[v5.15] INFO: task hung in nsim_dev_trap_report_work (2)
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syzbot
3:37 AM (7 hours ago) 3:37 AM
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1483bcc2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=fd06e44aa89238f5cd12
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image: https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fd06e4...@syzkaller.appspotmail.com
INFO: task kworker/1:3:4193 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3 state:D stack:24736 pid: 4193 ppid: 2 flags:0x00004000
Workqueue: events nsim_dev_trap_report_work
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
nsim_dev_trap_report_work+0x56/0xb40 drivers/net/netdevsim/dev.c:757
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
INFO: task syz-executor:11019 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:21792 pid:11019 ppid: 1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
new_device_store+0x13c/0x740 drivers/net/netdevsim/bus.c:295
kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdb5677a1ff
RSP: 002b:00007fff7b0ec980 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fdb5677a1ff
RDX: 0000000000000003 RSI: 00007fff7b0ec9d0 RDI: 0000000000000005
RBP: 00007fdb568012ef R08: 0000000000000000 R09: 00007fff7b0ec7d7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fff7b0ec9d0 R14: 00007fdb57500620 R15: 0000000000000003
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3953:
#0: ffff88802bd8c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:3/4193:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90002e5fd00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff88805c043400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xb40 drivers/net/netdevsim/dev.c:757
3 locks held by kworker/0:5/4247:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000315fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
2 locks held by kworker/1:10/4324:
#0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000333fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
5 locks held by kworker/u4:7/4416:
#0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900034efd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589
#3: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xc8/0x360 net/ipv4/ip_tunnel.c:1132
#4: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#4: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845
3 locks held by kworker/0:10/7153:
#0: ffff888016871938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000309fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x81/0xa50 net/wireless/reg.c:2437
3 locks held by kworker/0:11/7157:
#0: ffff88802ae3d938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900030ffd00 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4654
4 locks held by syz-executor/11019:
#0: ffff88807f240460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590
#1: ffff88806506b888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
#2: ffff888023118918 (kn->active#297){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
#3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x13c/0x740 drivers/net/netdevsim/bus.c:295
7 locks held by syz-executor/11043:
#0: ffff88807f240460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590
#1: ffff8880625aac88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
#2: ffff888023118a00 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
#3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344
#4: ffff88805c047178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
#4: ffff88805c047178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline]
#4: ffff88805c047178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb0/0x750 drivers/base/dd.c:1259
#5: ffff88805c043400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
#5: ffff88805c043400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x115/0x240 drivers/net/netdevsim/dev.c:1561
#6: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x86b/0xa40 net/core/dev.c:10696
1 lock held by syz.5.1741/11212:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440
2 locks held by syz.7.1742/11222:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
1 lock held by syz.0.1747/11237:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440
2 locks held by syz-executor/11241:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
2 locks held by syz-executor/11242:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
2 locks held by syz-executor/11250:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
2 locks held by syz-executor/11254:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
1 lock held by syz-executor/11259:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11266:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11269:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11274:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11280:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11284:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11289:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11290:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11296:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:50 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x102c/0x1d90 arch/x86/kernel/unwind_orc.c:448
Code: 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ff e8 f2 ab 87 00 4d 89 37 e9 3f 01 00 00 49 89 d7 49 89 d5 <4c> 89 e0 4c 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83
RSP: 0018:ffffc90000d36968 EFLAGS: 00000287
RAX: ffffffff8dc62de0 RBX: ffffc90000d36a28 RCX: ffffffff8dc62de8
RDX: ffffffff8dc62dd4 RSI: ffffffff8e58fb8e RDI: 0000000000000001
RBP: ffffffff87d922df R08: 000000000000000a R09: 0000000000000010
R10: fffff520001a6d51 R11: 1ffff920001a6d4f R12: ffffffff8dc62df8
R13: ffffffff8dc62de8 R14: ffffffff8dc62de4 R15: ffffffff8dc62de4
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005559b6013f70 CR3: 000000007d88b000 CR4: 00000000003506f0
DR0: 0000000000000008 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<TASK>
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
slab_alloc_node mm/slub.c:3225 [inline]
slab_alloc mm/slub.c:3233 [inline]
kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
skb_ext_maybe_cow net/core/skbuff.c:6509 [inline]
skb_ext_add+0x1c1/0x910 net/core/skbuff.c:6575
nf_bridge_unshare net/bridge/br_netfilter_hooks.c:165 [inline]
br_nf_forward_ip+0xc2/0x10a0 net/bridge/br_netfilter_hooks.c:687
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584
nf_hook include/linux/netfilter.h:257 [inline]
NF_HOOK+0x1eb/0x370 include/linux/netfilter.h:300
__br_forward+0x41f/0x600 net/bridge/br_forward.c:115
br_handle_frame_finish+0x1018/0x12c0 net/bridge/br_input.c:180
br_nf_hook_thresh+0x3b2/0x480 net/bridge/br_netfilter_hooks.c:1155
br_nf_pre_routing_finish_ipv6+0x903/0xc80 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:302 [inline]
br_nf_pre_routing_ipv6+0x359/0x650 net/bridge/br_netfilter_ipv6.c:237
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:242 [inline]
br_handle_frame+0x89b/0x1180 net/bridge/br_input.c:384
__netif_receive_skb_core+0xfb0/0x35d0 net/core/dev.c:5419
__netif_receive_skb_one_core net/core/dev.c:5523 [inline]
__netif_receive_skb+0x74/0x290 net/core/dev.c:5639
process_backlog+0x364/0x780 net/core/dev.c:6516
__napi_poll+0xc0/0x430 net/core/dev.c:7075
napi_poll net/core/dev.c:7142 [inline]
net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232
handle_softirqs+0x328/0x820 kernel/softirq.c:576
run_ksoftirqd+0x98/0xf0 kernel/softirq.c:943
smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
---
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syzbot found the following issue on:
HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1483bcc2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=fd06e44aa89238f5cd12
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image: https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fd06e4...@syzkaller.appspotmail.com
INFO: task kworker/1:3:4193 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3 state:D stack:24736 pid: 4193 ppid: 2 flags:0x00004000
Workqueue: events nsim_dev_trap_report_work
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
nsim_dev_trap_report_work+0x56/0xb40 drivers/net/netdevsim/dev.c:757
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
INFO: task syz-executor:11019 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:21792 pid:11019 ppid: 1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
new_device_store+0x13c/0x740 drivers/net/netdevsim/bus.c:295
kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdb5677a1ff
RSP: 002b:00007fff7b0ec980 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fdb5677a1ff
RDX: 0000000000000003 RSI: 00007fff7b0ec9d0 RDI: 0000000000000005
RBP: 00007fdb568012ef R08: 0000000000000000 R09: 00007fff7b0ec7d7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fff7b0ec9d0 R14: 00007fdb57500620 R15: 0000000000000003
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3953:
#0: ffff88802bd8c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:3/4193:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90002e5fd00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff88805c043400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xb40 drivers/net/netdevsim/dev.c:757
3 locks held by kworker/0:5/4247:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000315fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
2 locks held by kworker/1:10/4324:
#0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000333fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
5 locks held by kworker/u4:7/4416:
#0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900034efd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589
#3: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xc8/0x360 net/ipv4/ip_tunnel.c:1132
#4: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#4: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845
3 locks held by kworker/0:10/7153:
#0: ffff888016871938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000309fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x81/0xa50 net/wireless/reg.c:2437
3 locks held by kworker/0:11/7157:
#0: ffff88802ae3d938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900030ffd00 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4654
