linux-stable.git/net/ipv6/route.c, branch linux-5.4.y

net: ipv6: Discard next-hop MTU less than minimum link MTU

2025-07-17T16:25:06+00:00

commit 4a65dff81a04f874fa6915c7f069b4dc2c4010e4 upstream.

When a ICMPV6_PKT_TOOBIG report a next-hop MTU that is less than the IPv6
minimum link MTU, the estimated path MTU is reduced to the minimum link
MTU. This behaviour breaks TAHI IPv6 Core Conformance Test v6LC4.1.6:
Packet Too Big Less than IPv6 MTU.

Referring to RFC 8201 section 4: "If a node receives a Packet Too Big
message reporting a next-hop MTU that is less than the IPv6 minimum link
MTU, it must discard it. A node must not reduce its estimate of the Path
MTU below the IPv6 minimum link MTU on receipt of a Packet Too Big
message."

Drop the path MTU update if reported MTU is less than the minimum link MTU.

Signed-off-by: Georg Kohmann 
Signed-off-by: Jakub Kicinski 
Signed-off-by: WangYuli 
Signed-off-by: Greg Kroah-Hartman

ipv6: Set errno after ip_fib_metrics_init() in ip6_route_info_create().

2025-04-10T12:29:38+00:00

[ Upstream commit 9a81fc3480bf5dbe2bf80e278c440770f6ba2692 ]

While creating a new IPv6, we could get a weird -ENOMEM when
RTA_NH_ID is set and either of the conditions below is true:

  1) CONFIG_IPV6_SUBTREES is enabled and rtm_src_len is specified
  2) nexthop_get() fails

e.g.)

  # strace ip -6 route add fe80::dead:beef:dead:beef nhid 1 from ::
  recvmsg(3, {msg_iov=[{iov_base=[...[
    {error=-ENOMEM, msg=[... [...]]},
    [{nla_len=49, nla_type=NLMSGERR_ATTR_MSG}, "Nexthops can not be used with so"...]
  ]], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 148

Let's set err explicitly after ip_fib_metrics_init() in
ip6_route_info_create().

Fixes: f88d8ea67fbd ("ipv6: Plumb support for nexthop object in a fib6_info")
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: David Ahern 
Link: https://patch.msgid.link/20250312013854.61125-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

ipv6: Fix memleak of nhc_pcpu_rth_output in fib_check_nh_v6_gw().

2025-04-10T12:29:38+00:00

[ Upstream commit 9740890ee20e01f99ff1dde84c63dcf089fabb98 ]

fib_check_nh_v6_gw() expects that fib6_nh_init() cleans up everything
when it fails.

Commit 7dd73168e273 ("ipv6: Always allocate pcpu memory in a fib6_nh")
moved fib_nh_common_init() before alloc_percpu_gfp() within fib6_nh_init()
but forgot to add cleanup for fib6_nh->nh_common.nhc_pcpu_rth_output in
case it fails to allocate fib6_nh->rt6i_pcpu, resulting in memleak.

Let's call fib_nh_common_release() and clear nhc_pcpu_rth_output in the
error path.

Note that we can remove the fib6_nh_release() call in nh_create_ipv6()
later in net-next.git.

Fixes: 7dd73168e273 ("ipv6: Always allocate pcpu memory in a fib6_nh")
Signed-off-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250312010333.56001-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

ipv6: use RCU protection in ip6_default_advmss()

2025-03-13T11:43:17+00:00

[ Upstream commit 3c8ffcd248da34fc41e52a46e51505900115fc2a ]

ip6_default_advmss() needs rcu protection to make
sure the net structure it reads does not disappear.

Fixes: 5578689a4e3c ("[NETNS][IPV6] route6 - make route6 per namespace")
Signed-off-by: Eric Dumazet 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250205155120.1676781-11-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv6: avoid possible NULL deref in rt6_uncached_list_flush_dev()

2025-02-01T17:18:51+00:00

commit 04ccecfa959d3b9ae7348780d8e379c6486176ac upstream.

