Extracting prog: 5m24.751364228s Minimizing prog: 56m0.373141488s Simplifying prog options: 8m34.196384389s Extracting C: 2m14.769492788s Simplifying C: 0s extracting reproducer from 1 programs testing a last program of every proc single: executing 1 programs separately with timeout 6m0s testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in corrupted single: successfully extracted reproducer found reproducer with 4 syscalls minimizing guilty program testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, 0x0, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, 0x0) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, 0x0, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, 0x0) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, 0x0, 0x0) program did not crash extracting C reproducer testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime program crashed: INFO: rcu detected stall in syscall_exit_to_user_mode a never seen crash title: INFO: rcu detected stall in syscall_exit_to_user_mode, ignore simplifying guilty program options testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in syscall_exit_to_user_mode a never seen crash title: INFO: rcu detected stall in syscall_exit_to_user_mode, ignore testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in corrupted validation run: crashed=true testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in syscall_enter_from_user_mode validation run: crashed=true testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in corrupted validation run: crashed=true reproducing took 1h19m26.821037499s repro crashed as (corrupted=true): rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=5785, q=171) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294958201-4294947699), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g5785 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:27800 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 4357 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:check_preemption_disabled+0x56/0x110 lib/smp_processor_id.c:19 Code: 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 74 cc 65 4c 8b 3d 76 36 46 76 41 f6 RSP: 0018:ffffc90003d8f938 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff888020d78000 RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8a2b3580 RDI: ffffffff8a79f800 RBP: 00000000ffffffff R08: ffff88813fe23207 R09: 1ffff11027fc4640 R10: dffffc0000000000 R11: ffffed1027fc4641 R12: dffffc0000000000 R13: 0000000000000246 R14: ffffffff8c31eb60 R15: 00000000ffffffff FS: 00007f178ad6a6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 000000007b4c7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:431 [inline] lock_is_held_type+0x75/0x190 kernel/locking/lockdep.c:5665 lock_is_held include/linux/lockdep.h:287 [inline] ___might_sleep+0xea/0x610 kernel/sched/core.c:9624 __might_fault+0x6b/0x110 mm/memory.c:5354 __copy_to_user include/linux/uaccess.h:143 [inline] save_xstate_epilog arch/x86/kernel/fpu/signal.c:104 [inline] copy_fpstate_to_sigframe+0x8aa/0xbf0 arch/x86/kernel/fpu/signal.c:217 get_sigframe arch/x86/kernel/signal.c:295 [inline] __setup_rt_frame arch/x86/kernel/signal.c:471 [inline] setup_rt_frame arch/x86/kernel/signal.c:780 [inline] handle_signal arch/x86/kernel/signal.c:824 [inline] arch_do_signal_or_restart+0x679/0x12c0 arch/x86/kernel/signal.c:869 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f178b708797 Code: 83 c8 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 RSP: 002b:00007f178ad6a0e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f178b981fa8 RCX: 00007f178b708799 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f178b981fa8 RBP: 00007f178b981fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f178b982038 R14: 00007ffc3a0ba6e0 R15: 00007ffc3a0ba7c8 report is corrupted, running repro again testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prlimit64(0x0, 0xe, &(0x7f0000000000)={0xa, 0x8b}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000200)=0x4) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in syscall_exit_to_user_mode final repro crashed as (corrupted=false): rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=6809, q=204) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294958246-4294947743), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g6809 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:28016 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 4612 Comm: syz.3.20 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_preemption_disabled+0x6/0x110 lib/smp_processor_id.c:13 Code: e8 32 8a e8 2c 01 00 00 65 ff 0d a1 1b 47 76 5b c3 00 00 cc 48 c7 c7 a0 f7 79 8a 48 c7 c6 e0 f7 79 8a eb 00 55 41 57 41 56 53 <48> 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05 59 RSP: 0018:ffffc90000dd0c38 EFLAGS: 00000086 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815d1900 RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f800 RBP: ffffc90000dd0d68 R08: dffffc0000000000 R09: 1ffffffff203a619 R10: dffffc0000000000 R11: fffffbfff203a61a R12: ffffffff8c331288 R13: 1ffff920001ba198 R14: 0000000000000046 R15: dffffc0000000000 FS: 00007f258c9346c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 00000000226b3000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] lock_acquire+0x1ae/0x400 kernel/locking/lockdep.c:5625 seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:103 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get_update_offsets_now+0x95/0x3e0 kernel/time/timekeeping.c:2303 hrtimer_update_base kernel/time/hrtimer.c:621 [inline] hrtimer_interrupt+0x130/0x8d0 kernel/time/hrtimer.c:1793 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ee ea 97 f7 48 89 df e8 26 c3 98 f7 e8 91 b5 b9 f7 fb bf 01 00 00 00 a6 c9 8c f7 65 8b 05 47 d7 3c 76 85 c0 74 02 5b c3 e8 94 e4 3a RSP: 0018:ffffc9000419fbc0 EFLAGS: 00000282 RAX: ef3aa10679c15e00 RBX: ffff88802bba2500 RCX: ef3aa10679c15e00 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffff88802bba2503 R09: 1ffff110057744a0 R10: dffffc0000000000 R11: ffffed10057744a1 R12: ffff88802bba2500 R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004 spin_unlock_irq include/linux/spinlock.h:414 [inline] get_signal+0x11d6/0x12c0 kernel/signal.c:2903 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f258d2d2797 Code: 83 c8 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 RSP: 002b:00007f258c9340e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f258d54bfa8 RCX: 00007f258d2d2799 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f258d54bfa8 RBP: 00007f258d54bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f258d54c038 R14: 00007ffd94802600 R15: 00007ffd948026e8 sched: RT throttling activated