syzbot


INFO: task hung in rtnetlink_rcv_msg (3)

Status: upstream: reported syz repro on 2024/09/19 14:16
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+36e12ffa6b139eaf655c@syzkaller.appspotmail.com
First crash: 262d, last: 1d18h
Bug presence (2)
Date Name Commit Repro Result
2025/01/05 linux-6.1.y (ToT) 7dc732d24ff7 C [report] INFO: task hung in __netlink_dump_start
2025/01/05 upstream (ToT) ab75170520d4 C Didn't crash
Similar bugs (12)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in rtnetlink_rcv_msg 1 695d 695d 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 1237d 1417d 0/1 auto-closed as invalid on 2022/05/18 11:30
linux-4.19 INFO: task hung in rtnetlink_rcv_msg (3) 8 850d 1084d 0/1 upstream: reported on 2022/06/20 23:55
linux-4.19 INFO: task hung in rtnetlink_rcv_msg 11 1669d 1991d 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 76d 285d 0/28 closed as invalid on 2025/04/18 16:40
linux-5.15 INFO: task hung in rtnetlink_rcv_msg (3) 1 53d 53d 0/3 upstream: reported on 2025/04/17 04:34
upstream INFO: task hung in rtnetlink_rcv_msg net C inconclusive inconclusive 1970 335d 2298d 26/28 fixed on 2024/07/09 19:14
linux-4.14 INFO: task hung in rtnetlink_rcv_msg 1 830d 830d 0/1 upstream: reported on 2023/03/01 21:15
linux-5.15 INFO: task hung in rtnetlink_rcv_msg (2) 70 205d 497d 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 335d 499d 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 620d 620d 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 1259d 1365d 0/28 closed as invalid on 2022/02/08 10:22
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2025/05/28 20:09 18m fix candidate upstream error job log
2025/02/22 09:31 23m fix candidate upstream error job log

Sample crash report:
INFO: task syz-executor:4831 blocked for more than 146 seconds.
      Not tainted 6.1.138-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:4831  ppid:1      flags:0x00000001
Call trace:
 __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xdd4/0x1b2c kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6696
 __mutex_lock_common+0xad4/0x1f38 kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 rtnl_lock net/core/rtnetlink.c:74 [inline]
 rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x208/0x3c4 net/netlink/af_netlink.c:2493
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6171
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x600/0x818 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x6e8/0x9b0 net/netlink/af_netlink.c:1859
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x304/0x3fc net/socket.c:2153
 __do_sys_sendto net/socket.c:2165 [inline]
 __se_sys_sendto net/socket.c:2161 [inline]
 __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2161
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Showing all locks held in the system:
4 locks held by kworker/u4:0/9:
 #0: ffff0000c03dd138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x6b4/0x13a8 kernel/workqueue.c:2265
 #1: ffff80001c817c20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x6f8/0x13a8 kernel/workqueue.c:2267
 #2: ffff8000176cc890 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x12c/0xa74 net/core/net_namespace.c:594
 #3: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015247630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015247e50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffff800015246cc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
2 locks held by kworker/u4:2/39:
1 lock held by udevd/3915:
2 locks held by getty/4072:
 #0: ffff0000cfc04098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001ce602f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2ec/0xf9c drivers/tty/n_tty.c:2198
3 locks held by kworker/0:4/4378:
 #0: ffff0000d5f5b138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x6b4/0x13a8 kernel/workqueue.c:2265
 #1: ffff800020767c20 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6f8/0x13a8 kernel/workqueue.c:2267
 #2: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
3 locks held by kworker/1:4/4384:
 #0: ffff0000d5f5b138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x6b4/0x13a8 kernel/workqueue.c:2265
 #1: ffff8000208b7c20 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6f8/0x13a8 kernel/workqueue.c:2267
 #2: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
3 locks held by kworker/1:10/4390:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x6b4/0x13a8 kernel/workqueue.c:2265
 #1: ffff800020ba7c20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x6f8/0x13a8 kernel/workqueue.c:2267
 #2: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
3 locks held by kworker/0:6/4494:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x6b4/0x13a8 kernel/workqueue.c:2265
 #1: ffff00019f717b88 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x380/0x608 kernel/sched/psi.c:999
 #2: ffff0000c8365cf0 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x60/0xc74 kernel/sched/core.c:4111
3 locks held by kworker/u4:16/4751:
3 locks held by kworker/u4:17/4798:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x6b4/0x13a8 kernel/workqueue.c:2265
 #1: ffff800022647c20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x6f8/0x13a8 kernel/workqueue.c:2267
 #2: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
1 lock held by syz-executor/4831:
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:6150
3 locks held by kworker/u4:20/4941:
 #0: ffff0000c002a138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x6b4/0x13a8 kernel/workqueue.c:2265
 #1: ffff800023717c20 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x6f8/0x13a8 kernel/workqueue.c:2267
 #2: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
2 locks held by syz-executor/5058:
 #0: ffff8000176cc890 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x298/0x588 net/core/net_namespace.c:504
 #1: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
1 lock held by syz-executor/5182:
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:6150
1 lock held by syz-executor/5387:
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:6150
1 lock held by syz-executor/5512:
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:6150
1 lock held by syz-executor/5732:
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:6150
1 lock held by syz-executor/5855:
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffff8000176d8f08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6ec/0xce4 net/core/rtnetlink.c:6150
1 lock held by syz.0.271/5881:
 #0: ffff80001524c978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #0: ffff80001524c978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a8/0x6f0 kernel/rcu/tree_exp.h:962
3 locks held by syz.1.291/5978:

=============================================


Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/11 06:29 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2025/04/08 06:00 linux-6.1.y 3dfebb87d7eb a2ada0e7 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2025/01/05 15:26 linux-6.1.y 7dc732d24ff7 f3558dbf .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2025/05/06 07:01 linux-6.1.y ac7079a42ea5 ae98e6b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in rtnetlink_rcv_msg
2025/02/21 07:13 linux-6.1.y 0cbb5f65e52f 0808a665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in rtnetlink_rcv_msg
2025/01/22 20:56 linux-6.1.y f4f677285b38 a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in rtnetlink_rcv_msg
2024/11/29 20:34 linux-6.1.y e4d90d63d385 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in rtnetlink_rcv_msg
2025/06/07 13:29 linux-6.1.y 58485ff1a74f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2025/05/25 11:22 linux-6.1.y da3c5173c55f ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2024/12/27 21:48 linux-6.1.y 563edd786f0a d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2024/12/02 04:24 linux-6.1.y e4d90d63d385 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2024/11/09 21:17 linux-6.1.y d7039b844a1c 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
2024/09/19 14:15 linux-6.1.y e526b12bf916 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in rtnetlink_rcv_msg
* Struck through repros no longer work on HEAD.