kernel/git/stable/linux.git/net/ipv6, branch linux-4.17.y

ipv6: make ipv6_renew_options() interrupt/kernel safe

2018-08-24T11:07:00+00:00

[ Upstream commit a9ba23d48dbc6ffd08426bb10f05720e0b9f5c14 ] At present the ipv6_renew_options_kern() function ends up calling into access_ok() which is problematic if done from inside an interrupt as access_ok() calls WARN_ON_IN_IRQ() on some (all?) architectures (x86-64 is affected). Example warning/backtrace is shown below: WARNING: CPU: 1 PID: 3144 at lib/usercopy.c:11 _copy_from_user+0x85/0x90 ... Call Trace: ipv6_renew_option+0xb2/0xf0 ipv6_renew_options+0x26a/0x340 ipv6_renew_options_kern+0x2c/0x40 calipso_req_setattr+0x72/0xe0 netlbl_req_setattr+0x126/0x1b0 selinux_netlbl_inet_conn_request+0x80/0x100 selinux_inet_conn_request+0x6d/0xb0 security_inet_conn_request+0x32/0x50 tcp_conn_request+0x35f/0xe00 ? __lock_acquire+0x250/0x16c0 ? selinux_socket_sock_rcv_skb+0x1ae/0x210 ? tcp_rcv_state_process+0x289/0x106b tcp_rcv_state_process+0x289/0x106b ? tcp_v6_do_rcv+0x1a7/0x3c0 tcp_v6_do_rcv+0x1a7/0x3c0 tcp_v6_rcv+0xc82/0xcf0 ip6_input_finish+0x10d/0x690 ip6_input+0x45/0x1e0 ? ip6_rcv_finish+0x1d0/0x1d0 ipv6_rcv+0x32b/0x880 ? ip6_make_skb+0x1e0/0x1e0 __netif_receive_skb_core+0x6f2/0xdf0 ? process_backlog+0x85/0x250 ? process_backlog+0x85/0x250 ? process_backlog+0xec/0x250 process_backlog+0xec/0x250 net_rx_action+0x153/0x480 __do_softirq+0xd9/0x4f7 do_softirq_own_stack+0x2a/0x40 ... While not present in the backtrace, ipv6_renew_option() ends up calling access_ok() via the following chain: access_ok() _copy_from_user() copy_from_user() ipv6_renew_option() The fix presented in this patch is to perform the userspace copy earlier in the call chain such that it is only called when the option data is actually coming from userspace; that place is do_ipv6_setsockopt(). Not only does this solve the problem seen in the backtrace above, it also allows us to simplify the code quite a bit by removing ipv6_renew_options_kern() completely. We also take this opportunity to cleanup ipv6_renew_options()/ipv6_renew_option() a small amount as well. This patch is heavily based on a rough patch by Al Viro. I've taken his original patch, converted a kmemdup() call in do_ipv6_setsockopt() to a memdup_user() call, made better use of the e_inval jump target in the same function, and cleaned up the use ipv6_renew_option() by ipv6_renew_options(). CC: Al Viro Signed-off-by: Paul Moore Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: set module owner for icmp(6) matches

2018-08-24T11:06:59+00:00

[ Upstream commit d376bef9c29b3c65aeee4e785fffcd97ef0a9a81 ] nft_compat relies on xt_request_find_match to increment refcount of the module that provides the match/target. The (builtin) icmp matches did't set the module owner so it was possible to rmmod ip(6)tables while icmp extensions were still in use. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ipv6: mcast: fix unsolicited report interval after receiving querys

2018-08-24T11:06:47+00:00

[ Upstream commit 6c6da92808442908287fae8ebb0ca041a52469f4 ] After recieving MLD querys, we update idev->mc_maxdelay with max_delay from query header. This make the later unsolicited reports have the same interval with mc_maxdelay, which means we may send unsolicited reports with long interval time instead of default configured interval time. Also as we will not call ipv6_mc_reset() after device up. This issue will be there even after leave the group and join other groups. Fixes: fc4eba58b4c14 ("ipv6: make unsolicited report intervals configurable for mld") Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

