summaryrefslogtreecommitdiff
path: root/net/ipv6
AgeCommit message (Collapse)AuthorFilesLines
2018-11-04net/ipv6: Allow onlink routes to have a device mismatch if it is the default ↵David Ahern1-0/+2
route [ Upstream commit 4ed591c8ab44e711e56b8e021ffaf4f407c045f5 ] The intent of ip6_route_check_nh_onlink is to make sure the gateway given for an onlink route is not actually on a connected route for a different interface (e.g., 2001:db8:1::/64 is on dev eth1 and then an onlink route has a via 2001:db8:1::1 dev eth2). If the gateway lookup hits the default route then it most likely will be a different interface than the onlink route which is ok. Update ip6_route_check_nh_onlink to disregard the device mismatch if the gateway lookup hits the default route. Turns out the existing onlink tests are passing because there is no default route or it is an unreachable default, so update the onlink tests to have a default route other than unreachable. Fixes: fc1e64e1092f6 ("net/ipv6: Add support for onlink flag") Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04ip6_tunnel: Fix encapsulation layoutStefano Brivio1-4/+5
[ Upstream commit d4d576f5ab7edcb757bb33e6a5600666a0b1232d ] Commit 058214a4d1df ("ip6_tun: Add infrastructure for doing encapsulation") added the ip6_tnl_encap() call in ip6_tnl_xmit(), before the call to ipv6_push_frag_opts() to append the IPv6 Tunnel Encapsulation Limit option (option 4, RFC 2473, par. 5.1) to the outer IPv6 header. As long as the option didn't actually end up in generated packets, this wasn't an issue. Then commit 89a23c8b528b ("ip6_tunnel: Fix missing tunnel encapsulation limit option") fixed sending of this option, and the resulting layout, e.g. for FoU, is: .-------------------.------------.----------.-------------------.----- - - | Outer IPv6 Header | UDP header | Option 4 | Inner IPv6 Header | Payload '-------------------'------------'----------'-------------------'----- - - Needless to say, FoU and GUE (at least) won't work over IPv6. The option is appended by default, and I couldn't find a way to disable it with the current iproute2. Turn this into a more reasonable: .-------------------.----------.------------.-------------------.----- - - | Outer IPv6 Header | Option 4 | UDP header | Inner IPv6 Header | Payload '-------------------'----------'------------'-------------------'----- - - With this, and with 84dad55951b0 ("udp6: fix encap return code for resubmitting"), FoU and GUE work again over IPv6. Fixes: 058214a4d1df ("ip6_tun: Add infrastructure for doing encapsulation") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04udp6: fix encap return code for resubmittingPaolo Abeni1-4/+2
[ Upstream commit 84dad55951b0d009372ec21760b650634246e144 ] The commit eb63f2964dbe ("udp6: add missing checks on edumux packet processing") used the same return code convention of the ipv4 counterpart, but ipv6 uses the opposite one: positive values means resubmit. This change addresses the issue, using positive return value for resubmitting. Also update the related comment, which was broken, too. Fixes: eb63f2964dbe ("udp6: add missing checks on edumux packet processing") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04net: udp: fix handling of CHECKSUM_COMPLETE packetsSean Tranchetti1-2/+18
[ Upstream commit db4f1be3ca9b0ef7330763d07bf4ace83ad6f913 ] Current handling of CHECKSUM_COMPLETE packets by the UDP stack is incorrect for any packet that has an incorrect checksum value. udp4/6_csum_init() will both make a call to __skb_checksum_validate_complete() to initialize/validate the csum field when receiving a CHECKSUM_COMPLETE packet. When this packet fails validation, skb->csum will be overwritten with the pseudoheader checksum so the packet can be fully validated by software, but the skb->ip_summed value will be left as CHECKSUM_COMPLETE so that way the stack can later warn the user about their hardware spewing bad checksums. Unfortunately, leaving the SKB in this state can cause problems later on in the checksum calculation. Since the the packet is still marked as CHECKSUM_COMPLETE, udp_csum_pull_header() will SUBTRACT the checksum of the UDP header from skb->csum instead of adding it, leaving us with a garbage value in that field. Once we try to copy the packet to userspace in the udp4/6_recvmsg(), we'll make a call to skb_copy_and_csum_datagram_msg() to checksum the packet data and add it in the garbage skb->csum value to perform our final validation check. Since the value we're validating is not the proper checksum, it's possible that the folded value could come out to 0, causing us not to drop the packet. Instead, we believe that the packet was checksummed incorrectly by hardware since skb->ip_summed is still CHECKSUM_COMPLETE, and we attempt to warn the user with netdev_rx_csum_fault(skb->dev); Unfortunately, since this is the UDP path, skb->dev has been overwritten by skb->dev_scratch and is no longer a valid pointer, so we end up reading invalid memory. This patch addresses this problem in two ways: 1) Do not use the dev pointer when calling netdev_rx_csum_fault() from skb_copy_and_csum_datagram_msg(). Since this gets called from the UDP path where skb->dev has been overwritten, we have no way of knowing if the pointer is still valid. Also for the sake of consistency with the other uses of netdev_rx_csum_fault(), don't attempt to call it if the packet was checksummed by software. 2) Add better CHECKSUM_COMPLETE handling to udp4/6_csum_init(). If we receive a packet that's CHECKSUM_COMPLETE that fails verification (i.e. skb->csum_valid == 0), check who performed the calculation. It's possible that the checksum was done in software by the network stack earlier (such as Netfilter's CONNTRACK module), and if that says the checksum is bad, we can drop the packet immediately instead of waiting until we try and copy it to userspace. Otherwise, we need to mark the SKB as CHECKSUM_NONE, since the skb->csum field no longer contains the full packet checksum after the call to __skb_checksum_validate_complete(). Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") Fixes: c84d949057ca ("udp: copy skb->truesize in the first cache line") Cc: Sam Kumar <samanthakumar@google.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Sean Tranchetti <stranche@codeaurora.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04net/ipv6: Fix index counter for unicast addresses in in6_dump_addrsDavid Ahern1-2/+4
[ Upstream commit 4ba4c566ba8448a05e6257e0b98a21f1a0d55315 ] The loop wants to skip previously dumped addresses, so loops until current index >= saved index. If the message fills it wants to save the index for the next address to dump - ie., the one that did not fit in the current message. Currently, it is incrementing the index counter before comparing to the saved index, and then the saved index is off by 1 - it assumes the current address is going to fit in the message. Change the index handling to increment only after a succesful dump. Fixes: 502a2ffd7376a ("ipv6: convert idev_list to list macros") Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04ipv6: rate-limit probes for neighbourless routesSabrina Dubroca1-6/+6
[ Upstream commit f547fac624be53ad8b07e9ebca7654a7827ba61b ] When commit 270972554c91 ("[IPV6]: ROUTE: Add Router Reachability Probing (RFC4191).") introduced router probing, the rt6_probe() function required that a neighbour entry existed. This neighbour entry is used to record the timestamp of the last probe via the ->updated field. Later, commit 2152caea7196 ("ipv6: Do not depend on rt->n in rt6_probe().") removed the requirement for a neighbour entry. Neighbourless routes skip the interval check and are not rate-limited. This patch adds rate-limiting for neighbourless routes, by recording the timestamp of the last probe in the fib6_info itself. Fixes: 2152caea7196 ("ipv6: Do not depend on rt->n in rt6_probe().") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04ipv6/ndisc: Preserve IPv6 control buffer if protocol error handlers are calledStefano Brivio1-2/+1
[ Upstream commit ee1abcf689353f36d9322231b4320926096bdee0 ] Commit a61bbcf28a8c ("[NET]: Store skb->timestamp as offset to a base timestamp") introduces a neighbour control buffer and zeroes it out in ndisc_rcv(), as ndisc_recv_ns() uses it. Commit f2776ff04722 ("[IPV6]: Fix address/interface handling in UDP and DCCP, according to the scoping architecture.") introduces the usage of the IPv6 control buffer in protocol error handlers (e.g. inet6_iif() in present-day __udp6_lib_err()). Now, with commit b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect()."), we call protocol error handlers from ndisc_redirect_rcv(), after the control buffer is already stolen and some parts are already zeroed out. This implies that inet6_iif() on this path will always return zero. This gives unexpected results on UDP socket lookup in __udp6_lib_err(), as we might actually need to match sockets for a given interface. Instead of always claiming the control buffer in ndisc_rcv(), do that only when needed. Fixes: b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect().") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04ipv6: mcast: fix a use-after-free in inet6_mc_checkEric Dumazet1-8/+8
[ Upstream commit dc012f3628eaecfb5ba68404a5c30ef501daf63d ] syzbot found a use-after-free in inet6_mc_check [1] The problem here is that inet6_mc_check() uses rcu and read_lock(&iml->sflock) So the fact that ip6_mc_leave_src() is called under RTNL and the socket lock does not help us, we need to acquire iml->sflock in write mode. In the future, we should convert all this stuff to RCU. [1] BUG: KASAN: use-after-free in ipv6_addr_equal include/net/ipv6.h:521 [inline] BUG: KASAN: use-after-free in inet6_mc_check+0xae7/0xb40 net/ipv6/mcast.c:649 Read of size 8 at addr ffff8801ce7f2510 by task syz-executor0/22432 CPU: 1 PID: 22432 Comm: syz-executor0 Not tainted 4.19.0-rc7+ #280 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+0x1c4/0x2b4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 ipv6_addr_equal include/net/ipv6.h:521 [inline] inet6_mc_check+0xae7/0xb40 net/ipv6/mcast.c:649 __raw_v6_lookup+0x320/0x3f0 net/ipv6/raw.c:98 ipv6_raw_deliver net/ipv6/raw.c:183 [inline] raw6_local_deliver+0x3d3/0xcb0 net/ipv6/raw.c:240 ip6_input_finish+0x467/0x1aa0 net/ipv6/ip6_input.c:345 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:426 ip6_mc_input+0x48a/0xd20 net/ipv6/ip6_input.c:503 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+0x120/0x640 net/ipv6/ip6_input.c:271 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4913 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5023 netif_receive_skb_internal+0x12c/0x620 net/core/dev.c:5126 napi_frags_finish net/core/dev.c:5664 [inline] napi_gro_frags+0x75a/0xc90 net/core/dev.c:5737 tun_get_user+0x3189/0x4250 drivers/net/tun.c:1923 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1968 call_write_iter include/linux/fs.h:1808 [inline] do_iter_readv_writev+0x8b0/0xa80 fs/read_write.c:680 do_iter_write+0x185/0x5f0 fs/read_write.c:959 vfs_writev+0x1f1/0x360 fs/read_write.c:1004 do_writev+0x11a/0x310 fs/read_write.c:1039 __do_sys_writev fs/read_write.c:1112 [inline] __se_sys_writev fs/read_write.c:1109 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1109 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457421 Code: 75 14 b8 14 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 34 b5 fb ff c3 48 83 ec 08 e8 1a 2d 00 00 48 89 04 24 b8 14 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 63 2d 00 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f2d30ecaba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000000003e RCX: 0000000000457421 RDX: 0000000000000001 RSI: 00007f2d30ecabf0 RDI: 00000000000000f0 RBP: 0000000020000500 R08: 00000000000000f0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f2d30ecb6d4 R13: 00000000004c4890 R14: 00000000004d7b90 R15: 00000000ffffffff Allocated by task 22437: 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 mm/slab.c:3718 [inline] __kmalloc+0x14e/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:518 [inline] sock_kmalloc+0x15a/0x1f0 net/core/sock.c:1983 ip6_mc_source+0x14dd/0x1960 net/ipv6/mcast.c:427 do_ipv6_setsockopt.isra.9+0x3afb/0x45d0 net/ipv6/ipv6_sockglue.c:743 ipv6_setsockopt+0xbd/0x170 net/ipv6/ipv6_sockglue.c:933 rawv6_setsockopt+0x59/0x140 net/ipv6/raw.c:1069 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 __do_sys_setsockopt net/socket.c:1913 [inline] __se_sys_setsockopt net/socket.c:1910 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 22430: 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:3813 __sock_kfree_s net/core/sock.c:2004 [inline] sock_kfree_s+0x29/0x60 net/core/sock.c:2010 ip6_mc_leave_src+0x11a/0x1d0 net/ipv6/mcast.c:2448 __ipv6_sock_mc_close+0x20b/0x4e0 net/ipv6/mcast.c:310 ipv6_sock_mc_close+0x158/0x1d0 net/ipv6/mcast.c:328 inet6_release+0x40/0x70 net/ipv6/af_inet6.c:452 __sock_release+0xd7/0x250 net/socket.c:579 sock_close+0x19/0x20 net/socket.c:1141 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801ce7f2500 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 16 bytes inside of 192-byte region [ffff8801ce7f2500, ffff8801ce7f25c0) The buggy address belongs to the page: page:ffffea000739fc80 count:1 mapcount:0 mapping:ffff8801da800040 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0006f6e548 ffffea000737b948 ffff8801da800040 raw: 0000000000000000 ffff8801ce7f2000 0000000100000010 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801ce7f2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ce7f2480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801ce7f2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801ce7f2580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801ce7f2600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-04Revert "netfilter: ipv6: nf_defrag: drop skb dst before queueing"Sasha Levin1-2/+0
