INFO: task dhcpcd:3933 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:20960 pid:3933 ppid:3932 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline] cgroup_css_set_fork kernel/cgroup/cgroup.c:6432 [inline] cgroup_can_fork+0xc27/0xd30 kernel/cgroup/cgroup.c:6565 copy_process+0x248b/0x4020 kernel/fork.c:2446 kernel_clone+0x225/0x8b0 kernel/fork.c:2757 __do_sys_clone kernel/fork.c:2898 [inline] __se_sys_clone kernel/fork.c:2882 [inline] __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc05a664636 RSP: 002b:00007ffd11705e00 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd11705e08 RCX: 00007fc05a664636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd11726350 R08: 0000000000000000 R09: 0000000000000001 R10: 00007fc05a590a10 R11: 0000000000000246 R12: 00007ffd11705f40 R13: 0000000000000000 R14: 0000000000000000 R15: 000055bd42ab0ac0 INFO: task udevd:4308 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26560 pid:4308 ppid:3637 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline] exit_signals+0x3c0/0x4f0 kernel/signal.c:2963 do_exit+0x578/0x2400 kernel/exit.c:827 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 __do_sys_exit_group kernel/exit.c:1033 [inline] __se_sys_exit_group kernel/exit.c:1031 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f018f0f16c5 RSP: 002b:00007ffee4ec69b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055fa269f2870 RCX: 00007f018f0f16c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055fa269be910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee4ec6a00 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor:4399 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21160 pid:4399 ppid:4396 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 cgroup_lock include/linux/cgroup.h:442 [inline] cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1700 __cgroup_procs_write+0x73/0x350 kernel/cgroup/cgroup.c:5174 cgroup_procs_write+0x23/0x40 kernel/cgroup/cgroup.c:5214 cgroup_file_write+0x2f8/0x660 kernel/cgroup/cgroup.c:4100 kernfs_fop_write_iter+0x3b2/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0fc5d8d97f RSP: 002b:00007ffe0fbb7e80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0fc5d8d97f RDX: 0000000000000001 RSI: 00007ffe0fbb7ed0 RDI: 0000000000000003 RBP: 00007ffe0fbb8440 R08: 0000000000000000 R09: 00007ffe0fbb7cd7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffe0fbb7ed0 R14: 00007ffe0fbb8400 R15: 00007ffe0fbb8440 INFO: task syz-executor:4402 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:22688 pid:4402 ppid:4400 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189 mmap_write_lock include/linux/mmap_lock.h:71 [inline] mpol_rebind_mm+0xbe/0x370 mm/mempolicy.c:386 cpuset_attach+0x284/0x540 kernel/cgroup/cpuset.c:2663 cgroup_migrate_execute+0x7a3/0xf30 kernel/cgroup/cgroup.c:2662 cgroup_attach_task+0x558/0x840 kernel/cgroup/cgroup.c:2953 __cgroup1_procs_write+0x2e0/0x3e0 kernel/cgroup/cgroup-v1.c:522 cgroup_file_write+0x2f8/0x660 kernel/cgroup/cgroup.c:4100 kernfs_fop_write_iter+0x3b2/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f621978d97f RSP: 002b:00007fffc7edd8c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f621978d97f RDX: 0000000000000001 RSI: 00007fffc7edd910 RDI: 0000000000000003 RBP: 00007fffc7edde80 R08: 0000000000000000 R09: 00007fffc7edd717 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007fffc7edd910 R14: 00007fffc7edde40 R15: 00007fffc7edde80 INFO: task udevd:4412 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26560 pid:4412 ppid:3637 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 percpu_rwsem_wait+0x2bd/0x300 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xda/0x120 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:748 [inline] exit_signals+0x3c0/0x4f0 kernel/signal.c:2963 do_exit+0x578/0x2400 kernel/exit.c:827 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 __do_sys_exit_group kernel/exit.c:1033 [inline] __se_sys_exit_group kernel/exit.c:1031 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f018f0f16c5 RSP: 002b:00007ffee4ec69b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055fa269e14d0 RCX: 00007f018f0f16c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055fa269be910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee4ec6a00 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.2.19:4726 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.19 state:D stack:25320 pid:4726 ppid:4403 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189 mmap_write_lock include/linux/mmap_lock.h:71 [inline] exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 __mmput+0x118/0x3c0 kernel/fork.c:1200 exit_mm+0x1e6/0x2c0 kernel/exit.c:565 do_exit+0x8c1/0x2400 kernel/exit.c:867 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff89058eec9 RSP: 002b:00007ff8913bd0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007ff8907e5fa8 RCX: 00007ff89058eec9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff8907e5fa8 RBP: 00007ff8907e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff8907e6038 R14: 00007ffe71238520 R15: 00007ffe71238608 INFO: task syz.0.126:4746 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.126 state:D stack:25728 pid:4746 ppid:4394 