Messages in this thread Patch in this message | | | Date | Mon, 24 Oct 2022 13:10:34 +0800 | From | Herbert Xu <> | Subject | [PATCH] af_key: Fix send_acquire race with pfkey_register |
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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
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