linux/net/ipv6, branch v4.20

ipv6: tunnels: fix two use-after-free

2018-12-21T17:18:31Z

xfrm6_policy_check() might have re-allocated skb->head, we need to reload ipv6 header pointer. sysbot reported : BUG: KASAN: use-after-free in __ipv6_addr_type+0x302/0x32f net/ipv6/addrconf_core.c:40 Read of size 4 at addr ffff888191b8cb70 by task syz-executor2/1304 CPU: 0 PID: 1304 Comm: syz-executor2 Not tainted 4.20.0-rc7+ #356 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 __ipv6_addr_type+0x302/0x32f net/ipv6/addrconf_core.c:40 ipv6_addr_type include/net/ipv6.h:403 [inline] ip6_tnl_get_cap+0x27/0x190 net/ipv6/ip6_tunnel.c:727 ip6_tnl_rcv_ctl+0xdb/0x2a0 net/ipv6/ip6_tunnel.c:757 vti6_rcv+0x336/0x8f3 net/ipv6/ip6_vti.c:321 xfrm6_ipcomp_rcv+0x1a5/0x3a0 net/ipv6/xfrm6_protocol.c:132 ip6_protocol_deliver_rcu+0x372/0x1940 net/ipv6/ip6_input.c:394 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:443 IPVS: ftp: loaded support on port[0] = 21 ip6_mc_input+0x514/0x11c0 net/ipv6/ip6_input.c:537 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5083 process_backlog+0x24e/0x7a0 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x7fa/0x19b0 net/core/dev.c:6412 __do_softirq+0x308/0xb7e kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027 do_softirq.part.14+0x126/0x160 kernel/softirq.c:337 do_softirq+0x19/0x20 kernel/softirq.c:340 netif_rx_ni+0x521/0x860 net/core/dev.c:4569 dev_loopback_xmit+0x287/0x8c0 net/core/dev.c:3576 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_finish_output2+0x193a/0x2930 net/ipv6/ip6_output.c:84 ip6_fragment+0x2b06/0x3850 net/ipv6/ip6_output.c:727 ip6_finish_output+0x6b7/0xc50 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x232/0x9d0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] ip6_local_out+0xc5/0x1b0 net/ipv6/output_core.c:176 ip6_send_skb+0xbc/0x340 net/ipv6/ip6_output.c:1727 ip6_push_pending_frames+0xc5/0xf0 net/ipv6/ip6_output.c:1747 rawv6_push_pending_frames net/ipv6/raw.c:615 [inline] rawv6_sendmsg+0x3a3e/0x4b40 net/ipv6/raw.c:945 kobject: 'queues' (0000000089e6eea2): kobject_add_internal: parent: 'tunl0', set: '' kobject: 'queues' (0000000089e6eea2): kobject_uevent_env inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 kobject: 'queues' (0000000089e6eea2): kobject_uevent_env: filter function caused the event to drop! sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 sock_write_iter+0x35e/0x5c0 net/socket.c:900 call_write_iter include/linux/fs.h:1857 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 kobject: 'rx-0' (00000000e2d902d9): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'rx-0' (00000000e2d902d9): kobject_uevent_env vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 kobject: 'rx-0' (00000000e2d902d9): fill_kobj_path: path = '/devices/virtual/net/tunl0/queues/rx-0' __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 kobject: 'tx-0' (00000000443b70ac): kobject_add_internal: parent: 'queues', set: 'queues' entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9bd200bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457669 RDX: 000000000000058f RSI: 00000000200033c0 RDI: 0000000000000003 kobject: 'tx-0' (00000000443b70ac): kobject_uevent_env RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9bd200c6d4 R13: 00000000004c2dcc R14: 00000000004da398 R15: 00000000ffffffff Allocated by task 1304: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 __do_kmalloc_node mm/slab.c:3684 [inline] __kmalloc_node_track_caller+0x50/0x70 mm/slab.c:3698 __kmalloc_reserve.isra.41+0x41/0xe0 net/core/skbuff.c:140 __alloc_skb+0x155/0x760 net/core/skbuff.c:208 kobject: 'tx-0' (00000000443b70ac): fill_kobj_path: path = '/devices/virtual/net/tunl0/queues/tx-0' alloc_skb include/linux/skbuff.h:1011 [inline] __ip6_append_data.isra.49+0x2f1a/0x3f50 net/ipv6/ip6_output.c:1450 ip6_append_data+0x1bc/0x2d0 net/ipv6/ip6_output.c:1619 rawv6_sendmsg+0x15ab/0x4b40 net/ipv6/raw.c:938 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe kobject: 'gre0' (00000000cb1b2d7b): kobject_add_internal: parent: 'net', set: 'devices' Freed by task 1304: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 skb_free_head+0x93/0xb0 net/core/skbuff.c:553 pskb_expand_head+0x3b2/0x10d0 net/core/skbuff.c:1498 __pskb_pull_tail+0x156/0x18a0 net/core/skbuff.c:1896 pskb_may_pull include/linux/skbuff.h:2188 [inline] _decode_session6+0xd11/0x14d0 net/ipv6/xfrm6_policy.c:150 __xfrm_decode_session+0x71/0x140 net/xfrm/xfrm_policy.c:3272 kobject: 'gre0' (00000000cb1b2d7b): kobject_uevent_env __xfrm_policy_check+0x380/0x2c40 net/xfrm/xfrm_policy.c:3322 __xfrm_policy_check2 include/net/xfrm.h:1170 [inline] xfrm_policy_check include/net/xfrm.h:1175 [inline] xfrm6_policy_check include/net/xfrm.h:1185 [inline] vti6_rcv+0x4bd/0x8f3 net/ipv6/ip6_vti.c:316 xfrm6_ipcomp_rcv+0x1a5/0x3a0 net/ipv6/xfrm6_protocol.c:132 ip6_protocol_deliver_rcu+0x372/0x1940 net/ipv6/ip6_input.c:394 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:443 ip6_mc_input+0x514/0x11c0 net/ipv6/ip6_input.c:537 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5083 process_backlog+0x24e/0x7a0 net/core/dev.c:5923 kobject: 'gre0' (00000000cb1b2d7b): fill_kobj_path: path = '/devices/virtual/net/gre0' napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x7fa/0x19b0 net/core/dev.c:6412 __do_softirq+0x308/0xb7e kernel/softirq.c:292 The buggy address belongs to the object at ffff888191b8cac0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 176 bytes inside of 512-byte region [ffff888191b8cac0, ffff888191b8ccc0) The buggy address belongs to the page: page:ffffea000646e300 count:1 mapcount:0 mapping:ffff8881da800940 index:0x0 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0006eaaa48 ffffea00065356c8 ffff8881da800940 raw: 0000000000000000 ffff888191b8c0c0 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected kobject: 'queues' (000000005fd6226e): kobject_add_internal: parent: 'gre0', set: '' Memory state around the buggy address: ffff888191b8ca00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888191b8ca80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff888191b8cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888191b8cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888191b8cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 0d3c703a9d17 ("ipv6: Cleanup IPv6 tunnel receive path") Fixes: ed1efb2aefbb ("ipv6: Add support for IPsec virtual tunnel interfaces") Signed-off-by: Eric Dumazet Cc: Steffen Klassert Signed-off-by: David S. Miller

ipv6: frags: Fix bogus skb->sk in reassembled packets

2018-12-21T00:31:36Z

It was reported that IPsec would crash when it encounters an IPv6 reassembled packet because skb->sk is non-zero and not a valid pointer. This is because skb->sk is now a union with ip_defrag_offset. This patch fixes this by resetting skb->sk when exiting from the reassembly code. Reported-by: Xiumei Mu Fixes: 219badfaade9 ("ipv6: frags: get rid of ip6frag_skb_cb/...") Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

ipv6: explicitly initialize udp6_addr in udp_sock_create6()

2018-12-19T20:09:00Z

syzbot reported the use of uninitialized udp6_addr::sin6_scope_id. We can just set ::sin6_scope_id to zero, as tunnels are unlikely to use an IPv6 address that needs a scope id and there is no interface to bind in this context. For net-next, it looks different as we have cfg->bind_ifindex there so we can probably call ipv6_iface_scope_id(). Same for ::sin6_flowinfo, tunnels don't use it. Fixes: 8024e02879dd ("udp: Add udp_sock_create for UDP tunnels to open listener socket") Reported-by: syzbot+c56449ed3652e6720f30@syzkaller.appspotmail.com Cc: Jon Maloy Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net: add missing SOF_TIMESTAMPING_OPT_ID support

2018-12-18T07:27:00Z

SOF_TIMESTAMPING_OPT_ID is supported on TCP, UDP and RAW sockets. But it was missing on RAW with IPPROTO_IP, PF_PACKET and CAN. Add skb_setup_tx_timestamp that configures both tx_flags and tskey for these paths that do not need corking or use bytestream keys. Fixes: 09c2d251b707 ("net-timestamp: add key to disambiguate concurrent datagrams") Signed-off-by: Willem de Bruijn Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

ipv6: add missing tx timestamping on IPPROTO_RAW

2018-12-18T07:27:00Z

Raw sockets support tx timestamping, but one case is missing. IPPROTO_RAW takes a separate packet construction path. raw_send_hdrinc has an explicit call to sock_tx_timestamp, but rawv6_send_hdrinc does not. Add it. Fixes: 11878b40ed5c ("net-timestamp: SOCK_RAW and PING timestamping") Signed-off-by: Willem de Bruijn Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

net: clear skb->tstamp in forwarding paths

2018-12-15T21:24:21Z

Sergey reported that forwarding was no longer working if fq packet scheduler was used. This is caused by the recent switch to EDT model, since incoming packets might have been timestamped by __net_timestamp() __net_timestamp() uses ktime_get_real(), while fq expects packets using CLOCK_MONOTONIC base. The fix is to clear skb->tstamp in forwarding paths. Fixes: 80b14dee2bea ("net: Add a new socket option for a future transmit time.") Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC") Signed-off-by: Eric Dumazet Reported-by: Sergey Matyukevich Tested-by: Sergey Matyukevich Signed-off-by: David S. Miller

ip6mr: Fix potential Spectre v1 vulnerability

2018-12-14T23:34:28Z

vr.mifi is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: net/ipv6/ip6mr.c:1845 ip6mr_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) net/ipv6/ip6mr.c:1919 ip6mr_compat_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) Fix this by sanitizing vr.mifi before using it to index mrt->vif_table' Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller

ipv6: Check available headroom in ip6_xmit() even without options

2018-12-08T00:24:40Z

Even if we send an IPv6 packet without options, MAX_HEADER might not be enough to account for the additional headroom required by alignment of hardware headers. On a configuration without HYPERV_NET, WLAN, AX25, and with IPV6_TUNNEL, sending short SCTP packets over IPv4 over L2TP over IPv6, we start with 100 bytes of allocated headroom in sctp_packet_transmit(), end up with 54 bytes after l2tp_xmit_skb(), and 14 bytes in ip6_finish_output2(). Those would be enough to append our 14 bytes header, but we're going to align that to 16 bytes, and write 2 bytes out of the allocated slab in neigh_hh_output(). KASan says: [ 264.967848] ================================================================== [ 264.967861] BUG: KASAN: slab-out-of-bounds in ip6_finish_output2+0x1aec/0x1c70 [ 264.967866] Write of size 16 at addr 000000006af1c7fe by task netperf/6201 [ 264.967870] [ 264.967876] CPU: 0 PID: 6201 Comm: netperf Not tainted 4.20.0-rc4+ #1 [ 264.967881] Hardware name: IBM 2827 H43 400 (z/VM 6.4.0) [ 264.967887] Call Trace: [ 264.967896] ([<00000000001347d6>] show_stack+0x56/0xa0) [ 264.967903] [<00000000017e379c>] dump_stack+0x23c/0x290 [ 264.967912] [<00000000007bc594>] print_address_description+0xf4/0x290 [ 264.967919] [<00000000007bc8fc>] kasan_report+0x13c/0x240 [ 264.967927] [<000000000162f5e4>] ip6_finish_output2+0x1aec/0x1c70 [ 264.967935] [<000000000163f890>] ip6_finish_output+0x430/0x7f0 [ 264.967943] [<000000000163fe44>] ip6_output+0x1f4/0x580 [ 264.967953] [<000000000163882a>] ip6_xmit+0xfea/0x1ce8 [ 264.967963] [<00000000017396e2>] inet6_csk_xmit+0x282/0x3f8 [ 264.968033] [<000003ff805fb0ba>] l2tp_xmit_skb+0xe02/0x13e0 [l2tp_core] [ 264.968037] [<000003ff80631192>] l2tp_eth_dev_xmit+0xda/0x150 [l2tp_eth] [ 264.968041] [<0000000001220020>] dev_hard_start_xmit+0x268/0x928 [ 264.968069] [<0000000001330e8e>] sch_direct_xmit+0x7ae/0x1350 [ 264.968071] [<000000000122359c>] __dev_queue_xmit+0x2b7c/0x3478 [ 264.968075] [<00000000013d2862>] ip_finish_output2+0xce2/0x11a0 [ 264.968078] [<00000000013d9b14>] ip_finish_output+0x56c/0x8c8 [ 264.968081] [<00000000013ddd1e>] ip_output+0x226/0x4c0 [ 264.968083] [<00000000013dbd6c>] __ip_queue_xmit+0x894/0x1938 [ 264.968100] [<000003ff80bc3a5c>] sctp_packet_transmit+0x29d4/0x3648 [sctp] [ 264.968116] [<000003ff80b7bf68>] sctp_outq_flush_ctrl.constprop.5+0x8d0/0xe50 [sctp] [ 264.968131] [<000003ff80b7c716>] sctp_outq_flush+0x22e/0x7d8 [sctp] [ 264.968146] [<000003ff80b35c68>] sctp_cmd_interpreter.isra.16+0x530/0x6800 [sctp] [ 264.968161] [<000003ff80b3410a>] sctp_do_sm+0x222/0x648 [sctp] [ 264.968177] [<000003ff80bbddac>] sctp_primitive_ASSOCIATE+0xbc/0xf8 [sctp] [ 264.968192] [<000003ff80b93328>] __sctp_connect+0x830/0xc20 [sctp] [ 264.968208] [<000003ff80bb11ce>] sctp_inet_connect+0x2e6/0x378 [sctp] [ 264.968212] [<0000000001197942>] __sys_connect+0x21a/0x450 [ 264.968215] [<000000000119aff8>] sys_socketcall+0x3d0/0xb08 [ 264.968218] [<000000000184ea7a>] system_call+0x2a2/0x2c0 [...] Just like ip_finish_output2() does for IPv4, check that we have enough headroom in ip6_xmit(), and reallocate it if we don't. This issue is older than git history. Reported-by: Jianlin Shi Signed-off-by: Stefano Brivio Signed-off-by: David S. Miller

ipv6: sr: properly initialize flowi6 prior passing to ip6_route_output

2018-12-07T20:22:39Z

In 'seg6_output', stack variable 'struct flowi6 fl6' was missing initialization. Fixes: 6c8702c60b88 ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels") Signed-off-by: Shmulik Ladkani Signed-off-by: David S. Miller

ipv4: ipv6: netfilter: Adjust the frag mem limit when truesize changes

2018-12-06T04:44:46Z

The *_frag_reasm() functions are susceptible to miscalculating the byte count of packet fragments in case the truesize of a head buffer changes. The truesize member may be changed by the call to skb_unclone(), leaving the fragment memory limit counter unbalanced even if all fragments are processed. This miscalculation goes unnoticed as long as the network namespace which holds the counter is not destroyed. Should an attempt be made to destroy a network namespace that holds an unbalanced fragment memory limit counter the cleanup of the namespace never finishes. The thread handling the cleanup gets stuck in inet_frags_exit_net() waiting for the percpu counter to reach zero. The thread is usually in running state with a stacktrace similar to: PID: 1073 TASK: ffff880626711440 CPU: 1 COMMAND: "kworker/u48:4" #5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480 #6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b #7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c #8 [ffff880621563db0] ops_exit_list at ffffffff814f5856 #9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0 #10 [ffff880621563e38] process_one_work at ffffffff81096f14 It is not possible to create new network namespaces, and processes that call unshare() end up being stuck in uninterruptible sleep state waiting to acquire the net_mutex. The bug was observed in the IPv6 netfilter code by Per Sundstrom. I thank him for his analysis of the problem. The parts of this patch that apply to IPv4 and IPv6 fragment reassembly are preemptive measures. Signed-off-by: Jiri Wiesner Reported-by: Per Sundstrom Acked-by: Peter Oskolkov Signed-off-by: David S. Miller