syzbot


INFO: task hung in rtnetlink_rcv_msg

Status: premoderation: reported on 2025/06/21 07:28
Reported-by: syzbot+30a9d1f77f95b0e4b07c@syzkaller.appspotmail.com
First crash: 3d23h, last: 7h13m
Similar bugs (13)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in rtnetlink_rcv_msg 1 711d 711d 0/3 auto-obsoleted due to no activity on 2023/10/22 21:13
linux-4.19 INFO: task hung in rtnetlink_rcv_msg (2) 14 1253d 1433d 0/1 auto-closed as invalid on 2022/05/18 11:30
linux-4.19 INFO: task hung in rtnetlink_rcv_msg (3) 8 866d 1100d 0/1 upstream: reported on 2022/06/20 23:55
linux-4.19 INFO: task hung in rtnetlink_rcv_msg 11 1685d 2007d 0/1 auto-closed as invalid on 2021/03/12 19:03
upstream INFO: task hung in rtnetlink_rcv_msg (2) net C inconclusive 548 92d 301d 0/29 closed as invalid on 2025/04/18 16:40
linux-6.1 INFO: task hung in rtnetlink_rcv_msg (3) origin:lts-only syz error 13 17d 278d 0/3 upstream: reported syz repro on 2024/09/19 14:16
linux-5.15 INFO: task hung in rtnetlink_rcv_msg (3) 1 69d 69d 0/3 upstream: reported on 2025/04/17 04:34
upstream INFO: task hung in rtnetlink_rcv_msg net C inconclusive inconclusive 1970 351d 2314d 26/29 fixed on 2024/07/09 19:14
linux-4.14 INFO: task hung in rtnetlink_rcv_msg 1 846d 846d 0/1 upstream: reported on 2023/03/01 21:15
linux-5.15 INFO: task hung in rtnetlink_rcv_msg (2) 70 221d 513d 0/3 auto-obsoleted due to no activity on 2025/01/24 13:11
linux-6.1 INFO: task hung in rtnetlink_rcv_msg (2) 67 350d 515d 0/3 auto-obsoleted due to no activity on 2024/09/17 07:45
linux-6.1 INFO: task hung in rtnetlink_rcv_msg 1 636d 636d 0/3 auto-obsoleted due to no activity on 2024/01/09 18:18
upstream INFO: task hung in cangw_pernet_exit (3) can syz unreliable 290 1275d 1381d 0/29 closed as invalid on 2022/02/08 10:22

Sample crash report:
INFO: task syz-executor:7588 blocked for more than 122 seconds.
      Not tainted 6.12.30-syzkaller-g94ce385c22d5 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:7588  tgid:7588  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x75f/0xa00 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x22e/0x4a0 net/netlink/af_netlink.c:2537
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1316 [inline]
 netlink_unicast+0x8c6/0xa60 net/netlink/af_netlink.c:1342
 netlink_sendmsg+0x7f0/0xaf0 net/netlink/af_netlink.c:1886
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x66d/0x6f0 net/socket.c:2217
 __do_sys_sendto net/socket.c:2229 [inline]
 __se_sys_sendto net/socket.c:2225 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2225
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f47e2990763
RSP: 002b:00007ffe05509838 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f47e36e4620 RCX: 00007f47e2990763
RDX: 0000000000000028 RSI: 00007f47e36e4670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffe05509854 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f47e36e4670 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.30-syzkaller-g94ce385c22d5 #0 16e511e29439c8b2668c1520ec6e7e54ef5e5f6a
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:229 [inline]
 watchdog+0xd8f/0xed0 kernel/hung_task.c:385
 kthread+0x2ca/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20 Comm: rcuop/0 Not tainted 6.12.30-syzkaller-g94ce385c22d5 #0 16e511e29439c8b2668c1520ec6e7e54ef5e5f6a
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:rt6_score_route+0x6d/0x8a0 net/ipv6/route.c:754
Code: 00 74 08 4c 89 ef e8 b2 0e fd fc 41 bc e0 00 00 00 4d 03 65 00 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 0f 85 77 06 00 00 45 8b 24 24 44 89 e7 89 de e8 7d 18 a7 fc
RSP: 0018:ffffc9000022fb98 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: 000000000000000d RCX: dffffc0000000000
RDX: ffff888103664c00 RSI: 000000000000000d RDI: 0000000000000000
RBP: ffffc9000022fc28 R08: ffffc9000022ff80 R09: ffffc9000022ff90
R10: ffffc900002300f0 R11: fffff52000046022 R12: ffff88810739a0e0
R13: ffff88810c7988c0 R14: 0000000000000003 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcb82df84c0 CR3: 0000000109fe6000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000800
DR3: 0000000100000001 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 find_match+0x176/0x10f0 net/ipv6/route.c:786
 __find_rr_leaf+0x23c/0x790 net/ipv6/route.c:869
 find_rr_leaf net/ipv6/route.c:890 [inline]
 rt6_select net/ipv6/route.c:934 [inline]
 fib6_table_lookup+0x2c5/0x9b0 net/ipv6/route.c:2230
 ip6_pol_route+0x167/0x12c0 net/ipv6/route.c:2266
 ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2323
 pol_lookup_func include/net/ip6_fib.h:626 [inline]
 fib6_rule_lookup+0x4cc/0x6b0 net/ipv6/fib6_rules.c:117
 ip6_route_input_lookup net/ipv6/route.c:2335 [inline]
 ip6_route_input+0x59f/0x8d0 net/ipv6/route.c:2631
 ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline]
 ip6_rcv_finish+0x15a/0x3c0 net/ipv6/ip6_input.c:77
 NF_HOOK include/linux/netfilter.h:317 [inline]
 ipv6_rcv+0xed/0x220 net/ipv6/ip6_input.c:309
 __netif_receive_skb_one_core net/core/dev.c:5757 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 netif_receive_skb_internal net/core/dev.c:5956 [inline]
 netif_receive_skb+0x147/0x7b0 net/core/dev.c:6015
 br_netif_receive_skb net/bridge/br_input.c:30 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_pass_frame_up+0x126/0x1c0 net/bridge/br_input.c:70
 br_handle_frame_finish+0x12d9/0x1720 net/bridge/br_input.c:221
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xf4b/0x3940 net/core/dev.c:5651
 __netif_receive_skb_one_core net/core/dev.c:5755 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 process_backlog+0x3e5/0xae0 net/core/dev.c:6202
 __napi_poll+0xd0/0x610 net/core/dev.c:6853
 napi_poll net/core/dev.c:6922 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7044
 handle_softirqs+0x1ae/0x630 kernel/softirq.c:603
 __do_softirq+0xf/0x16 kernel/softirq.c:641
 do_softirq+0xa6/0x100 kernel/softirq.c:485
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:412
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2586
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957
 kthread+0x2ca/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 101531 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:5e:10:54:ff:42:75, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:5e:10:54:ff:42:75, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/25 00:04 android16-6.12 94ce385c22d5 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/23 08:46 android16-6.12 5bf4b91e3333 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/23 06:43 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/23 03:03 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/22 23:26 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/22 16:02 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/22 09:17 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/21 21:24 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
2025/06/21 07:28 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnetlink_rcv_msg
* Struck through repros no longer work on HEAD.