linux/net/ipv6, branch v4.11

ipv6: check raw payload size correctly in ioctl

2017-04-26T18:59:35Z

In situations where an skb is paged, the transport header pointer and tail pointer can be the same because the skb contents are in frags. This results in ioctl(SIOCINQ/FIONREAD) incorrectly returning a length of 0 when the length to receive is actually greater than zero. skb->len is already correctly set in ip6_input_finish() with pskb_pull(), so use skb->len as it always returns the correct result for both linear and paged data. Signed-off-by: Jamie Bainbridge Signed-off-by: David S. Miller

ipv6: check skb->protocol before lookup for nexthop

2017-04-26T18:51:26Z

Andrey reported a out-of-bound access in ip6_tnl_xmit(), this is because we use an ipv4 dst in ip6_tnl_xmit() and cast an IPv4 neigh key as an IPv6 address: neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr); if (!neigh) goto tx_err_link_failure; addr6 = (struct in6_addr *)&neigh->primary_key; // <=== HERE addr_type = ipv6_addr_type(addr6); if (addr_type == IPV6_ADDR_ANY) addr6 = &ipv6_hdr(skb)->daddr; memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr)); Also the network header of the skb at this point should be still IPv4 for 4in6 tunnels, we shold not just use it as IPv6 header. This patch fixes it by checking if skb->protocol is ETH_P_IPV6: if it is, we are safe to do the nexthop lookup using skb_dst() and ipv6_hdr(skb)->daddr; if not (aka IPv4), we have no clue about which dest address we can pick here, we have to rely on callers to fill it from tunnel config, so just fall to ip6_route_output() to make the decision. Fixes: ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel endpoints.") Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Cc: Steffen Klassert Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net: ipv6: regenerate host route if moved to gc list

2017-04-25T18:04:44Z

Taking down the loopback device wreaks havoc on IPv6 routing. By extension, taking down a VRF device wreaks havoc on its table. Dmitry and Andrey both reported heap out-of-bounds reports in the IPv6 FIB code while running syzkaller fuzzer. The root cause is a dead dst that is on the garbage list gets reinserted into the IPv6 FIB. While on the gc (or perhaps when it gets added to the gc list) the dst->next is set to an IPv4 dst. A subsequent walk of the ipv6 tables causes the out-of-bounds access. Andrey's reproducer was the key to getting to the bottom of this. With IPv6, host routes for an address have the dst->dev set to the loopback device. When the 'lo' device is taken down, rt6_ifdown initiates a walk of the fib evicting routes with the 'lo' device which means all host routes are removed. That process moves the dst which is attached to an inet6_ifaddr to the gc list and marks it as dead. The recent change to keep global IPv6 addresses added a new function, fixup_permanent_addr, that is called on admin up. That function restarts dad for an inet6_ifaddr and when it completes the host route attached to it is inserted into the fib. Since the route was marked dead and moved to the gc list, re-inserting the route causes the reported out-of-bounds accesses. If the device with the address is taken down or the address is removed, the WARN_ON in fib6_del is triggered. All of those faults are fixed by regenerating the host route if the existing one has been moved to the gc list, something that can be determined by checking if the rt6i_ref counter is 0. Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional") Reported-by: Dmitry Vyukov Reported-by: Andrey Konovalov Signed-off-by: David Ahern Acked-by: Martin KaFai Lau Acked-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: fix source routing

2017-04-25T17:59:24Z

Commit a149e7c7ce81 ("ipv6: sr: add support for SRH injection through setsockopt") introduced handling of IPV6_SRCRT_TYPE_4, but at the same time restricted it to only IPV6_SRCRT_TYPE_0 and IPV6_SRCRT_TYPE_4. Previously, ipv6_push_exthdr() and fl6_update_dst() would also handle other values (ie STRICT and TYPE_2). Restore previous source routing behavior, by handling IPV6_SRCRT_STRICT and IPV6_SRCRT_TYPE_2 the same way as IPV6_SRCRT_TYPE_0 in ipv6_push_exthdr() and fl6_update_dst(). Fixes: a149e7c7ce81 ("ipv6: sr: add support for SRH injection through setsockopt") Signed-off-by: Sabrina Dubroca Reviewed-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

ipv6: move stub initialization after ipv6 setup completion

2017-04-25T15:43:16Z

The ipv6 stub pointer is currently initialized before the ipv6 routing subsystem: a 3rd party can access and use such stub before the routing data is ready. Moreover, such pointer is not cleared in case of initialization error, possibly leading to dangling pointers usage. This change addresses the above moving the stub initialization at the end of ipv6 init code. Fixes: 5f81bd2e5d80 ("ipv6: export a stub for IPv6 symbols used by vxlan") Signed-off-by: Paolo Abeni Acked-by: Cong Wang Signed-off-by: David S. Miller

net: ipv6: send unsolicited NA if enabled for all interfaces

2017-04-24T18:07:18Z

When arp_notify is set to 1 for either a specific interface or for 'all' interfaces, gratuitous arp requests are sent. Since ndisc_notify is the ipv6 equivalent to arp_notify, it should follow the same semantics. Commit 4a6e3c5def13 ("net: ipv6: send unsolicited NA on admin up") sends the NA on admin up. The final piece is checking devconf_all->ndisc_notify in addition to the per device setting. Add it. Fixes: 5cb04436eef6 ("ipv6: add knob to send unsolicited ND on link-layer address change") Signed-off-by: David Ahern Reviewed-by: Simon Horman Signed-off-by: David S. Miller

ip6mr: fix notification device destruction

2017-04-21T19:35:47Z

Andrey Konovalov reported a BUG caused by the ip6mr code which is caused because we call unregister_netdevice_many for a device that is already being destroyed. In IPv4's ipmr that has been resolved by two commits long time ago by introducing the "notify" parameter to the delete function and avoiding the unregister when called from a notifier, so let's do the same for ip6mr. The trace from Andrey: ------------[ cut here ]------------ kernel BUG at net/core/dev.c:6813! invalid opcode: 0000 [#1] SMP KASAN Modules linked in: CPU: 1 PID: 1165 Comm: kworker/u4:3 Not tainted 4.11.0-rc7+ #251 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: netns cleanup_net task: ffff880069208000 task.stack: ffff8800692d8000 RIP: 0010:rollback_registered_many+0x348/0xeb0 net/core/dev.c:6813 RSP: 0018:ffff8800692de7f0 EFLAGS: 00010297 RAX: ffff880069208000 RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88006af90569 RBP: ffff8800692de9f0 R08: ffff8800692dec60 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000000 R12: ffff88006af90070 R13: ffff8800692debf0 R14: dffffc0000000000 R15: ffff88006af90000 FS: 0000000000000000(0000) GS:ffff88006cb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe7e897d870 CR3: 00000000657e7000 CR4: 00000000000006e0 Call Trace: unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881 unregister_netdevice_many+0xc8/0x120 net/core/dev.c:7880 ip6mr_device_event+0x362/0x3f0 net/ipv6/ip6mr.c:1346 notifier_call_chain+0x145/0x2f0 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1647 call_netdevice_notifiers net/core/dev.c:1663 rollback_registered_many+0x919/0xeb0 net/core/dev.c:6841 unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881 unregister_netdevice_many net/core/dev.c:7880 default_device_exit_batch+0x4fa/0x640 net/core/dev.c:8333 ops_exit_list.isra.4+0x100/0x150 net/core/net_namespace.c:144 cleanup_net+0x5a8/0xb40 net/core/net_namespace.c:463 process_one_work+0xc04/0x1c10 kernel/workqueue.c:2097 worker_thread+0x223/0x19c0 kernel/workqueue.c:2231 kthread+0x35e/0x430 kernel/kthread.c:231 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 Code: 3c 32 00 0f 85 70 0b 00 00 48 b8 00 02 00 00 00 00 ad de 49 89 47 78 e9 93 fe ff ff 49 8d 57 70 49 8d 5f 78 eb 9e e8 88 7a 14 fe <0f> 0b 48 8b 9d 28 fe ff ff e8 7a 7a 14 fe 48 b8 00 00 00 00 00 RIP: rollback_registered_many+0x348/0xeb0 RSP: ffff8800692de7f0 ---[ end trace e0b29c57e9b3292c ]--- Reported-by: Andrey Konovalov Signed-off-by: Nikolay Aleksandrov Tested-by: Andrey Konovalov Signed-off-by: David S. Miller

net: ipv6: RTF_PCPU should not be settable from userspace

2017-04-21T17:55:33Z

Andrey reported a fault in the IPv6 route code: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Modules linked in: CPU: 1 PID: 4035 Comm: a.out Not tainted 4.11.0-rc7+ #250 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff880069809600 task.stack: ffff880062dc8000 RIP: 0010:ip6_rt_cache_alloc+0xa6/0x560 net/ipv6/route.c:975 RSP: 0018:ffff880062dced30 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff8800670561c0 RCX: 0000000000000006 RDX: 0000000000000003 RSI: ffff880062dcfb28 RDI: 0000000000000018 RBP: ffff880062dced68 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff880062dcfb28 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007feebe37e7c0(0000) GS:ffff88006cb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000205a0fe4 CR3: 000000006b5c9000 CR4: 00000000000006e0 Call Trace: ip6_pol_route+0x1512/0x1f20 net/ipv6/route.c:1128 ip6_pol_route_output+0x4c/0x60 net/ipv6/route.c:1212 ... Andrey's syzkaller program passes rtmsg.rtmsg_flags with the RTF_PCPU bit set. Flags passed to the kernel are blindly copied to the allocated rt6_info by ip6_route_info_create making a newly inserted route appear as though it is a per-cpu route. ip6_rt_cache_alloc sees the flag set and expects rt->dst.from to be set - which it is not since it is not really a per-cpu copy. The subsequent call to __ip6_dst_alloc then generates the fault. Fix by checking for the flag and failing with EINVAL. Fixes: d52d3997f843f ("ipv6: Create percpu rt6_info") Reported-by: Andrey Konovalov Signed-off-by: David Ahern Acked-by: Martin KaFai Lau Tested-by: Andrey Konovalov Signed-off-by: David S. Miller

ipv6: sr: fix double free of skb after handling invalid SRH

2017-04-21T17:16:01Z

The icmpv6_param_prob() function already does a kfree_skb(), this patch removes the duplicate one. Fixes: 1ababeba4a21f3dba3da3523c670b207fb2feb62 ("ipv6: implement dataplane support for rthdr type 4 (Segment Routing Header)") Reported-by: Dan Carpenter Cc: Dan Carpenter Signed-off-by: David Lebrun Signed-off-by: David S. Miller

ipv6: sr: fix out-of-bounds access in SRH validation

2017-04-20T19:40:33Z

This patch fixes an out-of-bounds access in seg6_validate_srh() when the trailing data is less than sizeof(struct sr6_tlv). Reported-by: Andrey Konovalov Cc: Andrey Konovalov Signed-off-by: David Lebrun Signed-off-by: David S. Miller