Blamed commit accidentally removed a check for rt->rt6i_idev being NULL,
as spotted by syzbot:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 10998 Comm: syz-executor Not tainted 6.11.0-rc6-syzkaller-00208-g625403177711 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
 RIP: 0010:rt6_uncached_list_flush_dev net/ipv6/route.c:177 [inline]
 RIP: 0010:rt6_disable_ip+0x33e/0x7e0 net/ipv6/route.c:4914
Code: 41 80 3c 04 00 74 0a e8 90 d0 9b f7 48 8b 7c 24 08 48 8b 07 48 89 44 24 10 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 64 d0 9b f7 48 8b 44 24 18 49 39 06
RSP: 0018:ffffc900047374e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff1100fdf8f33 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807efc78c0
RBP: ffffc900047375d0 R08: 0000000000000003 R09: fffff520008e6e8c
R10: dffffc0000000000 R11: fffff520008e6e8c R12: 1ffff1100fdf8f18
R13: ffff88807efc7998 R14: 0000000000000000 R15: ffff88807efc7930
FS:  0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020002a80 CR3: 0000000022f62000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
  addrconf_ifdown+0x15d/0x1bd0 net/ipv6/addrconf.c:3856
 addrconf_notify+0x3cb/0x1020
  notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
  call_netdevice_notifiers_extack net/core/dev.c:2032 [inline]
  call_netdevice_notifiers net/core/dev.c:2046 [inline]
  unregister_netdevice_many_notify+0xd81/0x1c40 net/core/dev.c:11352
  unregister_netdevice_many net/core/dev.c:11414 [inline]
  unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11289
  unregister_netdevice include/linux/netdevice.h:3129 [inline]
  __tun_detach+0x6b9/0x1600 drivers/net/tun.c:685
  tun_detach drivers/net/tun.c:701 [inline]
  tun_chr_close+0x108/0x1b0 drivers/net/tun.c:3510
  __fput+0x24a/0x8a0 fs/file_table.c:422
  task_work_run+0x24f/0x310 kernel/task_work.c:228
  exit_task_work include/linux/task_work.h:40 [inline]
  do_exit+0xa2f/0x27f0 kernel/exit.c:882
  do_group_exit+0x207/0x2c0 kernel/exit.c:1031
  __do_sys_exit_group kernel/exit.c:1042 [inline]
  __se_sys_exit_group kernel/exit.c:1040 [inline]
  __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040
  x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1acc77def9
Code: Unable to access opcode bytes at 0x7f1acc77decf.
RSP: 002b:00007ffeb26fa738 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1acc77def9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f1acc7dd508 R08: 00007ffeb26f84d7 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000003 R14: 00000000ffffffff R15: 00007ffeb26fa8e0
 
Modules linked in:
---[ end trace 0000000000000000 ]---
 RIP: 0010:rt6_uncached_list_flush_dev net/ipv6/route.c:177 [inline]
 RIP: 0010:rt6_disable_ip+0x33e/0x7e0 net/ipv6/route.c:4914
Code: 41 80 3c 04 00 74 0a e8 90 d0 9b f7 48 8b 7c 24 08 48 8b 07 48 89 44 24 10 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 64 d0 9b f7 48 8b 44 24 18 49 39 06
RSP: 0018:ffffc900047374e0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff1100fdf8f33 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807efc78c0
RBP: ffffc900047375d0 R08: 0000000000000003 R09: fffff520008e6e8c
R10: dffffc0000000000 R11: fffff520008e6e8c R12: 1ffff1100fdf8f18
R13: ffff88807efc7998 R14: 0000000000000000 R15: ffff88807efc7930
FS:  0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020002a80 CR3: 0000000022f62000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fixes: e332bc67cf5e ("ipv6: Don't call with rt6_uncached_list_flush_dev")
Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Reviewed-by: David Ahern 
Acked-by: Martin KaFai Lau 
Link: https://patch.msgid.link/20240913083147.3095442-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: BRUNO VERNAY 
Signed-off-by: Hugo SIMELIERE 
Signed-off-by: Greg Kroah-Hartman

net/ipv6: release expired exception dst cached in socket

2024-12-14T18:44:45+00:00

[ Upstream commit 3301ab7d5aeb0fe270f73a3d4810c9d1b6a9f045 ]

