INFO: task syz.1.460:7771 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.460 state:D
stack:26032 pid:7771 tgid:7769 ppid:5853 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5352 [inline]
__schedule+0x1665/0x5590 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7047 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7062
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119
rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114
__down_read_common kernel/locking/rwsem.c:1291 [inline]
__down_read kernel/locking/rwsem.c:1304 [inline]
down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570
mmap_read_lock include/linux/mmap_lock.h:592 [inline]
exit_mm+0x73/0x250 kernel/exit.c:557
do_exit+0x8b9/0x2490 kernel/exit.c:962
do_group_exit+0x21b/0x2d0 kernel/exit.c:1116
get_signal+0x1284/0x1330 kernel/signal.c:3035
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff736f9c799
RSP: 002b:00007ff7351f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: 000000000000000b RBX: 00007ff737215fa0 RCX: 00007ff736f9c799
RDX: 0000000000000318 RSI: 00002000000bd000 RDI: 0000000000000004
RBP: 00007ff737032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff737216038 R14: 00007ff737215fa0 R15: 00007ffd3a12de98
INFO: task syz.1.460:7783 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.460 state:D stack:23472 pid:7783 tgid:7769 ppid:5853 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5352 [inline]
__schedule+0x1665/0x5590 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7047 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7062
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119
rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114
__down_read_common kernel/locking/rwsem.c:1291 [inline]
__down_read kernel/locking/rwsem.c:1304 [inline]
down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570
mmap_read_lock include/linux/mmap_lock.h:592 [inline]
exit_mm+0x73/0x250 kernel/exit.c:557
do_exit+0x8b9/0x2490 kernel/exit.c:962
do_group_exit+0x21b/0x2d0 kernel/exit.c:1116
get_signal+0x1284/0x1330 kernel/signal.c:3035
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff736f9c799
RSP: 002b:00007ff7351d5028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000000cfd RBX: 00007ff737216090 RCX: 00007ff736f9c799
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007ff737032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff737216128 R14: 00007ff737216090 R15: 00007ffd3a12de98
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:4/58:
#0: ffff88801c2b6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261
#1: ffffc900015f7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262
#2: ffffffff8fbc6d68 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
#3: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248
#4: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#4: ffffffff8e7638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
3 locks held by kworker/u8:5/86:
#0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261
#1: ffffc900024efc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262
#2: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
3 locks held by kworker/1:2/1222:
#0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261
#1: ffffc9000585fc40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262
#2: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
2 locks held by getty/5599:
#0: ffff88803325d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/7758:
1 lock held by syz.1.460/7771:
#0: ffff88804dc328b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline]
#0: ffff88804dc328b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557
1 lock held by syz.1.460/7783:
#0: ffff88804dc328b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline]
#0: ffff88804dc328b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557
7 locks held by syz-executor/9041:
#0: ffff888035da2410 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff888035da2410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684
#1: ffff88805df89480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
#2: ffff8880293674b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880293674b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
#3: ffffffff8f448200 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff88804da390e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:941 [inline]
#4: ffff88804da390e0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff88804da390e0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304
#5: ffff88804da38258 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1778
#6: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11627 [inline]
#6: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0x7c8/0x1130 net/core/dev.c:11744
4 locks held by syz-executor/9068:
#0: ffff888035da2410 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff888035da2410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684
#1: ffff88802bee8c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
#2: ffff8880293674b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880293674b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
#3: ffffffff8f448200 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
2 locks held by syz-executor/9128:
#0: ffffffff8f3155a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8f3155a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8f3155a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8fbd5d80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0x1002/0x1060 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1335 Comm: kworker/u8:8 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:trace_hardirqs_on+0x23/0x40 kernel/trace/trace_preemptirq.c:78
Code: 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 6d f3 50 11 85 c0 74 14 48 8b 3c 24 e8 88 fe ff ff 65 c7 05 55 f3 50 11 00 00 00 00 68 bc d3 ff 48 8b 3c 24 e9 af b2 e5 09 66 66 66 66 66 66 2e 0f
RSP: 0018:ffffc90005dcf9e0 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000200 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8c284de0 RDI: ffffffff8c284da0
RBP: 0000000000000000 R08: ffffffff90123ff7 R09: 1ffffffff20247fe
R10: dffffc0000000000 R11: fffffbfff20247ff R12: 0000000000000ec0
R13: ffffffff897a2e16 R14: ffffffff897a2e16 R15: ffff88801f6f6780
FS: 0000000000000000(0000) GS:ffff888125535000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0d489e92f8 CR3: 000000004e2bc000 CR4: 00000000003526f0
Call Trace:
__local_bh_enable_ip+0xd0/0x130 kernel/softirq.c:455
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289
process_scheduled_works kernel/workqueue.c:3380 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3466
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245