rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=2744/1/0x4000000000000000 softirq=68599/68600 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=57593, q=207 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13259 Comm: syz.2.2128 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:98 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x180/0x1e0 mm/kasan/generic.c:200 Code: ff ff ff 48 85 d2 74 98 48 01 ea eb 1a 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 83 c0 01 48 39 d0 0f 84 79 ff ff ff 80 38 00 <74> ee e9 57 ff ff ff b8 01 00 00 00 c3 cc cc cc cc 48 29 c3 48 89 RSP: 0018:ffffc90000007d30 EFLAGS: 00000046 RAX: ffffed100f8ae655 RBX: ffffed100f8ae656 RCX: ffffffff81e54159 RDX: ffffed100f8ae656 RSI: 0000000000000004 RDI: ffff88807c5732a8 RBP: ffffed100f8ae655 R08: 0000000000000001 R09: ffffed100f8ae655 R10: ffff88807c5732ab R11: ffffc90000007ff8 R12: 1ffff92000000fab R13: ffff88807c5732b8 R14: ffff8880b8428640 R15: ffff8880b8428690 FS: 00007f5759a5f6c0(0000) GS:ffff888124318000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5758c4f270 CR3: 000000007b408000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x119/0x260 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:342 [inline] advance_sched+0xe5/0xd20 net/sched/sch_taprio.c:930 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/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+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 56 4d 4b f6 48 89 df e8 de 9c 4b f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 a5 ae 3a f6 65 8b 05 ae d8 76 08 85 c0 74 16 5b RSP: 0018:ffffc90005d57d78 EFLAGS: 00000246 RAX: 0000000000000046 RBX: ffffffff9b2023d8 RCX: ffffffff8211aa2f RDX: 0000000000000000 RSI: ffffffff8c1d2780 RDI: ffffffff8b99a792 RBP: 0000000000000293 R08: 0000000000000000 R09: fffffbfff21b44f2 R10: 0000000000000000 R11: ffffffffffffffff R12: 1ffff92000baafb6 R13: 000000000cfca2e2 R14: 000000000cfca2e2 R15: 0000000000000000 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] do_settimeofday64+0x326/0x4d0 kernel/time/timekeeping.c:1665 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1139 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1123 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1123 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5758b9ce59 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:00007f5759a5f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f5758e15fa0 RCX: 00007f5758b9ce59 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f5758c32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5758e16038 R14: 00007f5758e15fa0 R15: 00007fffc5090da8 rcu: rcu_preempt kthread starved for 10500 jiffies! g57593 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27880 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7322 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 13251 Comm: syz.0.2125 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:write_comp_data+0x2b/0x90 kernel/kcov.c:272 Code: 8b 05 19 28 07 12 49 89 f8 49 89 f1 49 89 d2 65 48 8b 3d f0 27 07 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 cc cc cc cc 8b 87 1c 17 00 00 85 c0 74 f1 8b 87 f8 16 00 00 83 RSP: 0018:ffffc90005e6f440 EFLAGS: 00000297 RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81fcc98d RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88802f730000 RBP: ffff8880b8443500 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170886a1 R14: 0000000000000001 R15: ffff8880b853c700 FS: 00007f4cb506f6c0(0000) GS:ffff888124418000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2eba18 CR3: 0000000039f26000 CR4: 00000000003526f0 Call Trace: csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0x5ad/0x16c0 kernel/smp.c:892 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057 on_each_cpu include/linux/smp.h:72 [inline] kernel_tlb_flush_all arch/x86/mm/tlb.c:1517 [inline] flush_tlb_kernel_range+0x1d6/0x220 arch/x86/mm/tlb.c:1538 kasan_release_vmalloc include/linux/kasan.h:593 [inline] kasan_release_vmalloc_node mm/vmalloc.c:2294 [inline] purge_vmap_node+0x2a0/0xb40 mm/vmalloc.c:2306 __purge_vmap_area_lazy+0x90a/0xc00 mm/vmalloc.c:2396 _vm_unmap_aliases+0x40e/0x630 mm/vmalloc.c:2990 change_page_attr_set_clr+0x252/0x4a0 arch/x86/mm/pat/set_memory.c:2101 cpa_set_pages_array arch/x86/mm/pat/set_memory.c:2156 [inline] _set_pages_array+0x1ab/0x2c0 arch/x86/mm/pat/set_memory.c:2527 drm_gem_shmem_get_pages_locked+0x380/0x4b0 drivers/gpu/drm/drm_gem_shmem_helper.c:256 drm_gem_shmem_pin_locked+0x224/0x4f0 drivers/gpu/drm/drm_gem_shmem_helper.c:305 drm_gem_map_attach+0x184/0x270 drivers/gpu/drm/drm_prime.c:621 dma_buf_dynamic_attach.part.0+0x1a8/0x640 drivers/dma-buf/dma-buf.c:1034 dma_buf_dynamic_attach drivers/dma-buf/dma-buf.c:1019 [inline] dma_buf_attach+0x34/0x70 drivers/dma-buf/dma-buf.c:1064 drm_gem_shmem_prime_import_no_map drivers/gpu/drm/drm_gem_shmem_helper.c:949 [inline] drm_gem_shmem_prime_import_no_map+0x67/0x390 drivers/gpu/drm/drm_gem_shmem_helper.c:930 drm_gem_prime_fd_to_handle+0x1a3/0x5e0 drivers/gpu/drm/drm_prime.c:314 drm_prime_fd_to_handle_ioctl+0xd6/0x110 drivers/gpu/drm/drm_prime.c:372 drm_ioctl_kernel+0x1f3/0x3e0 drivers/gpu/drm/drm_ioctl.c:805 drm_ioctl+0x5e6/0xc60 drivers/gpu/drm/drm_ioctl.c:902 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4cb419ce59 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:00007f4cb506f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4cb4416090 RCX: 00007f4cb419ce59 RDX: 0000200000000300 RSI: 00000000c00c642e RDI: 0000000000000006 RBP: 00007f4cb4232e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4cb4416128 R14: 00007f4cb4416090 R15: 00007ffc878a3a98