INFO: task can't die in vlan_ioctl_handler

Status: upstream: reported syz repro on 2022/05/30 07:14
Subsystems: net
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+6db61674290152a463a0@syzkaller.appspotmail.com
First crash: 1783d, last: 2h56m
Cause bisection: failed (error log, bisect log)
  
Fix bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
18f761a5 patching 💥 INFO: task can't die in vlan_ioctl_handler 2026/10/02 17:50 2026/10/02 17:50 2026/10/02 18:33 57bbd979
d3d5ae12 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: task can't die in vlan_ioctl_handler 2026/05/17 04:30 2026/05/17 04:30 2026/05/17 05:57 de5aae85
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] INFO: task can't die in vlan_ioctl_handler 0 (2) 2026/01/05 23:13
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in vlan_ioctl_handler (3) 1 1 226d 226d 0/3 auto-obsoleted due to no activity on 2026/06/10 21:41
linux-5.15 INFO: task hung in vlan_ioctl_handler (2) 1 6 797d 871d 0/3 auto-obsoleted due to no activity on 2024/11/16 16:16
linux-5.15 INFO: task hung in vlan_ioctl_handler (3) 1 1 25d 25d 0/3 upstream: reported on 2026/09/19 07:04
linux-6.1 INFO: task hung in vlan_ioctl_handler (4) 1 1 14h23m 14h23m 0/3 upstream: reported on 2026/10/14 07:52
linux-6.1 INFO: task hung in vlan_ioctl_handler 1 3 874d 993d 0/3 auto-obsoleted due to no activity on 2024/08/31 19:57
linux-5.15 INFO: task hung in vlan_ioctl_handler 1 2 1100d 1140d 0/3 auto-obsoleted due to no activity on 2024/01/18 16:24
linux-6.1 INFO: task hung in vlan_ioctl_handler (2) 1 1 675d 675d 0/3 auto-obsoleted due to no activity on 2025/03/18 20:20
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/05/28 06:06 1h34m retest repro net-next log
2026/01/20 03:02 23m retest repro net-next report log

Sample crash report:
INFO: task dhcpcd:5493 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:25208 pid:5493  tgid:5493  ppid:1      task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:579
 sock_ioctl+0x610/0x790 net/socket.c:1339
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf8811e378
RSP: 002b:00007ffdc6aa60d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00005605e1c82ba0 RCX: 00007fcf8811e378
RDX: 00007ffdc6aa60e0 RSI: 0000000000008982 RDI: 000000000000000f
RBP: 00007ffdc6aa60e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00005605e1ddbd40 R14: 00007ffdc6aa6b30 R15: 00005605e1c82ba0
 </TASK>
INFO: task kworker/u8:16:6446 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:16   state:D stack:25336 pid:6446  tgid:6446  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
INFO: task syz-executor:6457 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:22392 pid:6457  tgid:6457  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184

Crashes (243):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/05 23:13 net-next c303e8b86d9d d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2021/11/26 12:13 linux-next f81e94e91878 63eeac02 .config console log report info ci-upstream-linux-next-kasan-gce-root INFO: task can't die in vlan_ioctl_handler
2026/10/13 15:47 upstream 24a19b953e2a 7321cd29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/06 08:59 upstream 2c3418fffa9d f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/09/30 13:17 upstream 551c722f4080 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/09/28 20:19 upstream 72d3fcf802c4 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/09/22 22:04 upstream c4e9f74da438 3e2106e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/22 12:00 upstream f0100363d8c3 e12281bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/20 14:56 upstream 518e5b794c06 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/09/14 16:47 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/09/08 14:04 upstream 28924df2a08f 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/01 09:31 upstream bf1079577a11 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/08/27 08:13 upstream 502d45774af0 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in vlan_ioctl_handler
2026/08/25 15:59 upstream 66498c75b4f8 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/08/25 04:41 upstream 66498c75b4f8 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/02/17 05:58 upstream c22e26bd0906 e439b951 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in vlan_ioctl_handler
2026/02/13 01:43 upstream 37a93dd5c49b 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in vlan_ioctl_handler
2025/01/23 17:16 upstream 7004a2e46d16 f6a35ef3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in vlan_ioctl_handler
2026/10/14 07:40 net 513444cc62e2 7321cd29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/13 13:20 net 8e2fbe0e75d3 7321cd29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/12 10:45 net af32da41b032 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/10 11:36 net af32da41b032 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/09 23:46 net af32da41b032 a8add9cd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/09 22:21 net af32da41b032 a8add9cd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/09 07:04 net 37f12441f557 b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/04 04:39 net 6dc989ea46b9 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/28 01:43 net a7bfaba4823e a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/24 18:43 net ab1404ac8115 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/23 23:29 net 9c572a83037a 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/16 19:59 net ceac0de741bf 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/16 05:20 net 83a945a529d6 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/14 21:27 net e6b6078ea173 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/13 03:18 net e6b6078ea173 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/12 11:54 net e6b6078ea173 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/10 04:55 net a401a9d547c5 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/08 06:14 net 74f27fc8642b 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/07 03:42 net 38b6be101006 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/02 07:40 net 1d2929d0850f 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/08/31 14:18 net 1376afc7660b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/08/31 13:52 net 1376afc7660b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/08/30 03:45 net 2188569e7e1b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/08/25 14:11 net c5f2613e69cc 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/08/24 21:54 net 3e995a30b9e3 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/13 16:57 net-next d7804253678e 7321cd29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/12 23:48 net-next 3a82195416fd 745a967f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/07 20:29 net-next 45ad84d2800e 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/07 14:59 net-next 45ad84d2800e 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/03 01:47 net-next 071876fd5048 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/23 18:28 net-next 944ae66642b7 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/09/03 00:28 net-next c29b37ed7a4d 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/08/26 08:12 net-next 91ec20351349 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/08/25 08:49 net-next 91ec20351349 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in vlan_ioctl_handler
2026/10/14 19:18 linux-next d419d682257d 7321cd29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/09/27 22:27 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in vlan_ioctl_handler
2026/09/25 06:36 linux-next 4c253ac4b29b f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in vlan_ioctl_handler
* Struck through repros no longer work on HEAD.