This reverts commit 84379c9afe011020e797e3f50a662b08a6355dcf. From Florian Westphal <fw@strlen.de>: It causes kernel crash for locally generated ipv6 fragments when netfilter ipv6 defragmentation is used. The faulty commit is not essential for -stable, it only delays netns teardown for longer than needed when that netns still has ipv6 frags queued. Much better than crash :-/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-04xfrm: reset transport header back to network header after all input ↵Sowmini Varadhan2-3/+2
transforms ahave been applied [ Upstream commit bfc0698bebcb16d19ecfc89574ad4d696955e5d3 ] A policy may have been set up with multiple transforms (e.g., ESP and ipcomp). In this situation, the ingress IPsec processing iterates in xfrm_input() and applies each transform in turn, processing the nexthdr to find any additional xfrm that may apply. This patch resets the transport header back to network header only after the last transformation so that subsequent xfrms can find the correct transport header. Fixes: 7785bba299a8 ("esp: Add a software GRO codepath") Suggested-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-11-04xfrm6: call kfree_skb when skb is toobigThadeu Lima de Souza Cascardo1-0/+2
[ Upstream commit 215ab0f021c9fea3c18b75e7d522400ee6a49990 ] After commit d6990976af7c5d8f55903bfb4289b6fb030bf754 ("vti6: fix PMTU caching and reporting on xmit"), some too big skbs might be potentially passed down to __xfrm6_output, causing it to fail to transmit but not free the skb, causing a leak of skb, and consequentially a leak of dst references. After running pmtu.sh, that shows as failure to unregister devices in a namespace: [ 311.397671] unregister_netdevice: waiting for veth_b to become free. Usage count = 1 The fix is to call kfree_skb in case of transmit failures. Fixes: dd767856a36e ("xfrm6: Don't call icmpv6_send on local error") Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-10-18net/ipv6: stop leaking percpu memory in fib6 infoMike Rapoport1-0/+2
[ Upstream commit 7abab7b9b498650404800a08765f44929fee8f31 ] The fib6_info_alloc() function allocates percpu memory to hold per CPU pointers to rt6_info, but this memory is never freed. Fix it. Fixes: a64efe142f5e ("net/ipv6: introduce fib6_info struct and helpers") Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18net/ipv6: Remove extra call to ip6_convert_metrics for multipath caseDavid Ahern1-5/+0
[ Upstream commit 36f19d5b4f99fa9fa8263877e5f8e669d7fddc14 ] The change to move metrics from the dst to rt6_info moved the call to ip6_convert_metrics from ip6_route_add to ip6_route_info_create. In doing so it makes the call in ip6_route_info_append redundant and actually leaks the metrics installed as part of the ip6_route_info_create. Remove the now unnecessary call. Fixes: d4ead6b34b67f ("net/ipv6: move metrics from dst to rt6_info") Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18net/ipv6: Display all addresses in output of /proc/net/if_inet6Jeff Barnhill1-3/+1
[ Upstream commit 86f9bd1ff61c413a2a251fa736463295e4e24733 ] The backend handling for /proc/net/if_inet6 in addrconf.c doesn't properly handle starting/stopping the iteration. The problem is that at some point during the iteration, an overflow is detected and the process is subsequently stopped. The item being shown via seq_printf() when the overflow occurs is not actually shown, though. When start() is subsequently called to resume iterating, it returns the next item, and thus the item that was being processed when the overflow occurred never gets printed. Alter the meaning of the private data member "offset". Currently, when it is not 0 (which only happens at the very beginning), "offset" represents the next hlist item to be printed. After this change, "offset" always represents the current item. This is also consistent with the private data member "bucket", which represents the current bucket, and also the use of "pos" as defined in seq_file.txt: The pos passed to start() will always be either zero, or the most recent pos used in the previous session. Signed-off-by: Jeff Barnhill <0xeffeff@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ipv6: take rcu lock in rawv6_send_hdrinc()Wei Wang1-9/+20
[ Upstream commit a688caa34beb2fd2a92f1b6d33e40cde433ba160 ] In rawv6_send_hdrinc(), in order to avoid an extra dst_hold(), we directly assign the dst to skb and set passed in dst to NULL to avoid double free. However, in error case, we free skb and then do stats update with the dst pointer passed in. This causes use-after-free on the dst. Fix it by taking rcu read lock right before dst could get released to make sure dst does not get freed until the stats update is done. Note: we don't have this issue in ipv4 cause dst is not used for stats update in v4. Syzkaller reported following crash: BUG: KASAN: use-after-free in rawv6_send_hdrinc net/ipv6/raw.c:692 [inline] BUG: KASAN: use-after-free in rawv6_sendmsg+0x4421/0x4630 net/ipv6/raw.c:921 Read of size 8 at addr ffff8801d95ba730 by task syz-executor0/32088 CPU: 1 PID: 32088 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #93 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+0x1c4/0x2b4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 rawv6_send_hdrinc net/ipv6/raw.c:692 [inline] rawv6_sendmsg+0x4421/0x4630 net/ipv6/raw.c:921 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:2114 __sys_sendmsg+0x11d/0x280 net/socket.c:2152 __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg net/socket.c:2159 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457099 Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f83756edc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f83756ee6d4 