INFO: task syz.0.183:6571 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.183 state:D stack:25512 pid:6571 ppid:5762 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 perf_pending_task_sync kernel/events/core.c:5242 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5248 put_event kernel/events/core.c:5376 [inline] perf_event_release_kernel+0x842/0x8d0 kernel/events/core.c:5501 perf_release+0x3b/0x40 kernel/events/core.c:5511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x95a/0x2460 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7882bbbd10 RSP: 002b:00007f7883b29a78 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f7882e15fa0 RCX: 00007f7882b9c799 RDX: 00007f7883b29a80 RSI: 00007f7883b29bb0 RDI: 0000000000000021 RBP: 00007f7882c32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7882e16038 R14: 00007f7882e15fa0 R15: 00007ffeaca29218 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5525: #0: ffff88823bcbc8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 1 lock held by syz.6.574/8437: #0: ffff88807b8673a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:155 8 locks held by syz.6.574/8439: 1 lock held by syz.3.579/8453: #0: ffffffff8d137900 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8439 Comm: syz.6.574 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:preempt_count_sub+0x5/0x160 kernel/sched/core.c:5868 Code: 6e ff ff ff 48 c7 c7 b0 23 8b 8e e8 a5 c4 82 00 89 df e9 5b ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 55 <53> 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 80 84 2c 97 48 c1 e8 03 RSP: 0000:ffffc90000006a48 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1f85dad4284c6500 RDX: 0000000000010100 RSI: ffffffff8ac1a6c0 RDI: 0000000000000001 RBP: ffffc90000006be8 R08: ffffffff8e8aeeef R09: 1ffffffff1d15ddd R10: dffffc0000000000 R11: fffffbfff1d15dde R12: ffffc90005747f58 R13: ffffc90000006b60 R14: 0000000000000000 R15: 1ffff92000000d68 FS: 00007f675f0086c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efe45016080 CR3: 000000002bd0f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: kvm_get_running_vcpu virt/kvm/kvm_main.c:5996 [inline] kvm_guest_state+0x3a/0xf0 virt/kvm/kvm_main.c:6013 perf_guest_state include/linux/perf_event.h:1520 [inline] perf_callchain_user+0x22/0x15c0 arch/x86/events/core.c:2918 get_perf_callchain+0x394/0x510 kernel/events/callchain.c:219 perf_callchain kernel/events/core.c:7740 [inline] perf_sample_save_callchain include/linux/perf_event.h:1232 [inline] perf_prepare_sample+0x3c7/0x1df0 kernel/events/core.c:7784 __perf_event_output kernel/events/core.c:7972 [inline] perf_event_output_forward+0x187/0x3e0 kernel/events/core.c:7993 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9718 perf_swevent_hrtimer+0x4aa/0x570 kernel/events/core.c:11188 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x4e1/0xc40 kernel/time/hrtimer.c:1814 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215 Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d bc d4 03 0d 48 89 de 5b e9 33 5f 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 50 99 7c 7e 65 8b 15 51 99 7c 7e 81 e2 00 01 ff 00 74 RSP: 0000:ffffc90000007438 EFLAGS: 00000202 RAX: ffffffff813b34f1 RBX: ffffc900000074b0 RCX: 0000000000000100 RDX: ffff88802d525a00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffff88802d525a00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff86379b87 R13: 00000000000002c0 R14: dffffc0000000000 R15: 1ffff92000000e96 unwind_get_return_address+0x71/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 __netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:717 netdev_alloc_skb include/linux/skbuff.h:3304 [inline] dev_alloc_skb include/linux/skbuff.h:3317 [inline] __ieee80211_beacon_get+0xe17/0x1600 net/mac80211/tx.c:5447 ieee80211_beacon_get_tim+0xbf/0x580 net/mac80211/tx.c:5569 ieee80211_beacon_get include/net/mac80211.h:5440 [inline] mac80211_hwsim_beacon_tx+0x3c7/0x780 drivers/net/wireless/virtual/mac80211_hwsim.c:2265 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:766 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:802 mac80211_hwsim_beacon+0xbb/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2295 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x520/0xc40 kernel/time/hrtimer.c:1814 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline] RIP: 0010:kasan_check_range+0x89/0x290 mm/kasan/generic.c:187 Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 3d 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 8d 01 00 00 49 ff c3 48 ff c3 75 ee e9 1d 01 00 00 44 89 dd RSP: 0000:ffffc90005747348 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff816828c7 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e8aeee8 RBP: ffffc900057474a0 R08: ffffffff8e8aeeef R09: 1ffffffff1d15ddd R10: dffffc0000000000 R11: fffffbfff1d15ddd R12: 0000000000000001 R13: ffffffff8d132060 R14: fffffbfff1d15dde R15: 1ffffffff1d15ddd instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:504 [inline] cpu_online include/linux/cpumask.h:1082 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xb7/0x420 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] page_ext_get+0x3e/0x2b0 mm/page_ext.c:508 page_table_check_set+0x51/0x6e0 mm/page_table_check.c:114 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline] set_ptes include/linux/pgtable.h:238 [inline] copy_present_pte mm/memory.c:979 [inline] copy_pte_range mm/memory.c:1083 [inline] copy_pmd_range mm/memory.c:1168 [inline] copy_pud_range mm/memory.c:1205 [inline] copy_p4d_range mm/memory.c:1229 [inline] copy_page_range+0x24e5/0x3670 mm/memory.c:1323 dup_mmap kernel/fork.c:764 [inline] dup_mm kernel/fork.c:1692 [inline] copy_mm+0x11cb/0x1d50 kernel/fork.c:1741 copy_process+0x16f7/0x3d80 kernel/fork.c:2506 kernel_clone+0x24b/0x8a0 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f675e19c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f675f007fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f675e415fa0 RCX: 00007f675e19c799 RDX: 0000000000000000 RSI: fffffffffffffc70 RDI: 0000000001022000 RBP: 00007f675e232c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f675e416038 R14: 00007f675e415fa0 R15: 00007ffe37b8c918