[PATCH 5.19 015/158] af_key: Do not call xfrm_probe_algs in parallel

Greg Kroah-Hartman
2022-08-29T11:12:24Z

From: Herbert Xu <herbert@gondor.apana.org.au>

[ Upstream commit ba953a9d89a00c078b85f4b190bc1dde66fe16b5 ]

When namespace support was added to xfrm/afkey, it caused the
previously single-threaded call to xfrm_probe_algs to become
multi-threaded. This is buggy and needs to be fixed with a mutex.

Reported-by: Abhishek Shah <abhishek.shah@columbia.edu>
Fixes: 283bc9f35bbb ("xfrm: Namespacify xfrm state/policy locks")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/key/af_key.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index fb16d7c4e1b8d..20e73643b9c89 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1697,9 +1697,12 @@ static int pfkey_register(struct sock *sk, struct sk_buff *skb, const struct sad
pfk->registered |= (1<<hdr->sadb_msg_satype);
}

+ mutex_lock(&pfkey_mutex);
xfrm_probe_algs();

supp_skb = compose_sadb_supported(hdr, GFP_KERNEL | __GFP_ZERO);
+ mutex_unlock(&pfkey_mutex);
+
if (!supp_skb) {
if (hdr->sadb_msg_satype != SADB_SATYPE_UNSPEC)
pfk->registered &= ~(1<<hdr->sadb_msg_satype);
--
2.35.1