rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=13937, q=21) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294968529-4294958027), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g13937 f0x2 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:28568 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9366 Comm: syz-executor.3 Not tainted 5.15.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:110 Code: c7 00 d8 ee 8e e8 f8 87 8b 00 eb b0 66 0f 1f 44 00 00 be 01 00 00 00 e9 16 ef 2d 00 cc cc cc cc cc cc 89 ff 89 b7 00 c0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb 48 RSP: 0018:ffffc90000dc0eb8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff8b339a60 RCX: 0000000000000020 RDX: 1ffffffff166734e RSI: 0000000000000102 RDI: 0000000000000380 RBP: ffff8880b9d1f300 R08: 000000000000003f R09: 0000000000000000 R10: ffffffff8169b477 R11: 0000000000000000 R12: 0000000000000102 R13: 0000000000000020 R14: 0000000000000001 R15: ffff8880b9d223c0 FS: 00007f28d46dc700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f38e3896f22 CR3: 000000001e94b000 CR4: 0000000000350ee0 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x4d/0x80 arch/x86/kernel/apic/apic.c:469 clockevents_program_event+0x254/0x370 kernel/time/clockevents.c:334 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:157 [inline] RIP: 0010:unwind_next_frame+0x216/0x1ce0 arch/x86/kernel/unwind_orc.c:443 Code: 00 00 49 81 ff 68 87 60 89 0f 83 8e 02 00 00 44 8b 1d 6e 12 00 0a 4c 89 fe 48 81 ee 00 00 00 81 48 c1 ee 08 41 8d 43 ff 39 c6 <0f> 83 bc 13 00 00 48 b8 00 00 00 00 00 fc ff df 89 f2 48 8d 3c 95 RSP: 0018:ffffc90003cdf3b0 EFLAGS: 00000297 RAX: 0000000000086088 RBX: 1ffff9200079be7e RCX: 1ffff9200079be9a RDX: dffffc0000000000 RSI: 0000000000084000 RDI: ffff888085196998 RBP: 0000000000000001 R08: ffffffff8b7f83e0 R09: 0000000000000001 R10: fffff5200079be9c R11: 0000000000086089 R12: ffffc90003cdf4d0 R13: ffffc90003cdf4bd R14: ffffc90003cdf488 R15: ffffffff89400067 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1700 [inline] slab_free_freelist_hook+0x81/0x190 mm/slub.c:1725 slab_free mm/slub.c:3483 [inline] kfree+0xe4/0x530 mm/slub.c:4543 tty_free_file drivers/tty/tty_io.c:220 [inline] tty_open+0x7e0/0x1000 drivers/tty/tty_io.c:2149 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x11d0 fs/open.c:822 do_open fs/namei.c:3428 [inline] path_openat+0x1c9a/0x2740 fs/namei.c:3561 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_openat fs/open.c:1232 [inline] __se_sys_openat fs/open.c:1227 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f28d7166a39 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f28d46dc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f28d7269f60 RCX: 00007f28d7166a39 RDX: 0000000000000802 RSI: 0000000020000840 RDI: ffffffffffffff9c RBP: 00007f28d71c0c5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd41e5e0ef R14: 00007f28d46dc300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: c7 00 d8 ee 8e e8 movl $0xe88eeed8,(%rax) 6: f8 clc 7: 87 8b 00 eb b0 66 xchg %ecx,0x66b0eb00(%rbx) d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 12: be 01 00 00 00 mov $0x1,%esi 17: e9 16 ef 2d 00 jmpq 0x2def32 1c: cc int3 1d: cc int3 1e: cc int3 1f: cc int3 20: cc int3 21: cc int3 22: 89 ff mov %edi,%edi 24: 89 b7 00 c0 5f ff mov %esi,-0xa04000(%rdi) * 2a: c3 retq <-- trapping instruction 2b: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 53 push %rbx 3d: 89 fb mov %edi,%ebx 3f: 48 rex.W