4 locks held by syz-executor/11019:
#0: ffff88807f240460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590
#1: ffff88806506b888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
#2: ffff888023118918 (kn->active#297){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
#3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x13c/0x740 drivers/net/netdevsim/bus.c:295
7 locks held by syz-executor/11043:
#0: ffff88807f240460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590
#1: ffff8880625aac88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:287
#2: ffff888023118a00 (kn->active#296){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x208/0x4c0 fs/kernfs/file.c:288
#3: ffffffff8cb725e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x380 drivers/net/netdevsim/bus.c:344
#4: ffff88805c047178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
#4: ffff88805c047178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline]
#4: ffff88805c047178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb0/0x750 drivers/base/dd.c:1259
#5: ffff88805c043400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
#5: ffff88805c043400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x115/0x240 drivers/net/netdevsim/dev.c:1561
#6: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x86b/0xa40 net/core/dev.c:10696
1 lock held by syz.5.1741/11212:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440
2 locks held by syz.7.1742/11222:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
1 lock held by syz.0.1747/11237:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440
2 locks held by syz-executor/11241:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
2 locks held by syz-executor/11242:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
2 locks held by syz-executor/11250:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
2 locks held by syz-executor/11254:
#0: ffffffff8d22cd10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x224/0x6b0 net/ipv4/ip_tunnel.c:1083
1 lock held by syz-executor/11259:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11266:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11269:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11274:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11280:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11284:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11289:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11290:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
1 lock held by syz-executor/11296:
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7a5/0xe90 net/core/rtnetlink.c:5681
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:50 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x102c/0x1d90 arch/x86/kernel/unwind_orc.c:448
Code: 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ff e8 f2 ab 87 00 4d 89 37 e9 3f 01 00 00 49 89 d7 49 89 d5 <4c> 89 e0 4c 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83
RSP: 0018:ffffc90000d36968 EFLAGS: 00000287
RAX: ffffffff8dc62de0 RBX: ffffc90000d36a28 RCX: ffffffff8dc62de8
RDX: ffffffff8dc62dd4 RSI: ffffffff8e58fb8e RDI: 0000000000000001
RBP: ffffffff87d922df R08: 000000000000000a R09: 0000000000000010
R10: fffff520001a6d51 R11: 1ffff920001a6d4f R12: ffffffff8dc62df8
R13: ffffffff8dc62de8 R14: ffffffff8dc62de4 R15: ffffffff8dc62de4
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005559b6013f70 CR3: 000000007d88b000 CR4: 00000000003506f0
DR0: 0000000000000008 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<TASK>
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
slab_alloc_node mm/slub.c:3225 [inline]
slab_alloc mm/slub.c:3233 [inline]
kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
skb_ext_maybe_cow net/core/skbuff.c:6509 [inline]
skb_ext_add+0x1c1/0x910 net/core/skbuff.c:6575
nf_bridge_unshare net/bridge/br_netfilter_hooks.c:165 [inline]
br_nf_forward_ip+0xc2/0x10a0 net/bridge/br_netfilter_hooks.c:687
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0xb9/0x200 net/netfilter/core.c:584
nf_hook include/linux/netfilter.h:257 [inline]
NF_HOOK+0x1eb/0x370 include/linux/netfilter.h:300
__br_forward+0x41f/0x600 net/bridge/br_forward.c:115
br_handle_frame_finish+0x1018/0x12c0 net/bridge/br_input.c:180
br_nf_hook_thresh+0x3b2/0x480 net/bridge/br_netfilter_hooks.c:1155
br_nf_pre_routing_finish_ipv6+0x903/0xc80 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:302 [inline]
br_nf_pre_routing_ipv6+0x359/0x650 net/bridge/br_netfilter_ipv6.c:237
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:242 [inline]
br_handle_frame+0x89b/0x1180 net/bridge/br_input.c:384
__netif_receive_skb_core+0xfb0/0x35d0 net/core/dev.c:5419
__netif_receive_skb_one_core net/core/dev.c:5523 [inline]
__netif_receive_skb+0x74/0x290 net/core/dev.c:5639
process_backlog+0x364/0x780 net/core/dev.c:6516
__napi_poll+0xc0/0x430 net/core/dev.c:7075
napi_poll net/core/dev.c:7142 [inline]
net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232
handle_softirqs+0x328/0x820 kernel/softirq.c:576
run_ksoftirqd+0x98/0xf0 kernel/softirq.c:943
smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
---
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