netfilter: ipv6: nf_defrag: reduce struct net memory waste

2018-08-24T11:06:39+00:00

[ Upstream commit 9ce7bc036ae4cfe3393232c86e9e1fea2153c237 ] It is a waste of memory to use a full "struct netns_sysctl_ipv6" while only one pointer is really used, considering netns_sysctl_ipv6 keeps growing. Also, since "struct netns_frags" has cache line alignment, it is better to move the frags_hdr pointer outside, otherwise we spend a full cache line for this pointer. This saves 192 bytes of memory per netns. Fixes: c038a767cd69 ("ipv6: add a new namespace for nf_conntrack_reasm") Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ip6_tunnel: use the right value for ipv4 min mtu check in ip6_tnl_xmit

2018-08-22T05:44:52+00:00

[ Upstream commit 82a40777de12728dedf4075453b694f0d1baee80 ] According to RFC791, 68 bytes is the minimum size of IPv4 datagram every device must be able to forward without further fragmentation while 576 bytes is the minimum size of IPv4 datagram every device has to be able to receive, so in ip6_tnl_xmit(), 68(IPV4_MIN_MTU) should be the right value for the ipv4 min mtu check in ip6_tnl_xmit. While at it, change to use max() instead of if statement. Fixes: c9fefa08190f ("ip6_tunnel: get the min mtu properly in ip6_tnl_xmit") Reported-by: Sabrina Dubroca Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/ipv6: Fix linklocal to global address with VRF

2018-07-28T05:57:15+00:00

[ Upstream commit 24b711edfc34bc45777a3f068812b7d1ed004a5d ] Example setup: host: ip -6 addr add dev eth1 2001:db8:104::4 where eth1 is enslaved to a VRF switch: ip -6 ro add 2001:db8:104::4/128 dev br1 where br1 only has an LLA ping6 2001:db8:104::4 ssh 2001:db8:104::4 (NOTE: UDP works fine if the PKTINFO has the address set to the global address and ifindex is set to the index of eth1 with a destination an LLA). For ICMP, icmp6_iif needs to be updated to check if skb->dev is an L3 master. If it is then return the ifindex from rt6i_idev similar to what is done for loopback. For TCP, restore the original tcp_v6_iif definition which is needed in most places and add a new tcp_v6_iif_l3_slave that considers the l3_slave variability. This latter check is only needed for socket lookups. Fixes: 9ff74384600a ("net: vrf: Handle ipv6 multicast and link-local addresses") Signed-off-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

multicast: do not restore deleted record source filter mode to new one

2018-07-28T05:57:15+00:00

There are two scenarios that we will restore deleted records. The first is when device down and up(or unmap/remap). In this scenario the new filter mode is same with previous one. Because we get it from in_dev->mc_list and we do not touch it during device down and up. The other scenario is when a new socket join a group which was just delete and not finish sending status reports. In this scenario, we should use the current filter mode instead of restore old one. Here are 4 cases in total. old_socket new_socket before_fix after_fix IN(A) IN(A) ALLOW(A) ALLOW(A) IN(A) EX( ) TO_IN( ) TO_EX( ) EX( ) IN(A) TO_EX( ) ALLOW(A) EX( ) EX( ) TO_EX( ) TO_EX( ) Fixes: 24803f38a5c0b (igmp: do not remove igmp souce list info when set link down) Fixes: 1666d49e1d416 (mld: do not remove mld souce list info when set link down) Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull

