syzbot


INFO: task hung in rtnetlink_rcv_msg (2)

Status: upstream: reported on 2024/01/27 00:38
Reported-by: syzbot+91c7f64c0367c9478b49@syzkaller.appspotmail.com
First crash: 96d, last: 53d
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in rtnetlink_rcv_msg 1 292d 292d 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 835d 1014d 0/1 auto-closed as invalid on 2022/05/18 11:30
linux-4.19 INFO: task hung in rtnetlink_rcv_msg (3) 8 448d 681d 0/1 upstream: reported on 2022/06/20 23:55
linux-4.19 INFO: task hung in rtnetlink_rcv_msg 11 1267d 1588d 0/1 auto-closed as invalid on 2021/03/12 19:03
upstream INFO: task hung in rtnetlink_rcv_msg net C inconclusive inconclusive 914 4d09h 1896d 0/26 upstream: reported C repro on 2019/02/22 17:00
linux-4.14 INFO: task hung in rtnetlink_rcv_msg 1 427d 427d 0/1 upstream: reported on 2023/03/01 21:15
linux-5.15 INFO: task hung in rtnetlink_rcv_msg (2) 3 53d 94d 0/3 upstream: reported on 2024/01/29 02:32
linux-6.1 INFO: task hung in rtnetlink_rcv_msg 1 217d 217d 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 856d 963d 0/26 closed as invalid on 2022/02/08 10:22

Sample crash report:
INFO: task dhcpcd:3215 blocked for more than 143 seconds.
      Not tainted 6.1.81-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:20744 pid:3215  ppid:3214   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:74 [inline]
 rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2508
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2597
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f83819efa4b
RSP: 002b:00007ffebd88aef8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f83819176c0 RCX: 00007f83819efa4b
RDX: 0000000000000000 RSI: 00007ffebd89f0a8 RDI: 0000000000000015
RBP: 0000000000000015 R08: 0000000000000000 R09: 00007ffebd89f0a8
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 00007ffebd89f0a8 R14: 0000000000000030 R15: 0000000000000001
 </TASK>
INFO: task kworker/1:5:3779 blocked for more than 144 seconds.
      Not tainted 6.1.81-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:5     state:D stack:25024 pid:3779  ppid:2      flags:0x00004000
Workqueue: events linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 linkwatch_event+0xa/0x50 net/core/link_watch.c:263
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307
 </TASK>
INFO: task kworker/0:3:4004 blocked for more than 144 seconds.
      Not tainted 6.1.81-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D stack:26368 pid:4004  ppid:2      flags:0x00004000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307
 </TASK>
INFO: task syz-executor.3:5113 blocked for more than 145 seconds.
      Not tainted 6.1.81-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:21736 pid:5113  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:74 [inline]
 rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2508
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x480/0x600 net/socket.c:2148
 __do_sys_sendto net/socket.c:2160 [inline]
 __se_sys_sendto net/socket.c:2156 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2156
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb62247fa9c
RSP: 002b:00007ffdc0d2e1f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fb6230d4620 RCX: 00007fb62247fa9c
RDX: 0000000000000068 RSI: 00007fb6230d4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffdc0d2e244 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fb6230d4670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor.4:5115 blocked for more than 146 seconds.
      Not tainted 6.1.81-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:21736 pid:5115  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:74 [inline]
 rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2508
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x480/0x600 net/socket.c:2148
 __do_sys_sendto net/socket.c:2160 [inline]
 __se_sys_sendto net/socket.c:2156 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2156
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa89347fa9c
RSP: 002b:00007ffc0fd217c0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fa8940d4620 RCX: 00007fa89347fa9c
RDX: 0000000000000028 RSI: 00007fa8940d4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffc0fd21814 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fa8940d4670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor.0:5121 blocked for more than 146 seconds.
      Not tainted 6.1.81-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:21736 pid:5121  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:74 [inline]
 rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2508
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x480/0x600 net/socket.c:2148
 __do_sys_sendto net/socket.c:2160 [inline]
 __se_sys_sendto net/socket.c:2156 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2156
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f61ede7fa9c
RSP: 002b:00007ffd0c56d230 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f61eead4620 RCX: 00007f61ede7fa9c
RDX: 0000000000000028 RSI: 00007f61eead4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd0c56d284 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f61eead4670 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u4:1/11:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12aa10 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12b210 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
2 locks held by kworker/1:1/26:
 #0: ffff888012472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000a1fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
1 lock held by khungtaskd/28:
 #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:319 [inline]
 #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:760 [inline]
 #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by kworker/u4:2/33:
1 lock held by dhcpcd/3215:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
2 locks held by getty/3299:
 #0: ffff888022202098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
2 locks held by kworker/u4:6/4337:
5 locks held by kworker/u4:7/15025:
 #0: ffff888012616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900061dfd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e28cad0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:563
 #3: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0x9d0 net/core/dev.c:11377
 #4: ffffffff8d12fe38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #4: ffffffff8d12fe38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3b0/0x8a0 kernel/rcu/tree_exp.h:949
3 locks held by kworker/0:0/2777:
 #0: ffff888027dbbd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc9000ba3fd20 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4654
3 locks held by kworker/1:2/2929:
 #0: ffff888027dbbd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900036ffd20 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4654
3 locks held by kworker/1:5/3779:
 #0: ffff888012470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90005b3fd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
3 locks held by kworker/0:3/4004:
 #0: ffff888012470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc900066efd20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
1 lock held by syz-executor.3/5113:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.4/5115:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.0/5121:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.3/5594:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.4/5599:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.0/5607:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.3/6029:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.4/6030:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.0/6039:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.2/6320:
1 lock held by syz-executor.2/6326:
1 lock held by syz-executor.2/6342:
1 lock held by syz-executor.1/6346:
2 locks held by syz-executor.2/6350:
3 locks held by syz-executor.2/6356:
2 locks held by syz-executor.1/6357:
2 locks held by syz-executor.1/6365:
2 locks held by syz-executor.2/6367:
3 locks held by syz-executor.2/6374:
 #0: ffff88814c8aa460 (sb_writers#4){.+.+}-{0:0}, at: do_coredump+0x1892/0x2700 fs/coredump.c:754
 #1: ffff888051efd440 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff888051efd440 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x3a0 fs/ext4/file.c:279
 #2: ffff88814c8aa0e0 (&type->s_umount_key#31){++++}-{3:3}, at: try_to_writeback_inodes_sb+0x1d/0xb0 fs/fs-writeback.c:2698
1 lock held by syz-executor.1/6376:
2 locks held by syz-executor.1/6381:
3 locks held by syz-executor.2/6384:
2 locks held by syz-executor.2/6390:
3 locks held by syz-executor.1/6392:
3 locks held by syz-executor.1/6398:
3 locks held by syz-executor.2/6400:
1 lock held by syz-executor.1/6407:
2 locks held by syz-executor.2/6408:
2 locks held by syz-executor.2/6414:
2 locks held by syz-executor.1/6416:
1 lock held by syz-executor.2/6421:
2 locks held by syz-executor.1/6426:
2 locks held by syz-executor.2/6432:
2 locks held by syz-executor.1/6434:
2 locks held by syz-executor.2/6442:
2 locks held by syz-executor.1/6443:
3 locks held by syz-executor.2/6450:
2 locks held by syz-executor.1/6452:
3 locks held by syz-executor.2/6457:
3 locks held by syz-executor.1/6460:
1 lock held by syz-executor.3/6469:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.4/6473:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
1 lock held by syz-executor.0/6474:
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e298d28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118
3 locks held by syz-executor.1/6479:
2 locks held by syz-executor.1/6484:
2 locks held by syz-executor.2/6487:
3 locks held by syz-executor.2/6493:
3 locks held by syz-executor.1/6495:
3 locks held by syz-executor.1/6502:
2 locks held by syz-executor.2/6503:
1 lock held by syz-executor.1/6506:
1 lock held by syz-executor.2/6512:
3 locks held by syz-executor.1/6511:
2 locks held by syz-executor.2/6513:

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.81-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 33 Comm: kworker/u4:2 Not tainted 6.1.81-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__local_bh_disable_ip+0x31/0x210 kernel/softirq.c:318
Code: 56 41 55 41 54 53 48 83 e4 e0 48 81 ec a0 00 00 00 41 89 f7 48 89 7c 24 18 65 48 8b 04 25 28 00 00 00 48 89 84 24 80 00 00 00 <49> bc 00 00 00 00 00 fc ff df 4c 8d 74 24 60 48 c7 44 24 20 b3 8a
RSP: 0018:ffffc90000aa7a60 EFLAGS: 00000286
RAX: ed2092ad37b76900 RBX: ffffffff8a5ae778 RCX: 0000000000000010
RDX: 1ffff1100b1dbe59 RSI: 0000000000000201 RDI: ffffffff8a5ae778
RBP: ffffc90000aa7b38 R08: dffffc0000000000 R09: fffffbfff2092a5f
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880228dcc80
R13: dffffc0000000000 R14: ffff888022d48400 R15: 0000000000000201
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31d21000 CR3: 000000000ce8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:125 [inline]
 _raw_spin_lock_bh+0x18/0x40 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 batadv_nc_purge_paths+0xe8/0x3b0 net/batman-adv/network-coding.c:442
 batadv_nc_worker+0x361/0x610 net/batman-adv/network-coding.c:722
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/10 03:04 linux-6.1.y 61adba85cc40 6ee49f2e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in rtnetlink_rcv_msg
2024/03/07 08:06 linux-6.1.y 61adba85cc40 f39a7eed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in rtnetlink_rcv_msg
2024/03/06 01:04 linux-6.1.y a3eb3a74aa8c f39a7eed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in rtnetlink_rcv_msg
2024/01/27 00:38 linux-6.1.y 883d1a956208 cc4a4020 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in rtnetlink_rcv_msg
* Struck through repros no longer work on HEAD.