rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ab44/1/0x4000000000000000 softirq=28408/28409 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=24221, q=384 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8039 Comm: sed Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x66/0x70 kernel/kcov.c:235 Code: 82 48 16 00 00 83 f8 02 75 20 48 8b 8a 50 16 00 00 8b 92 4c 16 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 c5 3e bb 09 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a08e00 EFLAGS: 00000046 RAX: 0000000000010001 RBX: ffff888025aa1300 RCX: ffffffff81aac267 RDX: ffff888026b824c0 RSI: ffffffff81aac275 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 000000000000001f R10: 0000000000000001 R11: ffff888026b82ff0 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880b8528440 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124a09000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdf38acf30 CR3: 0000000047146000 CR4: 00000000003526f0 Call Trace: __remove_hrtimer+0xf5/0x290 kernel/time/hrtimer.c:1115 __run_hrtimer kernel/time/hrtimer.c:1757 [inline] __hrtimer_run_queues+0x55f/0xc40 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x183/0x2d0 kernel/locking/lockdep.c:5893 Code: 0f c1 05 58 c3 17 12 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 ed 7b 17 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0018:ffffc90003c0f9f0 EFLAGS: 00000206 RAX: 837df38e0e4d6600 RBX: ffffffff8e3c9620 RCX: ffffc90003c0f9fc RDX: 0000000000000000 RSI: ffffffff8da9be65 RDI: ffffffff8bf23a80 RBP: 0000000000004002 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000005 R12: ffffffff845dd1b7 R13: 0000000000000206 R14: ffff888026b824c0 R15: 0000000000000001 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] avc_has_perm_noaudit+0x11c/0x3b0 security/selinux/avc.c:1165 avc_has_perm+0xbe/0x1f0 security/selinux/avc.c:1195 inode_has_perm+0x166/0x1d0 security/selinux/hooks.c:1687 file_has_perm+0x2e2/0x350 security/selinux/hooks.c:1783 file_map_prot_check+0x24e/0x360 security/selinux/hooks.c:3971 selinux_mmap_file+0x143/0x1b0 security/selinux/hooks.c:4007 security_mmap_file+0x82a/0x990 security/security.c:2504 vm_mmap_pgoff+0xec/0x470 mm/util.c:575 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:604 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2847292242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007ffdf38ac5d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f28471b4000 RCX: 00007f2847292242 RDX: 0000000000000005 RSI: 0000000000086000 RDI: 00007f28471b4000 RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000010000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffdf38ac628 R13: 00007f28472660c0 R14: 00007ffdf38ac9e0 R15: 00000fffbe7158be rcu: rcu_preempt kthread starved for 10502 jiffies! g24221 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28408 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 8035 Comm: syz.4.532 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xdf6/0x15e0 kernel/smp.c:877 Code: 80 55 0c 00 85 ed 74 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 b5 5a 0c 00 f3 90 41 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 b6 RSP: 0018:ffffc900050a7720 EFLAGS: 00000202 RAX: 0000000000000002 RBX: ffff8880b8540cc0 RCX: ffffffff81b289e1 RDX: ffff888028674980 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffed10170a8199 R14: 0000000000000001 R15: 0000000000000001 FS: 00007fd7744636c0(0000) GS:ffff888124909000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2a2e8c CR3: 0000000048cd9000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x2f0/0x12c0 arch/x86/mm/tlb.c:1472 dup_mmap+0xd04/0x20e0 mm/mmap.c:1866 dup_mm kernel/fork.c:1529 [inline] copy_mm kernel/fork.c:1581 [inline] copy_process+0x3b9f/0x7430 kernel/fork.c:2221 kernel_clone+0xfc/0x910 kernel/fork.c:2651 __do_sys_clone+0xce/0x120 kernel/fork.c:2792 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd77358f749 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:00007fd774462fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fd7737e5fa0 RCX: 00007fd77358f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fd773613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7737e6038 R14: 00007fd7737e5fa0 R15: 00007ffefc6a2348