4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Piotr Sawicki p.sawicki2@partner.samsung.com
[ Upstream commit 129a99890936766f4b69b9da7ed88366313a9210 ]
A socket which has sk_family set to PF_INET6 is able to receive not only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
Prior to this patch, the smk_skb_to_addr_ipv6() could have been called for socket buffers containing IPv4 packets, in result such traffic was allowed.
Signed-off-by: Piotr Sawicki p.sawicki2@partner.samsung.com Signed-off-by: Casey Schaufler casey@schaufler-ca.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- security/smack/smack_lsm.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
--- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3924,15 +3924,19 @@ static int smack_socket_sock_rcv_skb(str struct smack_known *skp = NULL; int rc = 0; struct smk_audit_info ad; + u16 family = sk->sk_family; #ifdef CONFIG_AUDIT struct lsm_network_audit net; #endif #if IS_ENABLED(CONFIG_IPV6) struct sockaddr_in6 sadd; int proto; + + if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) + family = PF_INET; #endif /* CONFIG_IPV6 */
- switch (sk->sk_family) { + switch (family) { case PF_INET: #ifdef CONFIG_SECURITY_SMACK_NETFILTER /* @@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(str */ netlbl_secattr_init(&secattr);
- rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) skp = smack_from_secattr(&secattr, ssp); else @@ -3963,7 +3967,7 @@ access_check: #endif #ifdef CONFIG_AUDIT smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); - ad.a.u.net->family = sk->sk_family; + ad.a.u.net->family = family; ad.a.u.net->netif = skb->skb_iif; ipv4_skb_to_auditdata(skb, &ad.a, NULL); #endif @@ -3977,7 +3981,7 @@ access_check: rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in, MAY_WRITE, rc); if (rc != 0) - netlbl_skbuff_err(skb, sk->sk_family, rc, 0); + netlbl_skbuff_err(skb, family, rc, 0); break; #if IS_ENABLED(CONFIG_IPV6) case PF_INET6: @@ -3993,7 +3997,7 @@ access_check: skp = smack_net_ambient; #ifdef CONFIG_AUDIT smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); - ad.a.u.net->family = sk->sk_family; + ad.a.u.net->family = family; ad.a.u.net->netif = skb->skb_iif; ipv6_skb_to_auditdata(skb, &ad.a, NULL); #endif /* CONFIG_AUDIT */