syzbot


INFO: task hung in switchdev_deferred_process_work (2)

Status: upstream: reported on 2025/12/02 15:22
Reported-by: syzbot+4e23e13d1bb3927b03f0@syzkaller.appspotmail.com
First crash: 224d, last: 2d11h
Similar bugs (14)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in switchdev_deferred_process_work (2) 1 1 295d 295d 0/3 auto-obsoleted due to no activity on 2025/12/31 08:30
linux-6.1 INFO: task hung in switchdev_deferred_process_work (3) 1 1 55d 55d 0/3 upstream: reported on 2026/05/20 16:07
linux-5.15 INFO: task hung in switchdev_deferred_process_work (5) 1 1 48d 48d 0/3 upstream: reported on 2026/05/27 14:28
upstream INFO: task hung in switchdev_deferred_process_work (2) net 1 C inconclusive 1226 735d 2177d 26/29 fixed on 2024/07/09 19:14
linux-6.6 INFO: task hung in switchdev_deferred_process_work 1 1 356d 356d 0/2 auto-obsoleted due to no activity on 2025/10/31 04:22
upstream INFO: task hung in switchdev_deferred_process_work net 1 35 2468d 3004d 0/29 closed as invalid on 2019/10/23 07:26
upstream INFO: task hung in switchdev_deferred_process_work (3) net 1 C inconclusive 653 9d11h 704d 0/29 upstream: reported C repro on 2024/08/08 21:14
linux-5.15 INFO: task hung in switchdev_deferred_process_work (4) 1 2 207d 215d 0/3 auto-obsoleted due to no activity on 2026/03/29 12:57
linux-5.15 INFO: task hung in switchdev_deferred_process_work 1 1 1189d 1189d 0/3 auto-obsoleted due to no activity on 2023/08/10 05:46
linux-4.19 INFO: task hung in switchdev_deferred_process_work 1 95 1241d 2319d 0/1 upstream: reported on 2020/03/08 04:06
linux-4.14 INFO: task hung in switchdev_deferred_process_work 1 1 1530d 1530d 0/1 auto-obsoleted due to no activity on 2022/09/03 16:45
linux-5.15 INFO: task hung in switchdev_deferred_process_work (2) 1 36 843d 914d 0/3 auto-obsoleted due to no activity on 2024/06/01 16:21
linux-5.15 INFO: task hung in switchdev_deferred_process_work (3) 1 8 627d 770d 0/3 auto-obsoleted due to no activity on 2025/02/02 03:46
linux-6.1 INFO: task hung in switchdev_deferred_process_work 1 8 734d 897d 0/3 auto-obsoleted due to no activity on 2024/10/18 09:59

Sample crash report:
INFO: task kworker/0:2:173 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2     state:D stack:25320 pid:173   ppid:2      flags:0x00004000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task dhcpcd:5433 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:25256 pid:5433  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 vlan_ioctl_handler+0xf1/0x630 net/8021q/vlan.c:580
 sock_ioctl+0x652/0x7e0 net/socket.c:1305
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6e68768378
RSP: 002b:00007ffc3aeb3858 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000055eb0a66d690 RCX: 00007f6e68768378
RDX: 00007ffc3aeb3860 RSI: 0000000000008982 RDI: 000000000000000f
RBP: 00007ffc3aeb3860 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000055eb0a7b0e40 R14: 00007ffc3aec3c70 R15: 000055eb0a66d690
 </TASK>
INFO: task kworker/u4:13:12714 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:13   state:D stack:24272 pid:12714 ppid:2      flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 linkwatch_event+0xe/0x60 net/core/link_watch.c:286
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task kworker/u4:23:12736 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:23   state:D stack:22184 pid:12736 ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 addrconf_dad_work+0xce/0x1550 net/ipv6/addrconf.c:4181
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task syz-executor:13160 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22344 pid:13160 ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 nsim_destroy+0x3f/0x180 drivers/net/netdevsim/netdev.c:417
 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1428
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline]
 nsim_dev_reload_destroy+0x283/0x480 drivers/net/netdevsim/dev.c:1662
 nsim_drv_remove+0x58/0x170 drivers/net/netdevsim/dev.c:1677
 device_remove drivers/base/dd.c:627 [inline]
 __device_release_driver drivers/base/dd.c:1352 [inline]
 device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1375
 bus_remove_device+0x43b/0x520 drivers/base/bus.c:624
 device_del+0x51f/0x910 drivers/base/core.c:3889
 device_unregister+0x20/0xc0 drivers/base/core.c:3930
 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline]
 del_device_store+0x2b6/0x370 drivers/net/netdevsim/bus.c:219
 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc9dd75e68e
RSP: 002b:00007ffd4a99b7d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555577ae3500 RCX: 00007fc9dd75e68e
RDX: 0000000000000001 RSI: 00007ffd4a99b860 RDI: 0000000000000005
RBP: 00007fc9dd8346f2 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd4a99b860 R14: 00007fc9de554620 R15: 0000000000000003
 </TASK>
INFO: task syz.3.2636:13338 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2636      state:D stack:26600 pid:13338 ppid:12817  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:78 [inline]
 rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
 netlink_rcv_skb+0x235/0x4c0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x7b1/0x930 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x61b/0x980 net/socket.c:2595
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1d0/0x2c0 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0ed6d9de59
RSP: 002b:00007f0ed7d07028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0ed7025fa0 RCX: 00007f0ed6d9de59
RDX: 0000000000000000 RSI: 0000200000000940 RDI: 0000000000000004
RBP: 00007f0ed6e33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0ed7026038 R14: 00007f0ed7025fa0 R15: 00007ffe4a9d2398
 </TASK>
INFO: task syz.0.2640:13347 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2640      state:D stack:24936 pid:13347 ppid:12612  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 devinet_ioctl+0x2fc/0x1d70 net/ipv4/devinet.c:1101
 inet_ioctl+0x42b/0x560 net/ipv4/af_inet.c:1000
 sock_do_ioctl+0xfc/0x310 net/socket.c:1220
 sock_ioctl+0x5be/0x7e0 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3610d9de59
RSP: 002b:00007f3611cc7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3611025fa0 RCX: 00007f3610d9de59
RDX: 0000200000000040 RSI: 0000000000008916 RDI: 000000000000000b
RBP: 00007f3610e33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3611026038 R14: 00007f3611025fa0 R15: 00007ffd70445c48
 </TASK>
INFO: task syz.2.2641:13350 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2641      state:D stack:23432 pid:13350 ppid:12346  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 addrconf_set_dstaddr+0xef/0x320 net/ipv6/addrconf.c:2957
 inet6_ioctl+0x164/0x2d0 net/ipv6/af_inet6.c:582
 sock_do_ioctl+0xfc/0x310 net/socket.c:1220
 sock_ioctl+0x5be/0x7e0 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f616519de59
RSP: 002b:00007f6166014028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6165425fa0 RCX: 00007f616519de59
RDX: 0000200000000000 RSI: 0000000000008918 RDI: 0000000000000000
RBP: 00007f6165233e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6165426038 R14: 00007f6165425fa0 R15: 00007fff5788c248
 </TASK>
INFO: task syz-executor:13355 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25384 pid:13355 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:78 [inline]
 rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
 netlink_rcv_skb+0x235/0x4c0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x7b1/0x930 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x4a9/0x6b0 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6c9895e68e
RSP: 002b:00007ffde7e38a38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555564124500 RCX: 00007f6c9895e68e
RDX: 0000000000000028 RSI: 00007f6c99754670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffde7e38ab4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f6c99754670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:13359 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25384 pid:13359 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 rtnl_lock net/core/rtnetlink.c:78 [inline]
 rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
 netlink_rcv_skb+0x235/0x4c0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x7b1/0x930 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x4a9/0x6b0 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdd7c75e68e
RSP: 002b:00007ffef4b66df8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555569917500 RCX: 00007fdd7c75e68e
RDX: 0000000000000028 RSI: 00007fdd7d554670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffef4b66e74 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fdd7d554670 R15: 0000000000000000
 </TASK>
Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings

Showing all locks held in the system:
1 lock held by khungtaskd/28:
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/0:2/173:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #1: ffffc90002ed7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc90002ed7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #2: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by klogd/5128:
 #0: ffff8880b8e3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
2 locks held by dhcpcd/5433:
 #0: ffffffff8e3bab48 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x632/0x7e0 net/socket.c:1303
 #1: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0xf1/0x630 net/8021q/vlan.c:580
2 locks held by getty/5536:
 #0: ffff888031dd20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by kworker/1:5/11597:
 #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #1: ffffc900031c7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc900031c7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #2: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x92/0xd90 net/wireless/reg.c:2463
3 locks held by kworker/u4:13/12714:
 #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #1: ffffc90003687d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc90003687d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #2: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