2018-07-28T05:57:13+00:00

[ Upstream commit 2efd4fca703a6707cad16ab486eaab8fc7f0fd49 ] Syzbot reported a read beyond the end of the skb head when returning IPV6_ORIGDSTADDR: BUG: KMSAN: kernel-infoleak in put_cmsg+0x5ef/0x860 net/core/scm.c:242 CPU: 0 PID: 4501 Comm: syz-executor128 Not tainted 4.17.0+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1125 kmsan_internal_check_memory+0x138/0x1f0 mm/kmsan/kmsan.c:1219 kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1261 copy_to_user include/linux/uaccess.h:184 [inline] put_cmsg+0x5ef/0x860 net/core/scm.c:242 ip6_datagram_recv_specific_ctl+0x1cf3/0x1eb0 net/ipv6/datagram.c:719 ip6_datagram_recv_ctl+0x41c/0x450 net/ipv6/datagram.c:733 rawv6_recvmsg+0x10fb/0x1460 net/ipv6/raw.c:521 [..] This logic and its ipv4 counterpart read the destination port from the packet at skb_transport_offset(skb) + 4. With MSG_MORE and a local SOCK_RAW sender, syzbot was able to cook a packet that stores headers exactly up to skb_transport_offset(skb) in the head and the remainder in a frag. Call pskb_may_pull before accessing the pointer to ensure that it lies in skb head. Link: http://lkml.kernel.org/r/CAF=yD-LEJwZj5a1-bAAj2Oy_hKmGygV6rsJ_WOrAYnv-fnayiQ@mail.gmail.com Reported-by: syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ip: hash fragments consistently

2018-07-28T05:57:13+00:00

[ Upstream commit 3dd1c9a1270736029ffca670e9bd0265f4120600 ] The skb hash for locally generated ip[v6] fragments belonging to the same datagram can vary in several circumstances: * for connected UDP[v6] sockets, the first fragment get its hash via set_owner_w()/skb_set_hash_from_sk() * for unconnected IPv6 UDPv6 sockets, the first fragment can get its hash via ip6_make_flowlabel()/skb_get_hash_flowi6(), if auto_flowlabel is enabled For the following frags the hash is usually computed via skb_get_hash(). The above can cause OoO for unconnected IPv6 UDPv6 socket: in that scenario the egress tx queue can be selected on a per packet basis via the skb hash. It may also fool flow-oriented schedulers to place fragments belonging to the same datagram in different flows. Fix the issue by copying the skb hash from the head frag into the others at fragmentation time. Before this commit: perf probe -a "dev_queue_xmit skb skb->hash skb->l4_hash:b1@0/8 skb->sw_hash:b1@1/8" netperf -H $IPV4 -t UDP_STREAM -l 5 -- -m 2000 -n & perf record -e probe:dev_queue_xmit -e probe:skb_set_owner_w -a sleep 0.1 perf script probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=3713014309 l4_hash=1 sw_hash=0 probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=0 l4_hash=0 sw_hash=0 After this commit: probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=2171763177 l4_hash=1 sw_hash=0 probe:dev_queue_xmit: (ffffffff8c6b1b20) hash=2171763177 l4_hash=1 sw_hash=0 Fixes: b73c3d0e4f0e ("net: Save TX flow hash in sock and set in skbuf on xmit") Fixes: 67800f9b1f4e ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel") Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6: make DAD fail with enhanced DAD when nonce length differs

2018-07-25T09:26:12+00:00

[ Upstream commit e66515999b627368892ccc9b3a13a506f2ea1357 ] Commit adc176c54722 ("ipv6 addrconf: Implemented enhanced DAD (RFC7527)") added enhanced DAD with a nonce length of 6 bytes. However, RFC7527 doesn't specify the length of the nonce, other than being 6 + 8*k bytes, with integer k >= 0 (RFC3971 5.3.2). The current implementation simply assumes that the nonce will always be 6 bytes, but others systems are free to choose different sizes. If another system sends a nonce of different length but with the same 6 bytes prefix, it shouldn't be considered as the same nonce. Thus, check that the length of the received nonce is the same as the length we sent. Ugly scapy test script running on veth0: def loop(): pkt=sniff(iface="veth0", filter="icmp6", count=1) pkt = pkt[0] b = bytearray(pkt[Raw].load) b[1] += 1 b += b'\xde\xad\xbe\xef\xde\xad\xbe\xef' pkt[Raw].load = bytes(b) pkt[IPv6].plen += 8 # fixup checksum after modifying the payload pkt[IPv6].payload.cksum -= 0x3b44 if pkt[IPv6].payload.cksum < 0: pkt[IPv6].payload.cksum += 0xffff sendp(pkt, iface="veth0") This should result in DAD failure for any address added to veth0's peer, but is currently ignored. Fixes: adc176c54722 ("ipv6 addrconf: Implemented enhanced DAD (RFC7527)") Signed-off-by: Sabrina Dubroca Reviewed-by: Stefano Brivio Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman