syzbot


INFO: task hung in __netlink_dump_start (3)

Status: auto-obsoleted due to no activity on 2025/01/17 03:09
Subsystems: net
[Documentation on labels]
First crash: 119d, last: 93d
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __netlink_dump_start (2) net 5 1108d 1190d 0/28 closed as invalid on 2022/02/07 19:19
linux-4.19 INFO: task hung in __netlink_dump_start 1 1689d 1689d 0/1 auto-closed as invalid on 2020/10/04 12:25
upstream INFO: task hung in __netlink_dump_start net 2 1558d 1572d 0/28 auto-closed as invalid on 2021/01/13 23:36
linux-5.15 INFO: task hung in __netlink_dump_start 20 73d 337d 0/3 upstream: reported on 2024/02/18 03:22
linux-4.19 INFO: task hung in __netlink_dump_start (2) 1 1060d 1060d 0/1 auto-closed as invalid on 2022/06/25 14:03
upstream INFO: task hung in rtnetlink_rcv_msg net C inconclusive inconclusive 1970 195d 2159d 26/28 fixed on 2024/07/09 19:14
linux-6.1 INFO: task hung in __netlink_dump_start 16 213d 358d 0/3 auto-obsoleted due to no activity on 2024/09/29 18:06
linux-6.1 INFO: task hung in __netlink_dump_start (2) origin:lts-only syz 3 59d 111d 0/3 upstream: reported syz repro on 2024/10/01 03:35

Sample crash report:
INFO: task syz.2.1584:10819 blocked for more than 145 seconds.
      Not tainted 6.12.0-rc3-syzkaller-00140-g07d6bf634bc8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1584      state:D stack:26800 pid:10819 tgid:10818 ppid:5242   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5322 [inline]
 __schedule+0x1895/0x4b30 kernel/sched/core.c:6682
 __schedule_loop kernel/sched/core.c:6759 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2405
 genl_family_rcv_msg_dumpit net/netlink/genetlink.c:1076 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline]
 genl_rcv_msg+0x88c/0xec0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2551
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:744
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607
 ___sys_sendmsg net/socket.c:2661 [inline]
 __sys_sendmsg+0x292/0x380 net/socket.c:2690
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9fafd7dff9
RSP: 002b:00007f9fb0c54038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9faff35f80 RCX: 00007f9fafd7dff9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007f9fafdf0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9faff35f80 R15: 00007ffce03ebed8
 </TASK>
INFO: task syz.2.1584:10822 blocked for more than 145 seconds.
      Not tainted 6.12.0-rc3-syzkaller-00140-g07d6bf634bc8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1584      state:D stack:25048 pid:10822 tgid:10818 ppid:5242   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5322 [inline]
 __schedule+0x1895/0x4b30 kernel/sched/core.c:6682
 __schedule_loop kernel/sched/core.c:6759 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 nfsd_nl_rpc_status_get_dumpit+0xdc/0x1a60 fs/nfsd/nfsctl.c:1558
 genl_dumpit+0x107/0x1a0 net/netlink/genetlink.c:1027
 netlink_dump+0x647/0xd80 net/netlink/af_netlink.c:2326
 __netlink_dump_start+0x5a2/0x790 net/netlink/af_netlink.c:2441
 genl_family_rcv_msg_dumpit net/netlink/genetlink.c:1076 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline]
 genl_rcv_msg+0x88c/0xec0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2551
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:744
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607
 ___sys_sendmsg net/socket.c:2661 [inline]
 __sys_sendmsg+0x292/0x380 net/socket.c:2690
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9fafd7dff9
RSP: 002b:00007f9fb0c33038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9faff36058 RCX: 00007f9fafd7dff9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007f9fafdf0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9faff36058 R15: 00007ffce03ebed8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/12:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
2 locks held by getty/4986:
 #0: ffff88814c61c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
9 locks held by kworker/1:4/5281:
3 locks held by kworker/1:6/5312:
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffff8880b8728948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987
 #2: ffff88805c33a240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1488
2 locks held by syz.1.1390/10076:
 #0: ffffffff8fd38970 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8ec19008 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1964
2 locks held by syz.2.1584/10819:
 #0: ffffffff8fd38970 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff8880642fd6c8 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2405
3 locks held by syz.2.1584/10822:
 #0: ffffffff8fd38970 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff8880642fd6c8 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2405
 #2: ffffffff8ec19008 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1a60 fs/nfsd/nfsctl.c:1558
3 locks held by syz-executor/11135:
 #0: ffff888065a98d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff888065a98d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698
 #1: ffff888065a98078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183
 #2: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #2: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976
2 locks held by syz-executor/13092:
 #0: ffffffff8fcd2c08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
 #0: ffffffff8fcd2c08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517
 #1: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #1: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
3 locks held by syz-executor/13108:
 #0: ffff88802b230d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff88802b230d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698
 #1: ffff88802b230078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183
 #2: ffffffff8fe3f528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline]
 #2: ffffffff8fe3f528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592
3 locks held by syz.2.2197/13275:
 #0: ffff88807ffacd80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff88807ffacd80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698
 #1: ffff88807ffac078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183
 #2: ffffffff8fe3f528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline]
 #2: ffffffff8fe3f528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592
3 locks held by syz.1.2199/13276:
 #0: ffff8880603e4d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff8880603e4d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698
 #1: ffff8880603e4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5183
 #2: ffffffff8fe3f528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline]
 #2: ffffffff8fe3f528 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc3-syzkaller-00140-g07d6bf634bc8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1038 Comm: kworker/u8:5 Not tainted 6.12.0-rc3-syzkaller-00140-g07d6bf634bc8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: bat_events batadv_tt_purge
RIP: 0010:__lock_acquire+0x473/0x2050 kernel/locking/lockdep.c:5145
Code: 68 83 e7 03 c1 e7 10 09 cf 8b 4c 24 60 83 e1 01 c1 e1 12 c1 e0 14 31 d2 83 7c 24 40 00 0f 95 c2 c1 e2 13 41 c1 e6 15 41 09 d6 <41> 09 c6 41 09 ce 41 09 fe 48 8b 44 24 20 0f b6 04 30 84 c0 0f 85
RSP: 0018:ffffc90003d078d0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 00000000000007c9 RCX: 0000000000040000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 00000000000007c9
RBP: 000000000000000a R08: 00000000000007c9 R09: ffff8880268a64e0
R10: dffffc0000000000 R11: fffffbfff2039fd6 R12: ffff8880268a5a00
R13: 00000000000007c9 R14: 0000000000000000 R15: ffff88805a431798
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558eb97ec220 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 batadv_tt_global_purge net/batman-adv/translation-table.c:2279 [inline]
 batadv_tt_purge+0x11c/0xa40 net/batman-adv/translation-table.c:3561
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/19 03:05 net 07d6bf634bc8 cd6fc0a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in __netlink_dump_start
2024/09/23 14:25 net c8770db2d544 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in __netlink_dump_start
2024/09/24 01:34 net-next 151ac45348af 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in __netlink_dump_start
* Struck through repros no longer work on HEAD.