rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=0a84/1/0x4000000000000000 softirq=15960/15960 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6024/1:b..l rcu: (detected by 0, t=10502 jiffies, g=7553, q=816 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6018 Comm: syz.0.13 Not tainted 6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:135 [inline] RIP: 0010:cpumask_check include/linux/cpumask.h:142 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:646 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1205 [inline] RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x32/0x2f0 kernel/locking/lockdep.c:5879 Code: 41 55 41 54 49 89 f4 53 48 89 fb 48 83 ec 18 65 48 8b 05 b9 fd 3d 12 48 89 44 24 10 31 c0 0f 1f 44 00 00 65 8b 05 d2 fd 3d 12 <83> f8 07 0f 87 38 02 00 00 89 c0 48 0f a3 05 1b 3d 13 0f 0f 82 b1 RSP: 0018:ffffc90000a08cf0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffff9b01c360 RCX: 0000000000000006 RDX: ffffffff9b01c348 RSI: ffffffff84ea0a8c RDI: ffffffff9b01c360 RBP: 0000000000000006 R08: 0000000000000001 R09: fffff52000141198 R10: 0000000000000003 R11: 0000000000000000 R12: ffffffff84ea0a8c R13: dffffc0000000000 R14: ffff88802b112340 R15: 1ffff920001411ac FS: 00007fa2d4fd16c0(0000) GS:ffff8881247c4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3fdab1 CR3: 000000007b17f000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194 debug_object_deactivate+0x1ec/0x3a0 lib/debugobjects.c:888 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline] debug_deactivate kernel/time/hrtimer.c:490 [inline] __run_hrtimer kernel/time/hrtimer.c:1729 [inline] __hrtimer_run_queues+0x46f/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 46 6a 02 f6 48 89 df e8 2e be 02 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 a5 bb f2 f5 65 8b 05 1e 68 40 08 85 c0 74 16 5b RSP: 0018:ffffc9000458f858 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff888032178700 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff8de4e7b1 RDI: ffffffff8c161100 RBP: 0000000000000286 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90aaff97 R11: 0000000000000000 R12: ffff888032178570 R13: ffff888032178740 R14: ffff8880321780e8 R15: ffff8880774f9000 __unix_dgram_recvmsg+0x315/0xc30 net/unix/af_unix.c:2626 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2700 sock_recvmsg_nosec net/socket.c:1065 [inline] ____sys_recvmsg+0x5f6/0x6b0 net/socket.c:2832 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2876 do_recvmmsg+0x2fe/0x750 net/socket.c:2971 __sys_recvmmsg net/socket.c:3045 [inline] __do_sys_recvmmsg net/socket.c:3068 [inline] __se_sys_recvmmsg net/socket.c:3061 [inline] __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3061 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa2d418ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa2d4fd1038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fa2d43b6090 RCX: 00007fa2d418ebe9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000006 RBP: 00007fa2d4211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa2d43b6128 R14: 00007fa2d43b6090 R15: 00007ffdf4e221b8 task:syz.3.16 state:R running task stack:27784 pid:6024 tgid:6024 ppid:5841 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x4/0x350 kernel/locking/lockdep.c:5828 Code: 00 00 00 eb c3 e8 ac d2 fa 09 eb c3 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <41> 57 4d 89 cf 41 56 41 89 f6 41 55 41 89 d5 41 54 45 89 c4 55 89 RSP: 0018:ffffc900045af7e8 EFLAGS: 00000246 RAX: ffffffff816ae56d RBX: 0000000000000001 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e5c1160 RBP: ffffc900045af900 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900045af8b8 R11: 0000000000000000 R12: fffff520008b5f19 R13: ffffc900045af8b8 R14: ffffc900045af8b8 R15: ffffc900045af8c0 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 vfree+0x1fd/0xb50 mm/vmalloc.c:3434 vb2_vmalloc_put drivers/media/common/videobuf2/videobuf2-vmalloc.c:68 [inline] vb2_vmalloc_put+0x7b/0xc0 drivers/media/common/videobuf2/videobuf2-vmalloc.c:63 __vb2_buf_mem_free+0x15a/0x2d0 drivers/media/common/videobuf2/videobuf2-core.c:275 __vb2_free_mem drivers/media/common/videobuf2/videobuf2-core.c:571 [inline] __vb2_queue_free+0x7ee/0xa30 drivers/media/common/videobuf2/videobuf2-core.c:599 vb2_core_queue_release+0x70/0x190 drivers/media/common/videobuf2/videobuf2-core.c:2695 v4l2_m2m_ctx_release+0x1e/0x40 drivers/media/v4l2-core/v4l2-mem2mem.c:1276 vicodec_release+0x9c/0x150 drivers/media/test-drivers/vicodec/vicodec-core.c:1948 v4l2_release+0x235/0x460 drivers/media/v4l2-core/v4l2-dev.c:458 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc69cf8ebe9 RSP: 002b:00007fffcc9f0eb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000001218c RCX: 00007fc69cf8ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fc69d1b7da0 R08: 0000000000000001 R09: 00000009cc9f11af R10: 0000001b30e20000 R11: 0000000000000246 R12: 00007fc69d1b5fac R13: 00007fc69d1b5fa0 R14: ffffffffffffffff R15: 00007fffcc9f0fd0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g7553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=2620 rcu: rcu_preempt kthread starved for 10502 jiffies! g7553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245