Dst objects get leaked in ip6_negative_advice() when this function is
executed for an expired IPv6 route located in the exception table. There
are several conditions that must be fulfilled for the leak to occur:
* an ICMPv6 packet indicating a change of the MTU for the path is received,
  resulting in an exception dst being created
* a TCP connection that uses the exception dst for routing packets must
  start timing out so that TCP begins retransmissions
* after the exception dst expires, the FIB6 garbage collector must not run
  before TCP executes ip6_negative_advice() for the expired exception dst

When TCP executes ip6_negative_advice() for an exception dst that has
expired and if no other socket holds a reference to the exception dst, the
refcount of the exception dst is 2, which corresponds to the increment
made by dst_init() and the increment made by the TCP socket for which the
connection is timing out. The refcount made by the socket is never
released. The refcount of the dst is decremented in sk_dst_reset() but
that decrement is counteracted by a dst_hold() intentionally placed just
before the sk_dst_reset() in ip6_negative_advice(). After
ip6_negative_advice() has finished, there is no other object tied to the
dst. The socket lost its reference stored in sk_dst_cache and the dst is
no longer in the exception table. The exception dst becomes a leaked
object.

As a result of this dst leak, an unbalanced refcount is reported for the
loopback device of a net namespace being destroyed under kernels that do
not contain e5f80fcf869a ("ipv6: give an IPv6 dev to blackhole_netdev"):
unregister_netdevice: waiting for lo to become free. Usage count = 2

Fix the dst leak by removing the dst_hold() in ip6_negative_advice(). The
patch that introduced the dst_hold() in ip6_negative_advice() was
92f1655aa2b22 ("net: fix __dst_negative_advice() race"). But 92f1655aa2b22
merely refactored the code with regards to the dst refcount so the issue
was present even before 92f1655aa2b22. The bug was introduced in
54c1a859efd9f ("ipv6: Don't drop cache route entry unless timer actually
expired.") where the expired cached route is deleted and the sk_dst_cache
member of the socket is set to NULL by calling dst_negative_advice() but
the refcount belonging to the socket is left unbalanced.

The IPv4 version - ipv4_negative_advice() - is not affected by this bug.
When the TCP connection times out ipv4_negative_advice() merely resets the
sk_dst_cache of the socket while decrementing the refcount of the
exception dst.

Fixes: 92f1655aa2b22 ("net: fix __dst_negative_advice() race")
Fixes: 54c1a859efd9f ("ipv6: Don't drop cache route entry unless timer actually expired.")
Link: https://lore.kernel.org/netdev/20241113105611.GA6723@incl/T/#u
Signed-off-by: Jiri Wiesner 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/20241128085950.GA4505@incl
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv6: prevent possible NULL dereference in rt6_probe()

2024-07-05T07:08:22+00:00

[ Upstream commit b86762dbe19a62e785c189f313cda5b989931f37 ]

syzbot caught a NULL dereference in rt6_probe() [1]

Bail out if  __in6_dev_get() returns NULL.