RCX: 0000000000457099 RDX: 0000000000000000 RSI: 0000000020003840 RDI: 0000000000000004 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d4b30 R14: 00000000004c90b1 R15: 0000000000000000 Allocated by task 32088: 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 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 dst_alloc+0xbb/0x1d0 net/core/dst.c:105 ip6_dst_alloc+0x35/0xa0 net/ipv6/route.c:353 ip6_rt_cache_alloc+0x247/0x7b0 net/ipv6/route.c:1186 ip6_pol_route+0x8f8/0xd90 net/ipv6/route.c:1895 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2093 fib6_rule_lookup+0x277/0x860 net/ipv6/fib6_rules.c:122 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2121 ip6_route_output include/net/ip6_route.h:88 [inline] ip6_dst_lookup_tail+0xe27/0x1d60 net/ipv6/ip6_output.c:951 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079 rawv6_sendmsg+0x12d9/0x4630 net/ipv6/raw.c:905 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:2114 __sys_sendmsg+0x11d/0x280 net/socket.c:2152 __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg net/socket.c:2159 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 5356: 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] kmem_cache_free+0x83/0x290 mm/slab.c:3756 dst_destroy+0x267/0x3c0 net/core/dst.c:141 dst_destroy_rcu+0x16/0x19 net/core/dst.c:154 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 Fixes: 1789a640f556 ("raw: avoid two atomics in xmit") Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18ip6_tunnel: be careful when accessing the inner headerPaolo Abeni1-2/+11
[ Upstream commit 76c0ddd8c3a683f6e2c6e60e11dc1a1558caf4bc ] the ip6 tunnel xmit ndo assumes that the processed skb always contains an ip[v6] header, but syzbot has found a way to send frames that fall short of this assumption, leading to the following splat: BUG: KMSAN: uninit-value in ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1307 [inline] BUG: KMSAN: uninit-value in ip6_tnl_start_xmit+0x7d2/0x1ef0 net/ipv6/ip6_tunnel.c:1390 CPU: 0 PID: 4504 Comm: syz-executor558 Not tainted 4.16.0+ #87 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1307 [inline] ip6_tnl_start_xmit+0x7d2/0x1ef0 net/ipv6/ip6_tunnel.c:1390 __netdev_start_xmit include/linux/netdevice.h:4066 [inline] netdev_start_xmit include/linux/netdevice.h:4075 [inline] xmit_one net/core/dev.c:3026 [inline] dev_hard_start_xmit+0x5f1/0xc70 net/core/dev.c:3042 __dev_queue_xmit+0x27ee/0x3520 net/core/dev.c:3557 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590 packet_snd net/packet/af_packet.c:2944 [inline] packet_sendmsg+0x7c70/0x8a30 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmmsg+0x42d/0x800 net/socket.c:2136 SYSC_sendmmsg+0xc4/0x110 net/socket.c:2167 SyS_sendmmsg+0x63/0x90 net/socket.c:2162 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x441819 RSP: 002b:00007ffe58ee8268 EFLAGS: 00000213 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441819 RDX: 0000000000000002 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00000000006cd018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000402510 R13: 00000000004025a0 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slub.c:2737 [inline] __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:984 [inline] alloc_skb_with_frags+0x1d4/0xb20 net/core/skbuff.c:5234 sock_alloc_send_pskb+0xb56/0x1190 net/core/sock.c:2085 packet_alloc_skb net/packet/af_packet.c:2803 [inline] packet_snd net/packet/af_packet.c:2894 [inline] packet_sendmsg+0x6454/0x8a30 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmmsg+0x42d/0x800 net/socket.c:2136 SYSC_sendmmsg+0xc4/0x110 net/socket.c:2167 SyS_sendmmsg+0x63/0x90 net/socket.c:2162 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 This change addresses the issue adding the needed check before accessing the inner header. The ipv4 side of the issue is apparently there since the ipv4 over ipv6 initial support, and the ipv6 side predates git history. Fixes: c4d3efafcc93 ("[IPV6] IP6TUNNEL: Add support to IPv4 over IPv6 tunnel.") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+3fde91d4d394747d6db4@syzkaller.appspotmail.com Tested-by: Alexander Potapenko <glider@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-29net/ipv6: do not copy dst flags on rt initPeter Oskolkov1-2/+0
[ Upstream commit 30bfd93062814d6767e452a8f5ddcd97f7e38c7e ] DST_NOCOUNT in dst_entry::flags tracks whether the entry counts toward route cache size (net->ipv6.sysctl.ip6_rt_max_size). If the flag is NOT set, dst_ops::pcpuc_entries counter is incremented in dist_init() and decremented in dst_destroy(). This flag is tied to allocation/deallocation of dst_entry and should not be copied from another dst/route. Otherwise it can happen that dst_ops::pcpuc_entries counter grows until no new routes can be allocated because the counter reached ip6_rt_max_size due to DST_NOCOUNT not set and thus no counter decrements on gc-ed routes. Fixes: 3b6761d18bc1 ("net/ipv6: Move dst flags to booleans in fib entries") Cc: David Ahern <dsahern@gmail.com> Acked-by: Wei Wang <weiwan@google.com> Signed-off-by: Peter Oskolkov <posk@google.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-29ipv6: use rt6_info members when dst is set in rt6_fill_nodeXin Long1-12/+30
[ Upstream commit 22d0bd82cc7cec7d9ed4bd5913f3ab65643364be ] In inet6_rtm_getroute, since Commit 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes"), it has used rt->from to dump route info instead of rt. However for some route like cache, some of its information like flags or gateway is not the same as that of the 'from' one. It caused 'ip route get' to dump the wrong route information. In Jianlin's testing, the output information even lost the expiration time for a pmtu route cache due to the wrong fib6_flags. So change to use rt6_info members for dst addr, src addr, flags and gateway when it tries to dump a route entry without fibmatch set. v1->v2: - not use rt6i_prefsrc. - also fix the gw dump issue. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-29udp6: add missing checks on edumux packet processingPaolo Abeni1-28/+37
[ Upstream commit eb63f2964dbe36f26deac77d3016791675821ded ] Currently the UDPv6 early demux rx code path lacks some mandatory checks, already implemented into the normal RX code path - namely the checksum conversion and no_check6_rx check. Similar to the previous commit, we move the common processing to an UDPv6 specific helper and call it from both edemux code path and normal code path. In respect to the UDPv4, we need to add an explicit check for non zero csum according to no_check6_rx value. Reported-by: Jianlin Shi <jishi@redhat.com> Suggested-by: Xin Long <lucien.xin@gmail.com> Fixes: c9f2c1ae123a ("udp6: fix socket leak on early demux") Fixes: 2abb7cdc0dc8 ("udp: Add support for doing checksum unnecessary conversion") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-29ipv6: fix possible use-after-free in ip6_xmit()Eric Dumazet1-4/+2
[ Upstream commit bbd6528d28c1b8e80832b3b018ec402b6f5c3215 ] In the unlikely case ip6_xmit() has to call skb_realloc_headroom(), we need to call skb_set_owner_w() before consuming original skb, otherwise we risk a use-after-free. Bring IPv6 in line with what we do in IPv4 to fix this. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-29gso_segment: Reset skb->mac_len after modifying network headerToke Høiland-Jørgensen1-0/+1
[ Upstream commit c56cae23c6b167acc68043c683c4573b80cbcc2c ] When splitting a GSO segment that consists of encapsulated packets, the skb->mac_len of the segments can end up being set wrong, causing packet drops in particular when using act_mirred and ifb interfaces in combination with a qdisc that splits GSO packets. This happens because at the time skb_segment() is called, network_header will point to the inner header, throwing off the calculation in skb_reset_mac_len(). The network_header is subsequently adjust by the outer IP gso_segment handlers, but they don't set the mac_len. Fix this by adding skb_reset_mac_len() calls to both the IPv4 and IPv6 gso_segment handlers, after they modify the network_header. Many thanks to Eric Dumazet for his help in identifying the cause of the bug. Acked-by: Dave Taht <dave.taht@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15netfilter: ip6t_rpfilter: set F_IFACE for linklocal addressesFlorian Westphal1-1/+11
[ Upstream commit da786717e0894886301ed2536843c13f9e8fd53e ] Roman reports that DHCPv6 client no longer sees replies from server due to ip6tables -t raw -A PREROUTING -m rpfilter --invert -j DROP rule. We need to set the F_IFACE flag for linklocal addresses, they are scoped per-device. Fixes: 47b7e7f82802 ("netfilter: don't set F_IFACE on ipv6 fib lookups") Reported-by: Roman Mamedov <rm@romanrm.net> Tested-by: Roman Mamedov <rm@romanrm.net> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15ip6_vti: fix a null pointer deference when destroy vti6 tunnelHaishuang Yan1-1/+2
[ Upstream commit 9c86336c15db1c48cbaddff56caf2be0a930e991 ] If load ip6_vti module and create a network namespace when set fb_tunnels_only_for_init_net to 1, then exit the namespace will cause following crash: [ 6601.677036] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 6601.679057] PGD 8000000425eca067 P4D 8000000425eca067 PUD 424292067 PMD 0 [ 6601.680483] Oops: 0000 [#1] SMP PTI [ 6601.681223] CPU: 7 PID: 93 Comm: kworker/u16:1 Kdump: loaded Tainted: G E 4.18.0+ #3 [ 6601.683153] Hardware name: Fedora Project OpenStack Nova, BIOS seabios-1.7.5-11.el7 04/01/2014 [ 6601.684919] Workqueue: netns cleanup_net [ 6601.685742] RIP: 0010:vti6_exit_batch_net+0x87/0xd0 [ip6_vti] [ 6601.686932] Code: 7b 08 48 89 e6 e8 b9 ea d3 dd 48 8b 1b 48 85 db 75 ec 48 83 c5 08 48 81 fd 00 01 00 00 75 d5 49 8b 84 24 08 01 00 00 48 89 e6 <48> 8b 78 08 e8 90 ea d3 dd 49 8b 45 28 49 39 c6 4c 8d 68 d8 75 a1 [ 6601.690735] RSP: 0018:ffffa897c2737de0 EFLAGS: 00010246 [ 6601.691846] RAX: 0000000000000000 RBX: 0000000000000000 RCX: dead000000000200 [ 6601.693324] RDX: 0000000000000015 RSI: ffffa897c2737de0 RDI: ffffffff9f2ea9e0 [ 6601.694824] RBP: 0000000000000100 R08: 0000000000000000 R09: 0000000000000000 [ 6601.696314] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8dc323c07e00 [ 6601.697812] R13: ffff8dc324a63100 R14: ffffa897c2737e30 R15: ffffa897c2737e30 [ 6601.699345] FS: 0000000000000000(0000) GS:ffff8dc33fdc0000(0000) knlGS:0000000000000000 [ 6601.701068] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6601.702282] CR2: 0000000000000008 CR3: 0000000424966002 CR4: 00000000001606e0 [ 6601.703791] Call Trace: [ 6601.704329] cleanup_net+0x1b4/0x2c0 [ 6601.705268] process_one_work+0x16c/0x370 [ 6601.706145] worker_thread+0x49/0x3e0 [ 6601.706942] kthread+0xf8/0x130 [ 6601.707626] ? rescuer_thread+0x340/0x340 [ 6601.708476] ? kthread_bind+0x10/0x10 [ 6601.709266] ret_from_fork+0x35/0x40 Reproduce: modprobe ip6_vti echo 1 > /proc/sys/net/core/fb_tunnels_only_for_init_net unshare -n exit This because ip6n->tnls_wc[0] point to fallback device in default, but in non-default namespace, ip6n->tnls_wc[0] will be NULL, so add the NULL check comparatively. Fixes: e2948e5af8ee ("ip6_vti: fix creating fallback tunnel device for vti6") Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15ip6_vti: fix creating fallback tunnel device for vti6Haishuang Yan1-0/+2
[ Upstream commit e2948e5af8eeb6c945000772b7613b0323a0a203 ] When set fb_tunnels_only_for_init_net to 1, don't create fallback tunnel device for vti6 when a new namespace is created. Tested: [root@builder2 ~]# modprobe ip6_tunnel [root@builder2 ~]# modprobe ip6_vti [root@builder2 ~]# echo 1 > /proc/sys/net/core/fb_tunnels_only_for_init_net [root@builder2 ~]# unshare -n [root@builder2 ~]# ip link 1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15net/ipv6: Put lwtstate when destroying fib6_infoDavid Ahern1-0/+2
[ Upstream commit 80f1a0f4e0cd4bfc8a74fc1c39843a6e7b206b95 ] Prior to the introduction of fib6_info lwtstate was managed by the dst code. With fib6_info releasing lwtstate needs to be done when the struct is freed. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15net/ipv6: Only update MTU metric if it setDavid Ahern1-1/+4
[ Upstream commit 15a81b418e22a9aa4a0504471fdcb0f4ebf69b96 ] Jan reported a regression after an update to 4.18.5. In this case ipv6 default route is setup by systemd-networkd based on data from an RA. The RA contains an MTU of 1492 which is used when the route is first inserted but then systemd-networkd pushes down updates to the default route without the mtu set. Prior to the change to fib6_info, metrics such as MTU were held in the dst_entry and rt6i_pmtu in rt6_info contained an update to the mtu if any. ip6_mtu would look at rt6i_pmtu first and use it if set. If not, the value from the metrics is used if it is set and finally falling back to the idev value. After the fib6_info change metrics are contained in the fib6_info struct and there is no equivalent to rt6i_pmtu. To maintain consistency with the old behavior the new code should only reset the MTU in the metrics if the route update has it set. Fixes: d4ead6b34b67 ("net/ipv6: move metrics from dst to rt6_info") Reported-by: Jan Janssen <medhefgo@web.de> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15net/ipv6: init ip6 anycast rt->dst.input as ip6_inputHangbin Liu1-1/+1
[ Upstream commit d23c4b6336ef30898dcdff351f21e633e7a64930 ] Commit 6edb3c96a5f02 ("net/ipv6: Defer initialization of dst to data path") forgot to handle anycast route and init anycast rt->dst.input to ip6_forward. Fix it by setting anycast rt->dst.input back to ip6_input. Fixes: 6edb3c96a5f02 ("net/ipv6: Defer initialization of dst to data path") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15ipv6: don't get lwtstate twice in ip6_rt_copy_init()Alexey Kodanev1-1/+0
[ Upstream commit 93bbadd6e0a2a58e49d265b9b1aa58e621b60a26 ] Commit 80f1a0f4e0cd ("net/ipv6: Put lwtstate when destroying fib6_info") partially fixed the kmemleak [1], lwtstate can be copied from fib6_info, with ip6_rt_copy_init(), and it should be done only once there. rt->dst.lwtstate is set by ip6_rt_init_dst(), at the start of the function ip6_rt_copy_init(), so there is no need to get it again at the end. With this patch, lwtstate also isn't copied from RTF_REJECT routes. [1]: unreferenced object 0xffff880b6aaa14e0 (size 64): comm "ip", pid 10577, jiffies 4295149341 (age 1273.903s) hex dump (first 32 bytes): 01 00 04 00 04 00 00 00 10 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000018664623>] lwtunnel_build_state+0x1bc/0x420 [<00000000b73aa29a>] ip6_route_info_create+0x9f7/0x1fd0 [<00000000ee2c5d1f>] ip6_route_add+0x14/0x70 [<000000008537b55c>] inet6_rtm_newroute+0xd9/0xe0 [<000000002acc50f5>] rtnetlink_rcv_msg+0x66f/0x8e0 [<000000008d9cd381>] netlink_rcv_skb+0x268/0x3b0 [<000000004c893c76>] netlink_unicast+0x417/0x5a0 [<00000000f2ab1afb>] netlink_sendmsg+0x70b/0xc30 [<00000000890ff0aa>] sock_sendmsg+0xb1/0xf0 [<00000000a2e7b66f>] ___sys_sendmsg+0x659/0x950 [<000000001e7426c8>] __sys_sendmsg+0xde/0x170 [<00000000fe411443>] do_syscall_64+0x9f/0x4a0 [<000000001be7b28b>] entry_SYSCALL_64_after_hwframe+0x49/0xbe [<000000006d21f353>] 0xffffffffffffffff Fixes: 6edb3c96a5f0 ("net/ipv6: Defer initialization of dst to data path") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15erspan: set erspan_ver to 1 by default when adding an erspan devXin Long1-0/+1
[ Upstream commit 84581bdae9587023cea1d139523f0ef0f28bd88d ] After erspan_ver is introudced, if erspan_ver is not set in iproute, its value will be left 0 by default. Since Commit 02f99df1875c ("erspan: fix invalid erspan version."), it has broken the traffic due to the version check in erspan_xmit if users are not aware of 'erspan_ver' param, like using an old version of iproute. To fix this compatibility problem, it sets erspan_ver to 1 by default when adding an erspan dev in erspan_setup. Note that we can't do it in ipgre_netlink_parms, as this function is also used by ipgre_changelink. Fixes: 02f99df1875c ("erspan: fix invalid erspan version.") Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15vti6: remove !skb->ignore_df check from vti6_xmit()Alexey Kodanev1-1/+1
[ Upstream commit 9f2895461439fda2801a7906fb4c5fb3dbb37a0a ] Before the commit d6990976af7c ("vti6: fix PMTU caching and reporting on xmit") '!skb->ignore_df' check was always true because the function skb_scrub_packet() was called before it, resetting ignore_df to zero. In the commit, skb_scrub_packet() was moved below, and now this check can be false for the packet, e.g. when sending it in the two fragments, this prevents successful PMTU updates in such case. The next attempts to send the packet lead to the same tx error. Moreover, vti6 initial MTU value relies on PMTU adjustments. This issue can be reproduced with the following LTP test script: udp_ipsec_vti.sh -6 -p ah -m tunnel -s 2000 Fixes: ccd740cbc6e0 ("vti6: Add pmtu handling to vti6_xmit.") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06ip6_tunnel: use the right value for ipv4 min mtu check in ip6_tnl_xmitXin Long1-6/+2
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 <sd@queasysnail.net> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-06ipv6: fix double refcount of fib6_metricsCong Wang1-4/+0
All the callers of ip6_rt_copy_init()/rt6_set_from() hold refcnt of the "from" fib6_info, so there is no need to hold fib6_metrics refcnt again, because fib6_metrics refcnt is only released when fib6_info is gone, that is, they have the same life time, so the whole fib6_metrics refcnt can be removed actually. This fixes a kmemleak warning reported by Sabrina. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Reported-by: Sabrina Dubroca <sd@queasysnail.net> Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02Revert "net/ipv6: fix metrics leak"David S. Miller1-14/+4
This reverts commit df18b50448fab1dff093731dfd0e25e77e1afcd1. This change causes other problems and use-after-free situations as found by syzbot. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30net/ipv6: fix metrics leakSabrina Dubroca1-4/+14
Since commit d4ead6b34b67 ("net/ipv6: move metrics from dst to rt6_info"), ipv6 metrics are shared and refcounted. rt6_set_from() assigns the rt->from pointer and increases the refcount on from's metrics. This reference is never released. Introduce the fib6_metrics_release() helper and use it to release the metrics. Fixes: d4ead6b34b67 ("net/ipv6: move metrics from dst to rt6_info") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27Merge branch 'master' of ↵David S. Miller2-6/+9
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2018-07-27 1) Fix PMTU handling of vti6. We update the PMTU on the xfrm dst_entry which is not cached anymore after the flowchache removal. So update the PMTU of the original dst_entry instead. From Eyal Birger. 2) Fix a leak of kernel memory to userspace. From Eric Dumazet. 3) Fix a possible dst_entry memleak in xfrm_lookup_route. From Tommi Rantala. 4) Fix a skb leak in case we can't call nlmsg_multicast from xfrm_nlmsg_multicast. From Florian Westphal. 5) Fix a leak of a temporary buffer in the error path of esp6_input. From Zhen Lei. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-25ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pullWillem de Bruijn1-2/+5
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 <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23ip: hash fragments consistentlyPaolo Abeni1-0/+2
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 <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-23ipv6: use fib6_info_hold_safe() when necessaryWei Wang2-11/+33
In the code path where only rcu read lock is held, e.g. in the route lookup code path, it is not safe to directly call fib6_info_hold() because the fib6_info may already have been deleted but still exists in the rcu grace period. Holding reference to it could cause double free and crash the kernel. This patch adds a new function fib6_info_hold_safe() and replace fib6_info_hold() in all necessary places. Syzbot reported 3 crash traces because of this. One of them is: 8021q: adding VLAN 0 to HW filter on device team0 IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready dst_release: dst:(____ptrval____) refcnt:-1 dst_release: dst:(____ptrval____) refcnt:-2 WARNING: CPU: 1 PID: 4845 at include/net/dst.h:239 dst_hold include/net/dst.h:239 [inline] WARNING: CPU: 1 PID: 4845 at include/net/dst.h:239 ip6_setup_cork+0xd66/0x1830 net/ipv6/ip6_output.c:1204 dst_release: dst:(____ptrval____) refcnt:-1 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 4845 Comm: syz-executor493 Not tainted 4.18.0-rc3+ #10 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+0x1c9/0x2b4 lib/dump_stack.c:113 panic+0x238/0x4e7 kernel/panic.c:184 dst_release: dst:(____ptrval____) refcnt:-2 dst_release: dst:(____ptrval____) refcnt:-3 __warn.cold.8+0x163/0x1ba kernel/panic.c:536 dst_release: dst:(____ptrval____) refcnt:-4 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296 dst_release: dst:(____ptrval____) refcnt:-5 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 RIP: 0010:dst_hold include/net/dst.h:239 [inline] RIP: 0010:ip6_setup_cork+0xd66/0x1830 net/ipv6/ip6_output.c:1204 Code: c1 ed 03 89 9d 18 ff ff ff 48 b8 00 00 00 00 00 fc ff df 41 c6 44 05 00 f8 e9 2d 01 00 00 4c 8b a5 c8 fe ff ff e8 1a f6 e6 fa <0f> 0b e9 6a fc ff ff e8 0e f6 e6 fa 48 8b 85 d0 fe ff ff 48 8d 78 RSP: 0018:ffff8801a8fcf178 EFLAGS: 00010293 RAX: ffff8801a8eba5c0 RBX: 0000000000000000 RCX: ffffffff869511e6 RDX: 0000000000000000 RSI: ffffffff869515b6 RDI: 0000000000000005 RBP: ffff8801a8fcf2c8 R08: ffff8801a8eba5c0 R09: ffffed0035ac8338 R10: ffffed0035ac8338 R11: ffff8801ad6419c3 R12: ffff8801a8fcf720 R13: ffff8801a8fcf6a0 R14: ffff8801ad6419c0 R15: ffff8801ad641980 ip6_make_skb+0x2c8/0x600 net/ipv6/ip6_output.c:1768 udpv6_sendmsg+0x2c90/0x35f0 net/ipv6/udp.c:1376 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:641 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:651 ___sys_sendmsg+0x51d/0x930 net/socket.c:2125 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2220 __do_sys_sendmmsg net/socket.c:2249 [inline] __se_sys_sendmmsg net/socket.c:2246 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2246 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446ba9 Code: e8 cc bb 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb39a469da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000006dcc54 RCX: 0000000000446ba9 RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003 RBP: 00000000006dcc50 R08: 00007fb39a46a700 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 45c828efc7a64843 R13: e6eeb815b9d8a477 R14: 5068caf6f713c6fc R15: 0000000000000001 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes") Reported-by: syzbot+902e2a1bcd4f7808cef5@syzkaller.appspotmail.com Reported-by: syzbot+8ae62d67f647abeeceb9@syzkaller.appspotmail.com Reported-by: syzbot+3f08feb14086930677d0@syzkaller.appspotmail.com Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-22multicast: do not restore deleted record source filter mode to new oneHangbin Liu1-2/+1
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 <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-22net/ipv6: Fix linklocal to global address with VRFDavid Ahern2-4/+7
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 <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-19ipv6: sr: fix useless rol32 call on hashColin Ian King1-1/+1
The rol32 call is currently rotating hash but the rol'd value is being discarded. I believe the current code is incorrect and hash should be assigned the rotated value returned from rol32. Detected by CoverityScan, CID#1468411 ("Useless call") Fixes: b5facfdba14c ("ipv6: sr: Compute flowlabel for outer IPv6 header of seg6 encap mode") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: dlebrun@google.com Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-18ipv6: ila: select CONFIG_DST_CACHEArnd Bergmann1-0/+1
My randconfig builds came across an old missing dependency for ILA: ERROR: "dst_cache_set_ip6" [net/ipv6/ila/ila.ko] undefined! ERROR: "dst_cache_get" [net/ipv6/ila/ila.ko] undefined! ERROR: "dst_cache_init" [net/ipv6/ila/ila.ko] undefined! ERROR: "dst_cache_destroy" [net/ipv6/ila/ila.ko] undefined! We almost never run into this by accident because randconfig builds end up selecting DST_CACHE from some other tunnel protocol, and this one appears to be the only one missing the explicit 'select'. >From all I can tell, this problem first appeared in linux-4.9 when dst_cache support got added to ILA. Fixes: 79ff2fc31e0f ("ila: Cache a route to translated address") Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-17net/ipv6: Do not allow device only routes via the multipath APIDavid Ahern1-0/+7
Eric reported that reverting the patch that fixed and simplified IPv6 multipath routes means reverting back to invalid userspace notifications. eg., $ ip -6 route add 2001:db8:1::/64 nexthop dev eth0 nexthop dev eth1 only generates a single notification: 2001:db8:1::/64 dev eth0 metric 1024 pref medium While working on a fix for this problem I found another case that is just broken completely - a multipath route with a gateway followed by device followed by gateway: $ ip -6 ro add 2001:db8:103::/64 nexthop via 2001:db8:1::64 nexthop dev dummy2 nexthop via 2001:db8:3::64 In this case the device only route is dropped completely - no notification to userpsace but no addition to the FIB either: $ ip -6 ro ls 2001:db8:1::/64 dev dummy1 proto kernel metric 256 pref medium 2001:db8:2::/64 dev dummy2 proto kernel metric 256 pref medium 2001:db8:3::/64 dev dummy3 proto kernel metric 256 pref medium 2001:db8:103::/64 metric 1024 nexthop via 2001:db8:1::64 dev dummy1 weight 1 nexthop via 2001:db8:3::64 dev dummy3 weight 1 pref medium fe80::/64 dev dummy1 proto kernel metric 256 pref medium fe80::/64 dev dummy2 proto kernel metric 256 pref medium fe80::/64 dev dummy3 proto kernel metric 256 pref medium Really, IPv6 multipath is just FUBAR'ed beyond repair when it comes to device only routes, so do not allow it all. This change will break any scripts relying on the mpath api for insert, but I don't see any other way to handle the permutations. Besides, since the routes are added to the FIB as standalone (non-multipath) routes the kernel is not doing what the user requested, so it might as well tell the user that. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16ipv6: make DAD fail with enhanced DAD when nonce length differsSabrina Dubroca1-1/+1
