INFO: task hung in rtnl_dumpit (2)

Status: premoderation: reported on 2026/05/26 05:49
Reported-by: syzbot+5247b39e3dcf11fe7323@syzkaller.appspotmail.com
First crash: 69d, last: 69d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 INFO: task hung in rtnl_dumpit 1 2 332d 388d 0/1 auto-obsoleted due to no activity on 2025/12/03 19:43

Sample crash report:
INFO: task dhcpcd:149 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:0     pid:149   tgid:149   ppid:148    flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x14ce/0x2100 kernel/sched/core.c:7893
 __schedule_loop kernel/sched/core.c:7974 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7989
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnl_dumpit+0xa1/0x240 net/core/rtnetlink.c:6537
 netlink_dump+0x6c5/0xee0 net/netlink/af_netlink.c:2320
 __netlink_dump_start+0x6f8/0x980 net/netlink/af_netlink.c:2435
 netlink_dump_start include/linux/netlink.h:339 [inline]
 rtnetlink_dump_start net/core/rtnetlink.c:6567 [inline]
 rtnetlink_rcv_msg+0x737/0xa40 net/core/rtnetlink.c:6634
 netlink_rcv_skb+0x256/0x4f0 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x68d/0x700 net/socket.c:2216
 __do_sys_sendto net/socket.c:2228 [inline]
 __se_sys_sendto net/socket.c:2224 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2224
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f7c7b811407
RSP: 002b:00007ffcdc519580 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f7c7b787740 RCX: 00007f7c7b811407
RDX: 0000000000000014 RSI: 00007ffcdc519610 RDI: 0000000000000016
RBP: 00007ffcdc5195f4 R08: 00007ffcdc5195f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffcdc539f00
R13: 00007f7c7b7876c8 R14: 00007ffcdc5196f0 R15: 00007ffcdc529cd0
 </TASK>
INFO: task kworker/u8:3:309 blocked for more than 125 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D stack:0     pid:309   tgid:309   ppid:2      flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x14ce/0x2100 kernel/sched/core.c:7893
 __schedule_loop kernel/sched/core.c:7974 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7989
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 linkwatch_event+0x12/0x60 net/core/link_watch.c:285
 process_one_work kernel/workqueue.c:3261 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342
 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task kworker/u8:17:880 blocked for more than 127 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:17   state:D stack:0     pid:880   tgid:880   ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x14ce/0x2100 kernel/sched/core.c:7893
 __schedule_loop kernel/sched/core.c:7974 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7989
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
 addrconf_verify_work+0x1d/0x50 net/ipv6/addrconf.c:4774
 process_one_work kernel/workqueue.c:3261 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342
 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423
 kthread+0x2c9/0x370 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor:933 blocked for more than 128 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:933   tgid:933   ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x14ce/0x2100 kernel/sched/core.c:7893
 __schedule_loop kernel/sched/core.c:7974 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7989
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x256/0x4f0 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x68d/0x700 net/socket.c:2216
 __do_sys_sendto net/socket.c:2228 [inline]
 __se_sys_sendto net/socket.c:2224 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2224
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f402ed57fd7
RSP: 002b:00007ffd1307fe10 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555559d4a500 RCX: 00007f402ed57fd7
RDX: 000000000000002c RSI: 00007f402fb44670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd1307fe74 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f402fb44670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:934 blocked for more than 132 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:934   tgid:934   ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6026 [inline]
 __schedule+0x14ce/0x2100 kernel/sched/core.c:7893

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/26 05:48 android16-6.12 28ab3740535f c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in rtnl_dumpit
* Struck through repros no longer work on HEAD.