[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cb: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000658-0x000000000000065f]
CPU: 1 PID: 22444 Comm: syz-executor.0 Not tainted 6.10.0-rc2-syzkaller-00383-gb8481381d4e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
 RIP: 0010:rt6_probe net/ipv6/route.c:656 [inline]
 RIP: 0010:find_match+0x8c4/0xf50 net/ipv6/route.c:758
Code: 14 fd f7 48 8b 85 38 ff ff ff 48 c7 45 b0 00 00 00 00 48 8d b8 5c 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 19
RSP: 0018:ffffc900034af070 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90004521000
RDX: 00000000000000cb RSI: ffffffff8990d0cd RDI: 000000000000065c
RBP: ffffc900034af150 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000002 R12: 000000000000000a
R13: 1ffff92000695e18 R14: ffff8880244a1d20 R15: 0000000000000000
FS:  00007f4844a5a6c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31b27000 CR3: 000000002d42c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
  rt6_nh_find_match+0xfa/0x1a0 net/ipv6/route.c:784
  nexthop_for_each_fib6_nh+0x26d/0x4a0 net/ipv4/nexthop.c:1496
  __find_rr_leaf+0x6e7/0xe00 net/ipv6/route.c:825
  find_rr_leaf net/ipv6/route.c:853 [inline]
  rt6_select net/ipv6/route.c:897 [inline]
  fib6_table_lookup+0x57e/0xa30 net/ipv6/route.c:2195
  ip6_pol_route+0x1cd/0x1150 net/ipv6/route.c:2231
  pol_lookup_func include/net/ip6_fib.h:616 [inline]
  fib6_rule_lookup+0x386/0x720 net/ipv6/fib6_rules.c:121
  ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline]
  ip6_route_output_flags+0x1d0/0x640 net/ipv6/route.c:2651
  ip6_dst_lookup_tail.constprop.0+0x961/0x1760 net/ipv6/ip6_output.c:1147
  ip6_dst_lookup_flow+0x99/0x1d0 net/ipv6/ip6_output.c:1250
  rawv6_sendmsg+0xdab/0x4340 net/ipv6/raw.c:898
  inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg net/socket.c:745 [inline]
  sock_write_iter+0x4b8/0x5c0 net/socket.c:1160
  new_sync_write fs/read_write.c:497 [inline]
  vfs_write+0x6b6/0x1140 fs/read_write.c:590
  ksys_write+0x1f8/0x260 fs/read_write.c:643
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: 52e1635631b3 ("[IPV6]: ROUTE: Add router_probe_interval sysctl.")
Signed-off-by: Eric Dumazet 
Reviewed-by: Jason Xing 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20240615151454.166404-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv6: prevent possible NULL deref in fib6_nh_init()

2024-07-05T07:08:22+00:00

[ Upstream commit 2eab4543a2204092c3a7af81d7d6c506e59a03a6 ]

syzbot reminds us that in6_dev_get() can return NULL.

fib6_nh_init()
    ip6_validate_gw(  &idev  )
        ip6_route_check_nh(  idev  )
            *idev = in6_dev_get(dev); // can be NULL

Oops: general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]
CPU: 0 PID: 11237 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
 RIP: 0010:fib6_nh_init+0x640/0x2160 net/ipv6/route.c:3606
Code: 00 00 fc ff df 4c 8b 64 24 58 48 8b 44 24 28 4c 8b 74 24 30 48 89 c1 48 89 44 24 28 48 8d 98 e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 b3 17 00 00 8b 1b 31 ff 89 de e8 b8 8b
RSP: 0018:ffffc900032775a0 EFLAGS: 00010202
RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffffc90003277a54 RDI: ffff88802b3a08d8
RBP: ffffc900032778b0 R08: 00000000000002fc R09: 0000000000000000
R10: 00000000000002fc R11: 0000000000000000 R12: ffff88802b3a08b8
R13: 1ffff9200064eec8 R14: ffffc90003277a00 R15: dffffc0000000000
FS:  00007f940feb06c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000245e8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
  ip6_route_info_create+0x99e/0x12b0 net/ipv6/route.c:3809
  ip6_route_add+0x28/0x160 net/ipv6/route.c:3853
  ipv6_route_ioctl+0x588/0x870 net/ipv6/route.c:4483
  inet6_ioctl+0x21a/0x280 net/ipv6/af_inet6.c:579
  sock_do_ioctl+0x158/0x460 net/socket.c:1222
  sock_ioctl+0x629/0x8e0 net/socket.c:1341
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:907 [inline]
  __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f940f07cea9