4 locks held by kworker/u4:20/12728:
3 locks held by kworker/u4:23/12736:
 #0: ffff88802c886d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802c886d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #1: ffffc90003817d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc90003817d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730
 #2: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xce/0x1550 net/ipv6/addrconf.c:4181
7 locks held by syz-executor/13160:
 #0: ffff88802cfc0418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
 #1: ffff88807b3a8888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
 #2: ffff8881427be8c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff8881427be8c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
 #3: ffffffff8dcb6aa8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:209
 #4: ffff88805ed96130 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #4: ffff88805ed96130 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1175 [inline]
 #4: ffff88805ed96130 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1372
 #5: ffff88805ed97250 (&devlink->lock_key#2){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1676
 #6: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3f/0x180 drivers/net/netdevsim/netdev.c:417
1 lock held by syz.3.2636/13338:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz.0.2640/13347:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2fc/0x1d70 net/ipv4/devinet.c:1101
1 lock held by syz.2.2641/13350:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_set_dstaddr+0xef/0x320 net/ipv6/addrconf.c:2957
1 lock held by syz-executor/13355:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13359:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13362:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13365:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13372:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13376:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13374:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13388:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13396:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13400:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473
1 lock held by syz-executor/13402:
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3d5b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf59/0xfa0 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 13117 Comm: kworker/u4:25 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:218 [inline]
RIP: 0010:unwind_next_frame+0x24b/0x2990 arch/x86/kernel/unwind_orc.c:494
Code: f0 4c 8d 24 85 7c 6d b4 8f 4c 89 e0 48 c1 e8 03 48 bb 00 00 00 00 00 fc ff df 0f b6 04 18 84 c0 0f 85 03 22 00 00 45 8b 24 24 <44> 89 f0 ff c0 48 8d 2c 85 7c 6d b4 8f 48 89 e8 48 c1 e8 03 0f b6
RSP: 0018:ffffc900046c7158 EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff888024d70000 RSI: 000000000008ff9e RDI: 000000000009c000
RBP: 000000000009c000 R08: ffffc900046c72f0 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000000 R12: 000000000019ac47
R13: 000000000009c001 R14: 000000000008ff9e R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54a124b28a CR3: 000000000cf32000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc+0xb7/0x240 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 ieee802_11_parse_elems_full+0xb9/0x20c0 net/mac80211/util.c:1616
 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2337 [inline]
 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2344 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1609 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x4b7/0x2dc0 net/mac80211/ibss.c:1642
 ieee80211_iface_process_skb net/mac80211/iface.c:1655 [inline]
 ieee80211_iface_work+0x730/0xc90 net/mac80211/iface.c:1709
 cfg80211_wiphy_work+0x228/0x260 net/wireless/core.c:437
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/12 05:01 linux-6.6.y da47cbc25466 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/05/20 06:33 linux-6.6.y eac8889a3a1c 0909d65f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/05/20 04:57 linux-6.6.y eac8889a3a1c 0909d65f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/04/18 20:13 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/04/13 03:20 linux-6.6.y 8cee53b8eaeb 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/04/02 05:48 linux-6.6.y c09fbcd31ae6 0cb124d5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/03/31 05:00 linux-6.6.y c09fbcd31ae6 d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/01/23 05:50 linux-6.6.y cbb31f77b879 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2026/01/19 09:51 linux-6.6.y cbb31f77b879 a9fc5226 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in switchdev_deferred_process_work
2026/01/09 12:01 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
2025/12/02 15:21 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in switchdev_deferred_process_work
* Struck through repros no longer work on HEAD.