rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=3924/1/0x4000000000000000 softirq=41488/41488 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=45645, q=245 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12004 Comm: syz.6.1660 Not tainted 6.13.0-rc6-syzkaller-00231-g77a903cd8e5a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x81/0x90 kernel/kcov.c:316 Code: 8d 42 28 4c 39 c8 77 22 89 f8 89 f6 49 ff c2 4c 89 11 48 c7 44 0a 08 05 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a18c68 EFLAGS: 00000006 RAX: 0000000000010000 RBX: ffffffff89c5f632 RCX: ffff8880256e0000 RDX: ffff8880256e0000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff89c5f662 R09: 1ffffffff284e310 R10: dffffc0000000000 R11: fffffbfff284e311 R12: dffffc0000000000 R13: 1820c40d94000000 R14: ffff88807c470400 R15: ffff88802949d360 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b346e3c20 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:850 [inline] advance_sched+0xa32/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x18/0x90 kernel/kcov.c:314 Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 65 48 8b 14 25 80 d4 03 00 65 8b 05 50 5e 64 7e <25> 00 01 ff 00 74 10 3d 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 RSP: 0018:ffffc9000c557270 EFLAGS: 00000246 RAX: 0000000080000001 RBX: ffffc9000c557868 RCX: ffff8880256e0000 RDX: ffff8880256e0000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc9000c557840 R08: ffffffff81ee1216 R09: 1ffffd400027674e R10: dffffc0000000000 R11: fffff9400027674f R12: dffffc0000000000 R13: 0000000000000001 R14: ffff888055e7d000 R15: 0000000000000000 __tlb_remove_folio_pages_size+0x96/0x590 mm/mmu_gather.c:184 zap_present_folio_ptes mm/memory.c:1531 [inline] zap_present_ptes mm/memory.c:1585 [inline] zap_pte_range mm/memory.c:1627 [inline] zap_pmd_range mm/memory.c:1753 [inline] zap_pud_range mm/memory.c:1782 [inline] zap_p4d_range mm/memory.c:1803 [inline] unmap_page_range+0x1c06/0x4040 mm/memory.c:1824 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1914 exit_mmap+0x275/0xc20 mm/mmap.c:1672 __mmput+0x115/0x3b0 kernel/fork.c:1348 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f32e6585d29 Code: Unable to access opcode bytes at 0x7f32e6585cff. RSP: 002b:00007f32e746f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f32e6776088 RCX: 00007f32e6585d29 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f32e6776088 RBP: 00007f32e6776080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f32e677608c R13: 0000000000000000 R14: 00007fff67c13610 R15: 00007fff67c136f8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g45645 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=43445 rcu: rcu_preempt kthread starved for 10502 jiffies! g45645 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:25976 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244