Fixes: 428604fb118f ("ipv6: do not set routes if disable_ipv6 has been enabled")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Acked-by: Lorenzo Bianconi 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20240614082002.26407-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net/ipv6: Fix the RT cache flush via sysctl using a previous delay

2024-07-05T07:08:17+00:00

[ Upstream commit 14a20e5b4ad998793c5f43b0330d9e1388446cf3 ]

The net.ipv6.route.flush system parameter takes a value which specifies
a delay used during the flush operation for aging exception routes. The
written value is however not used in the currently requested flush and
instead utilized only in the next one.

A problem is that ipv6_sysctl_rtcache_flush() first reads the old value
of net->ipv6.sysctl.flush_delay into a local delay variable and then
calls proc_dointvec() which actually updates the sysctl based on the
provided input.

Fix the problem by switching the order of the two operations.

Fixes: 4990509f19e8 ("[NETNS][IPV6]: Make sysctls route per namespace.")
Signed-off-by: Petr Pavlu 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20240607112828.30285-1-petr.pavlu@suse.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv6: fix possible race in __fib6_drop_pcpu_from()

2024-07-05T07:08:13+00:00

[ Upstream commit b01e1c030770ff3b4fe37fc7cc6bca03f594133f ]

syzbot found a race in __fib6_drop_pcpu_from() [1]

If compiler reads more than once (*ppcpu_rt),
second read could read NULL, if another cpu clears
the value in rt6_get_pcpu_route().

Add a READ_ONCE() to prevent this race.

Also add rcu_read_lock()/rcu_read_unlock() because
we rely on RCU protection while dereferencing pcpu_rt.

[1]

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
CPU: 0 PID: 7543 Comm: kworker/u8:17 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: netns cleanup_net
 RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10a/0x370 net/ipv6/ip6_fib.c:984
Code: f8 48 c1 e8 03 80 3c 28 00 0f 85 16 02 00 00 4d 8b 3f 4d 85 ff 74 31 e8 74 a7 fa f7 49 8d bf 90 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 1e 02 00 00 49 8b 87 90 00 00 00 48 8b 0c 24 48
RSP: 0018:ffffc900040df070 EFLAGS: 00010206
RAX: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16
RDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000001 R11: 0000000000000006 R12: ffff88807fa080b8
R13: fffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c26000 CR3: 000000005d56e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
  __fib6_drop_pcpu_from net/ipv6/ip6_fib.c:966 [inline]
  fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [inline]
  fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038
  fib6_del_route net/ipv6/ip6_fib.c:1998 [inline]
  fib6_del+0xa70/0x17b0 net/ipv6/ip6_fib.c:2043
  fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205
  fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127
  fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2175
  fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255
  __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271
  rt6_sync_down_dev net/ipv6/route.c:4906 [inline]
  rt6_disable_ip+0x7ed/0xa00 net/ipv6/route.c:4911
  addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855
  addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778
  notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
  call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992
  call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
  call_netdevice_notifiers net/core/dev.c:2044 [inline]
  dev_close_many+0x333/0x6a0 net/core/dev.c:1585
  unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193
  unregister_netdevice_many net/core/dev.c:11276 [inline]
  default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759
  ops_exit_list+0x128/0x180 net/core/net_namespace.c:178
  cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640
  process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
  process_scheduled_works kernel/workqueue.c:3312 [inline]
  worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
  kthread+0x2c1/0x3a0 kernel/kthread.c:389
  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Fixes: d52d3997f843 ("ipv6: Create percpu rt6_info")
Signed-off-by: Eric Dumazet 
Cc: Martin KaFai Lau 
Link: https://lore.kernel.org/r/20240604193549.981839-1-edumazet@google.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin