xfrm: Return error on unknown encap_type in init_state

Currently esp will happily create an xfrm state with an unknown encap type for IPv4, without setting the necessary state parameters. This patch fixes it by returning -EINVAL. There is a similar problem in IPv6 where if the mode is unknown we will skip initialisation while returning zero. However, this is harmless as the mode has already been checked further up the stack. This patch removes this anomaly by aligning the IPv6 behaviour with IPv4 and treating unknown modes (which cannot actually happen) as transport mode. Fixes: 38320c7 ("[IPSEC]: Use crypto_aead and authenc in ESP") Signed-off-by: Herbert Xu <[email protected]> Signed-off-by: Steffen Klassert <[email protected]>
thoughtpolice · Jan 8, 2018 · bcfd09f · bcfd09f
1 parent d16b46e
commit bcfd09f
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
@@ -981,6 +981,7 @@ static int esp_init_state(struct xfrm_state *x)
 
 		switch (encap->encap_type) {
 		default:
+			err = -EINVAL;
 			goto error;
 		case UDP_ENCAP_ESPINUDP:
 			x->props.header_len += sizeof(struct udphdr);

diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
@@ -890,13 +890,12 @@ static int esp6_init_state(struct xfrm_state *x)
 			x->props.header_len += IPV4_BEET_PHMAXLEN +
 					       (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
 		break;
+	default:
 	case XFRM_MODE_TRANSPORT:
 		break;
 	case XFRM_MODE_TUNNEL:
 		x->props.header_len += sizeof(struct ipv6hdr);
 		break;
-	default:
-		goto error;
 	}
 
 	align = ALIGN(crypto_aead_blocksize(aead), 4);