [tipc]
[] tipc_rcv+0xcf5/0x1060 [tipc]
[] tipc_aead_decrypt_done+0x215/0x2e0 [tipc]
[] cryptd_aead_crypt+0xdb/0x190
[] cryptd_queue_worker+0xed/0x190
[] process_one_work+0x93d/0x17e0
Fixes: fc1b6d6de220 ("tipc: introduce TIPC encryption & authentication")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/fbe3195fad6997a4eec62d9bf076b2ad03ac336b.1718476040.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/tipc/node.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/tipc/node.c b/net/tipc/node.c
index a9c5b6594889b..cf9d9f9b97844 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -2107,6 +2107,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
} else {
n = tipc_node_find_by_id(net, ehdr->id);
}
+ skb_dst_force(skb);
tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b);
if (!skb)
return;
--
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