af_key: Do not call xfrm_probe_algs in parallel

[ 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>

diff --git a/net/key/af_key.c b/net/key/af_key.c
index d93bde6..53cca90 100644 (file)
--- 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);