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189 mmap_write_lock include/linux/mmap_lock.h:71 [inline] exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 __mmput+0x118/0x3c0 kernel/fork.c:1200 exit_mm+0x1e6/0x2c0 kernel/exit.c:565 do_exit+0x8c1/0x2400 kernel/exit.c:867 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ffafc58eec9 RSP: 002b:00007ffafd38e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007ffafc7e5fa8 RCX: 00007ffafc58eec9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ffafc7e5fa8 RBP: 00007ffafc7e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffafc7e6038 R14: 00007ffe448732a0 R15: 00007ffe44873388 INFO: task syz.3.127:4748 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.127 state:D stack:25728 pid:4748 ppid:4401 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189 mmap_write_lock include/linux/mmap_lock.h:71 [inline] exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 __mmput+0x118/0x3c0 kernel/fork.c:1200 exit_mm+0x1e6/0x2c0 kernel/exit.c:565 do_exit+0x8c1/0x2400 kernel/exit.c:867 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc4a818eec9 RSP: 002b:00007fc4a8f500e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fc4a83e5fa8 RCX: 00007fc4a818eec9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc4a83e5fa8 RBP: 00007fc4a83e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc4a83e6038 R14: 00007ffc0ca37130 R15: 00007ffc0ca37218 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 1 lock held by dhcpcd/3933: #0: ffffffff8cb53810 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x248b/0x4020 kernel/fork.c:2446 2 locks held by getty/4026: #0: ffff88814d386098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 1 lock held by udevd/4308: #0: ffffffff8cb53810 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827 1 lock held by udevd/4333: #0: ffff88807331cc58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88807331cc58 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x141/0x290 mm/mmap.c:2933 1 lock held by syz-executor/4397: #0: ffffffff8cb53810 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827 3 locks held by syz-executor/4399: #0: ffff88807354a460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff88805aad1c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffffffff8cb53628 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline] #2: ffffffff8cb53628 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1700 7 locks held by syz-executor/4402: #0: ffff88807312a460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff88807e2bd488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffffffff8cb53628 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline] #2: ffffffff8cb53628 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1700 #3: ffffffff8c9c7a70 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2476 [inline] #3: ffffffff8c9c7a70 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x183/0x600 kernel/cgroup/cgroup.c:2982 #4: ffffffff8cb53810 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2478 [inline] #4: ffffffff8cb53810 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x199/0x600 kernel/cgroup/cgroup.c:2982 #5: ffffffff8cb61ca8 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xac/0x540 kernel/cgroup/cpuset.c:2647 #6: ffff8880174697d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #6: ffff8880174697d8 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0xbe/0x370 mm/mempolicy.c:386 1 lock held by udevd/4412: #0: ffffffff8cb53810 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827 1 lock held by syz.2.19/4726: #0: ffff88807749e2d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff88807749e2d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 1 lock held by syz.0.126/4746: #0: ffff888077499f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff888077499f58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 1 lock held by syz.3.127/4748: #0: ffff88807749b5d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff88807749b5d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 56 Comm: kworker/u4:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:memset+0x2b/0x40 mm/kasan/shadow.c:47 Code: 41 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 00 00 e8 72 ec ff ff 84 c0 74 11 4c 89 f7 89 ee 48 89 da 5b <41> 5e 5d e9 dd f1 3a 08 31 c0 5b 41 5e 5d c3 66 0f 1f 44 00 00 41 RSP: 0018:ffffc90001577610 EFLAGS: 00000202 RAX: ffff888019a51d01 RBX: ffffc90001577688 RCX: ffffffff81388782 RDX: 0000000000000060 RSI: 0000000000000000 RDI: ffffc90001577688 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff520002aeedd R10: fffff520002aeedd R11: 1ffff920002aeed1 R12: 0000000000000000 R13: ffff888019a51dc0 R14: ffffc90001577688 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0f03e52000 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x32/0x740 arch/x86/kernel/unwind_orc.c:645 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] kmem_cache_alloc_node+0x14d/0x320 mm/slub.c:3404 __alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1271 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x28f/0xaf0 drivers/net/netdevsim/dev.c:851 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295