INFO: task syz.6.12730:19429 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.12730 state:D stack:27360 pid:19429 tgid:19428 ppid:16406 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821 nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1798 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f95c499ce59 RSP: 002b:00007f95c57bf028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f95c4c15fa0 RCX: 00007f95c499ce59 RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000005 RBP: 00007f95c4a32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95c4c16038 R14: 00007f95c4c15fa0 R15: 00007ffd8f39b508 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 20119 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__wrmsrq arch/x86/include/asm/msr.h:80 [inline] RIP: 0010:arch_inlined_clockevent_set_next_coupled arch/x86/include/asm/clock_inlined.h:19 [inline] RIP: 0010:clockevent_set_next_coupled kernel/time/clockevents.c:318 [inline] RIP: 0010:clockevents_program_event+0x1b9/0x630 kernel/time/clockevents.c:360 Code: 3c 24 4c 89 fe e8 67 b5 fc ff 84 c0 0f 84 da 00 00 00 e8 aa ad 0f 00 48 8b 44 24 40 48 89 c2 48 c1 ea 20 b9 e0 06 00 00 0f 30 <4c> 8b 64 24 10 43 c6 44 2c 04 f8 31 c0 48 c7 44 24 20 0e 36 e0 45 RSP: 0018:ffffc90000a08b60 EFLAGS: 00000006 RAX: 00000244692d951f RBX: ffff8880b8723c80 RCX: 00000000000006e0 RDX: 0000000000000244 RSI: 0000000000000014 RDI: 0000000000000040 RBP: ffffc90000a08c20 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000100 R12: ffff8880b8723cc8 R13: dffffc0000000000 R14: 0000000000000004 R15: 0000010538426c70 FS: 0000000000000000(0000) GS:ffff88812537b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558f8911fee8 CR3: 000000000e746000 CR4: 00000000003526f0 Call Trace: hrtimer_rearm kernel/time/hrtimer.c:2141 [inline] __hrtimer_rearm_deferred+0x26c/0x420 kernel/time/hrtimer.c:2161 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline] irqentry_exit+0x8b7/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:206 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ba 44 f7 f5 48 89 df e8 12 ba f7 f5 e8 8d 76 23 f6 fb bf 01 00 00 00 72 d1 e8 f5 65 8b 05 bb a3 8f 07 85 c0 74 07 5b c3 cc cc cc cc RSP: 0018:ffffc90000a08d70 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffff8880b8727100 RCX: 0000000000000105 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: 0000000000000001 RBP: ffffc90000a08f00 R08: ffffffff903114f7 R09: 1ffffffff206229e R10: dffffc0000000000 R11: fffffbfff206229f R12: dffffc0000000000 R13: ffff8880b8727148 R14: 0000000000000000 R15: 0000000000000000 __run_timer_base+0x1ea/0x8b0 kernel/time/timer.c:2387 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0x103/0x170 kernel/time/timer.c:2406 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 9d ba f7 f5 f7 c3 00 02 00 00 74 05 e8 10 77 23 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e4 d1 e8 f5 65 8b 05 2d a4 8f 07 85 c0 74 18 5b 41 5e e9 91 48 RSP: 0018:ffffc900037efab0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000206 RCX: 0000000080000004 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: 0000000000000001 RBP: 00000000000003b1 R08: ffffffff903114f7 R09: 1ffffffff206229e R10: dffffc0000000000 R11: fffffbfff206229f R12: 1ffff110170e8240 R13: ffff88823fff8170 R14: ffff88823fff8700 R15: ffff8880b8741200 free_frozen_page_commit+0x63a/0x11d0 mm/page_alloc.c:2876 __free_frozen_pages+0x744/0xd20 mm/page_alloc.c:2965 vfree+0x1fd/0x330 mm/vmalloc.c:3472 kcov_put kernel/kcov.c:444 [inline] kcov_close+0x28/0x50 kernel/kcov.c:543 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 __do_sys_exit_group kernel/exit.c:1158 [inline] __se_sys_exit_group kernel/exit.c:1156 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1156 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efebd99ce59 Code: Unable to access opcode bytes at 0x7efebd99ce2f. RSP: 002b:00007ffc0a4626f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007efebda33db7 RCX: 00007efebd99ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043 RBP: 00007efebda33dc9 R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00000000000927c0 R14: 0000000000110181 R15: 00007ffc0a4628a0 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog