From: Herbert Xu <herbert@gondor.apana.org.au>
To: syzbot <syzbot+1e9af9185d8850e2c2fa@syzkaller.appspotmail.com>
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
pabeni@redhat.com, steffen.klassert@secunet.com,
syzkaller-bugs@googlegroups.com
Subject: [PATCH] af_key: Fix send_acquire race with pfkey_register
Date: Mon, 24 Oct 2022 13:10:34 +0800 [thread overview]
Message-ID: <Y1YeSj2vwPvRAW61@gondor.apana.org.au> (raw)
In-Reply-To: <000000000000fd9a4005ebbeac67@google.com>
With name space support, it is possible for a pfkey_register to
occur in the middle of a send_acquire, thus changing the number
of supported algorithms.
This can be fixed by taking a mutex to make it single-threaded
again.
Reported-by: syzbot+1e9af9185d8850e2c2fa@syzkaller.appspotmail.com
Fixes: 283bc9f35bbb ("xfrm: Namespacify xfrm state/policy locks")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/net/key/af_key.c b/net/key/af_key.c
index c85df5b958d2..4ceef96fef57 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3160,6 +3160,7 @@ static int pfkey_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *t, struct
(sockaddr_size * 2) +
sizeof(struct sadb_x_policy);
+ mutex_lock(&pfkey_mutex);
if (x->id.proto == IPPROTO_AH)
size += count_ah_combs(t);
else if (x->id.proto == IPPROTO_ESP)
@@ -3171,8 +3172,10 @@ static int pfkey_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *t, struct
}
skb = alloc_skb(size + 16, GFP_ATOMIC);
- if (skb == NULL)
+ if (skb == NULL) {
+ mutex_unlock(&pfkey_mutex);
return -ENOMEM;
+ }
hdr = skb_put(skb, sizeof(struct sadb_msg));
hdr->sadb_msg_version = PF_KEY_V2;
@@ -3228,6 +3231,7 @@ static int pfkey_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *t, struct
dump_ah_combs(skb, t);
else if (x->id.proto == IPPROTO_ESP)
dump_esp_combs(skb, t);
+ mutex_unlock(&pfkey_mutex);
/* security context */
if (xfrm_ctx) {
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
next prev parent reply other threads:[~2022-10-24 5:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-24 2:37 [syzbot] kernel BUG in warn_crc32c_csum_combine syzbot
2022-10-24 2:49 ` Eric Dumazet
2022-10-24 5:01 ` Herbert Xu
2022-10-24 5:10 ` Herbert Xu [this message]
2022-10-24 5:21 ` [PATCH] af_key: Fix send_acquire race with pfkey_register Eric Dumazet
2022-10-24 6:06 ` [v2 PATCH] " Herbert Xu
2022-10-24 6:31 ` Eric Dumazet
2022-10-25 5:46 ` Herbert Xu
2022-10-24 7:20 ` Sabrina Dubroca
2022-10-25 6:06 ` [v3 " Herbert Xu
2022-10-26 13:38 ` Sabrina Dubroca
2022-10-27 3:42 ` Herbert Xu
2022-10-27 3:45 ` Eric Dumazet
2022-10-27 3:55 ` Herbert Xu
2022-10-28 11:26 ` Steffen Klassert
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