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 <sd@queasysnail.net> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16net: ip6_gre: get ipv6hdr after skb_cow_head()Prashant Bhole1-1/+2
A KASAN:use-after-free bug was found related to ip6-erspan while running selftests/net/ip6_gre_headroom.sh It happens because of following sequence: - ipv6hdr pointer is obtained from skb - skb_cow_head() is called, skb->head memory is reallocated - old data is accessed using ipv6hdr pointer skb_cow_head() call was added in e41c7c68ea77 ("ip6erspan: make sure enough headroom at xmit."), but looking at the history there was a chance of similar bug because gre_handle_offloads() and pskb_trim() can also reallocate skb->head memory. Fixes tag points to commit which introduced possibility of this bug. This patch moves ipv6hdr pointer assignment after skb_cow_head() call. Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support") Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> Reviewed-by: Greg Rose <gvrose8192@gmail.com> Acked-by: William Tu <u9012063@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16ipv6/mcast: init as INCLUDE when join SSM INCLUDE groupHangbin Liu2-21/+48
This an IPv6 version patch of "ipv4/igmp: init group mode as INCLUDE when join source group". From RFC3810, part 6.1: If no per-interface state existed for that multicast address before the change (i.e., the change consisted of creating a new per-interface record), or if no state exists after the change (i.e., the change consisted of deleting a per-interface record), then the "non-existent" state is considered to have an INCLUDE filter mode and an empty source list. Which means a new multicast group should start with state IN(). Currently, for MLDv2 SSM JOIN_SOURCE_GROUP mode, we first call ipv6_sock_mc_join(), then ip6_mc_source(), which will trigger a TO_IN() message instead of ALLOW(). The issue was exposed by commit a052517a8ff65 ("net/multicast: should not send source list records when have filter mode change"). Before this change, we sent both ALLOW(A) and TO_IN(A). Now, we only send TO_IN(A). Fix it by adding a new parameter to init group mode. Also add some wrapper functions to avoid changing too much code. v1 -> v2: In the first version I only cleared the group change record. But this is not enough. Because when a new group join, it will init as EXCLUDE and trigger a filter mode change in ip/ip6_mc_add_src(), which will clear all source addresses sf_crcount. This will prevent early joined address sending state change records if multi source addressed joined at the same time. In v2 patch, I fixed it by directly initializing the mode to INCLUDE for SSM JOIN_SOURCE_GROUP. I also split the original patch into two separated patches for IPv4 and IPv6. There is also a difference between v4 and v6 version. For IPv6, when the interface goes down and up, we will send correct state change record with unspecified IPv6 address (::) with function ipv6_mc_up(). But after DAD is completed, we resend the change record TO_IN() in mld_send_initial_cr(). Fix it by sending ALLOW() for INCLUDE mode in mld_send_initial_cr(). Fixes: a052517a8ff65 ("net/multicast: should not send source list records when have filter mode change") Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nfDavid S. Miller3-6/+15
Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for your net tree: 1) Missing module autoloadfor icmp and icmpv6 x_tables matches, from Florian Westphal. 2) Possible non-linear access to TCP header from tproxy, from Mate Eckl. 3) Do not allow rbtree to be used for single elements, this patch moves all set backend into one single module since such thing can only happen if hashtable module is explicitly blacklisted, which should not ever be done. 4) Reject error and standard targets from nft_compat for sanity reasons, they are never used from there. 5) Don't crash on double hashsize module parameter, from Andrey Ryabinin. 6) Drop dst on skb before placing it in the fragmentation reassembly queue, from Florian Westphal. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-09netfilter: ipv6: nf_defrag: drop skb dst before queueingFlorian Westphal1-0/+2
Eric Dumazet reports: Here is a reproducer of an annoying bug detected by syzkaller on our production kernel [..] ./b78305423 enable_conntrack Then : sleep 60 dmesg | tail -10 [ 171.599093] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 181.631024] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 191.687076] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 201.703037] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 211.711072] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 221.959070] unregister_netdevice: waiting for lo to become free. Usage count = 2 Reproducer sends ipv6 fragment that hits nfct defrag via LOCAL_OUT hook. skb gets queued until frag timer expiry -- 1 minute. Normally nf_conntrack_reasm gets called during prerouting, so skb has no dst yet which might explain why this wasn't spotted earlier. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: John Sperbeck <jsperbeck@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Tested-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-06netfilter: nf_tproxy: fix possible non-linear access to transport headerMáté Eckl1-6/+12
This patch fixes a silent out-of-bound read possibility that was present because of the misuse of this function. Mostly it was called with a struct udphdr *hp which had only the udphdr part linearized by the skb_header_pointer, however nf_tproxy_get_sock_v{4,6} uses it as a tcphdr pointer, so some reads for tcp specific attributes may be invalid. Fixes: a583636a83ea ("inet: refactor inet[6]_lookup functions to take skb") Signed-off-by: Máté Eckl <ecklm94@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-05ipv6: make ipv6_renew_options() interrupt/kernel safePaul Moore3-95/+52
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: <IRQ> 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 </IRQ> ... 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 <viro@zeniv.linux.org.uk> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>