linux.git/net/ipv6, branch v4.19

net/ipv6: Fix index counter for unicast addresses in in6_dump_addrs

2018-10-20T22:43:14+00:00

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 
Signed-off-by: David S. Miller

ip6_tunnel: Fix encapsulation layout

2018-10-18T23:54:40+00:00

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 
Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2018-10-18T16:55:08+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2018-10-18

1) Free the xfrm interface gro_cells when deleting the
   interface, otherwise we leak it. From Li RongQing.

2) net/core/flow.c does not exist anymore, so remove it
   from the MAINTAINERS file.

3) Fix a slab-out-of-bounds in _decode_session6.
   From Alexei Starovoitov.

4) Fix RCU protection when policies inserted into
   thei bydst lists. From Florian Westphal.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller

udp6: fix encap return code for resubmitting

2018-10-18T05:26:53+00:00

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 
Signed-off-by: David S. Miller

ipv6: mcast: fix a use-after-free in inet6_mc_check

2018-10-16T05:38:55+00:00

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 
Reported-by: syzbot 
Signed-off-by: David S. Miller

ipv6: rate-limit probes for neighbourless routes

2018-10-16T05:18:27+00:00

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 
Reviewed-by: Stefano Brivio 
Signed-off-by: David S. Miller

net/xfrm: fix out-of-bounds packet access

2018-10-11T11:24:46+00:00

BUG: KASAN: slab-out-of-bounds in _decode_session6+0x1331/0x14e0
net/ipv6/xfrm6_policy.c:161
Read of size 1 at addr ffff8801d882eec7 by task syz-executor1/6667
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
  print_address_description+0x6c/0x20b mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
  __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
  _decode_session6+0x1331/0x14e0 net/ipv6/xfrm6_policy.c:161
  __xfrm_decode_session+0x71/0x140 net/xfrm/xfrm_policy.c:2299
  xfrm_decode_session include/net/xfrm.h:1232 [inline]
  vti6_tnl_xmit+0x3c3/0x1bc1 net/ipv6/ip6_vti.c:542
  __netdev_start_xmit include/linux/netdevice.h:4313 [inline]
  netdev_start_xmit include/linux/netdevice.h:4322 [inline]
  xmit_one net/core/dev.c:3217 [inline]
  dev_hard_start_xmit+0x272/0xc10 net/core/dev.c:3233
  __dev_queue_xmit+0x2ab2/0x3870 net/core/dev.c:3803
  dev_queue_xmit+0x17/0x20 net/core/dev.c:3836

Reported-by: syzbot+acffccec848dc13fe459@syzkaller.appspotmail.com
Reported-by: Eric Dumazet 
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Steffen Klassert

net/ipv6: stop leaking percpu memory in fib6 info

2018-10-11T05:42:54+00:00

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 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

ipv6: take rcu lock in rawv6_send_hdrinc()

2018-10-05T21:45:34+00:00

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 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2018-10-02T05:29:25+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2018-10-01

1) Validate address prefix lengths in the xfrm selector,
   otherwise we may hit undefined behaviour in the
   address matching functions if the prefix is too
   big for the given address family.

2) Fix skb leak on local message size errors.
   From Thadeu Lima de Souza Cascardo.

3) We currently reset the transport header back to the network
   header after a transport mode transformation is applied. This
   leads to an incorrect transport header when multiple transport
   mode transformations are applied. Reset the transport header
   only after all transformations are already applied to fix this.
   From Sowmini Varadhan.

4) We only support one offloaded xfrm, so reset crypto_done after
   the first transformation in xfrm_input(). Otherwise we may call
   the wrong input method for subsequent transformations.
   From Sowmini Varadhan.

5) Fix NULL pointer dereference when skb_dst_force clears the dst_entry.
   skb_dst_force does not really force a dst refcount anymore, it might
   clear it instead. xfrm code did not expect this, add a check to not
   dereference skb_dst() if it was cleared by skb_dst_force.

6) Validate xfrm template mode, otherwise we can get a stack-out-of-bounds
   read in xfrm_state_find. From Sean Tranchetti.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller