kernel.git/net/sctp/ipv6.c, branch linux-5.11.y

net-ipv6: bugfix - raw & sctp - switch to ipv6_can_nonlocal_bind()

2021-04-14T06:47:13Z

commit 630e4576f83accf90366686f39808d665d8dbecc upstream. Found by virtue of ipv6 raw sockets not honouring the per-socket IP{,V6}_FREEBIND setting. Based on hits found via: git grep '[.]ip_nonlocal_bind' We fix both raw ipv6 sockets to honour IP{,V6}_FREEBIND and IP{,V6}_TRANSPARENT, and we fix sctp sockets to honour IP{,V6}_TRANSPARENT (they already honoured FREEBIND), and not just the ipv6 'ip_nonlocal_bind' sysctl. The helper is defined as: static inline bool ipv6_can_nonlocal_bind(struct net *net, struct inet_sock *inet) { return net->ipv6.sysctl.ip_nonlocal_bind || inet->freebind || inet->transparent; } so this change only widens the accepted opt-outs and is thus a clean bugfix. I'm not entirely sure what 'fixes' tag to add, since this is AFAICT an ancient bug, but IMHO this should be applied to stable kernels as far back as possible. As such I'm adding a 'fixes' tag with the commit that originally added the helper, which happened in 4.19. Backporting to older LTS kernels (at least 4.9 and 4.14) would presumably require open-coding it or backporting the helper as well. Other possibly relevant commits: v4.18-rc6-1502-g83ba4645152d net: add helpers checking if socket can be bound to nonlocal address v4.18-rc6-1431-gd0c1f01138c4 net/ipv6: allow any source address for sendmsg pktinfo with ip_nonlocal_bind v4.14-rc5-271-gb71d21c274ef sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND v4.7-rc7-1883-g9b9742022888 sctp: support ipv6 nonlocal bind v4.1-12247-g35a256fee52c ipv6: Nonlocal bind Cc: Lorenzo Colitti Fixes: 83ba4645152d ("net: add helpers checking if socket can be bound to nonlocal address") Signed-off-by: Maciej Żenczykowski Reviewed-By: Lorenzo Colitti Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: bring inet(6)_skb_parm back to sctp_input_cb

2020-11-05T22:27:30Z

inet(6)_skb_parm was removed from sctp_input_cb by Commit a1dd2cf2f1ae ("sctp: allow changing transport encap_port by peer packets"), as it thought sctp_input_cb->header is not used any more in SCTP. syzbot reported a crash: [ ] BUG: KASAN: use-after-free in decode_session6+0xe7c/0x1580 [ ] [ ] Call Trace: [ ] [ ] dump_stack+0x107/0x163 [ ] kasan_report.cold+0x1f/0x37 [ ] decode_session6+0xe7c/0x1580 [ ] __xfrm_policy_check+0x2fa/0x2850 [ ] sctp_rcv+0x12b0/0x2e30 [ ] sctp6_rcv+0x22/0x40 [ ] ip6_protocol_deliver_rcu+0x2e8/0x1680 [ ] ip6_input_finish+0x7f/0x160 [ ] ip6_input+0x9c/0xd0 [ ] ipv6_rcv+0x28e/0x3c0 It was caused by sctp_input_cb->header/IP6CB(skb) still used in sctp rx path decode_session6() but some members overwritten by sctp6_rcv(). This patch is to fix it by bring inet(6)_skb_parm back to sctp_input_cb and not overwriting it in sctp4/6_rcv() and sctp_udp_rcv(). Reported-by: syzbot+5be8aebb1b7dfa90ef31@syzkaller.appspotmail.com Fixes: a1dd2cf2f1ae ("sctp: allow changing transport encap_port by peer packets") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Link: https://lore.kernel.org/r/136c1a7a419341487c504be6d1996928d9d16e02.1604472932.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

sctp: support for sending packet over udp6 sock

2020-10-30T22:24:35Z

This one basically does the similar things in sctp_v6_xmit as does for udp4 sock in the last patch, just note that: 1. label needs to be calculated, as it's the param of udp_tunnel6_xmit_skb(). 2. The 'nocheck' param of udp_tunnel6_xmit_skb() is false, as required by RFC. v1->v2: - Use sp->udp_port instead in sctp_v6_xmit(), which is more safe. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski

sctp: allow changing transport encap_port by peer packets

2020-10-30T22:24:16Z

As rfc6951#section-5.4 says: "After finding the SCTP association (which includes checking the verification tag), the UDP source port MUST be stored as the encapsulation port for the destination address the SCTP packet is received from (see Section 5.1). When a non-encapsulated SCTP packet is received by the SCTP stack, the encapsulation of outgoing packets belonging to the same association and the corresponding destination address MUST be disabled." transport encap_port should be updated by a validated incoming packet's udp src port. We save the udp src port in sctp_input_cb->encap_port, and then update the transport in two places: 1. right after vtag is verified, which is required by RFC, and this allows the existent transports to be updated by the chunks that can only be processed on an asoc. 2. right before processing the 'init' where the transports are added, and this allows building a sctp over udp connection by client with the server not knowing the remote encap port. 3. when processing ootb_pkt and creating the temporary transport for the reply pkt. Note that sctp_input_cb->header is removed, as it's not used any more in sctp. v1->v2: - Change encap_port as __be16 for sctp_input_cb. Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

net/ipv6: remove compat_ipv6_{get,set}sockopt

2020-07-20T01:16:41Z

Handle the few cases that need special treatment in-line using in_compat_syscall(). This also removes all the now unused compat_{get,set}sockopt methods. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller

net: remove compat_sock_common_{get,set}sockopt

2020-07-20T01:16:40Z

Add the compat handling to sock_common_{get,set}sockopt instead, keyed of in_compat_syscall(). This allow to remove the now unused ->compat_{get,set}sockopt methods from struct proto_ops. Signed-off-by: Christoph Hellwig Acked-by: Matthieu Baerts Acked-by: Stefan Schmidt Signed-off-by: David S. Miller

ipv6: move SIOCADDRT and SIOCDELRT handling into ->compat_ioctl

2020-05-19T00:35:02Z

To prepare removing the global routing_ioctl hack start lifting the code into a newly added ipv6 ->compat_ioctl handler. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller

sctp: fix possibly using a bad saddr with a given dst

2020-03-30T05:01:43Z

Under certain circumstances, depending on the order of addresses on the interfaces, it could be that sctp_v[46]_get_dst() would return a dst with a mismatched struct flowi. For example, if when walking through the bind addresses and the first one is not a match, it saves the dst as a fallback (added in 410f03831c07), but not the flowi. Then if the next one is also not a match, the previous dst will be returned but with the flowi information for the 2nd address, which is wrong. The fix is to use a locally stored flowi that can be used for such attempts, and copy it to the parameter only in case it is a possible match, together with the corresponding dst entry. The patch updates IPv6 code mostly just to be in sync. Even though the issue is also present there, it fallback is not expected to work with IPv6. Fixes: 410f03831c07 ("sctp: add routing output fallback") Reported-by: Jin Meng Signed-off-by: Marcelo Ricardo Leitner Tested-by: Xin Long Signed-off-by: David S. Miller

net: ipv6: add net argument to ip6_dst_lookup_flow

2019-12-04T20:27:12Z

This will be used in the conversion of ipv6_stub to ip6_dst_lookup_flow, as some modules currently pass a net argument without a socket to ip6_dst_lookup. This is equivalent to commit 343d60aada5a ("ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument"). Signed-off-by: Sabrina Dubroca Signed-off-by: David S. Miller