Extracting prog: 5m48.273562406s Minimizing prog: 55m7.123189259s Simplifying prog options: 13m57.457619929s Extracting C: 2m15.803126628s 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:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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 program crashed: INFO: rcu detected stall in syscall_exit_to_user_mode single: successfully extracted reproducer found reproducer with 4 syscalls minimizing guilty program testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21}, &(0x7f0000000100)) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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:4 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, &(0x7f0000000140)={0xc, 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:4 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, 0x1, &(0x7f0000000080)=0x7) 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:4 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, 0x1, &(0x7f0000000080)=0x7) 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:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, 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:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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:4 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 corrupted a never seen crash title: INFO: rcu detected stall in corrupted, ignore simplifying guilty program options testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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 extracting C reproducer testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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 corrupted a never seen crash title: INFO: rcu detected stall in corrupted, ignore testing program (duration=6m0s, {Threaded:false 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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 1h26m12.193260235s repro crashed as (corrupted=true): rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=10717, q=722 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10493 (4294958955-4294948462), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10493 jiffies! g10717 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:27448 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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: 5973 Comm: syz.0.21 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:131 [inline] RIP: 0010:__raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] RIP: 0010:_raw_spin_lock_irq+0x65/0xf0 kernel/locking/spinlock.c:170 Code: 10 e0 82 8d 8a 49 89 e6 49 c1 ee 03 48 b8 f1 f1 f1 f1 f8 f3 f3 f3 49 bf 00 00 00 00 00 fc ff df 4b 89 04 3e 43 c6 44 3e 04 00 <48> c7 44 24 20 00 00 00 00 9c 8f 44 24 20 8b 44 24 20 43 c6 44 3e RSP: 0018:ffffc900033f7c00 EFLAGS: 00000a02 RAX: f3f3f3f8f1f1f1f1 RBX: ffff8880605d1bc0 RCX: 1ffff1100c0be82e RDX: 1ffff1100c0be8a9 RSI: ffff888028bedf2c RDI: ffff8880605d1bc0 RBP: ffffc900033f7c78 R08: 1ffff1100c0be8a4 R09: 1ffff1100c0be780 R10: dffffc0000000000 R11: ffffed100c0be781 R12: ffff8880605f3c00 R13: ffff888028bede80 R14: 1ffff9200067ef80 R15: dffffc0000000000 FS: 0000555576dd7500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 0000000026f65000 CR4: 00000000003506e0 Call Trace: spin_lock_irq include/linux/spinlock.h:376 [inline] get_signal+0x229/0x1390 kernel/signal.c:2695 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f126e19ce59 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:00007ffd839097f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f126e415fa0 RCX: 00007f126e19ce59 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f126e232e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f126e415fac R14: 00007f126e415fa0 R15: 00007f126e415fa0 report is corrupted, running repro again testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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, &(0x7f0000000140)={0xc, 0x8b}, 0x0) sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7) 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: rcu: (detected by 1, t=10502 jiffies, g=18909, q=927 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10497 (4294975946-4294965449), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10498 jiffies! g18909 f0x2 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:26824 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6412 Comm: syz.7.28 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:131 [inline] RIP: 0010:lock_acquire+0x1ca/0x420 kernel/locking/lockdep.c:5757 Code: c4 28 48 c7 c7 e0 dc ca 8a e8 02 ea 1b 09 b8 ff ff ff ff 65 0f c1 05 bd 85 9a 7e 83 f8 01 0f 85 03 01 00 00 43 c6 44 3c 04 00 <48> c7 84 24 80 00 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 f7 84 RSP: 0018:ffffc90000007b60 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: fe14c710bf66e200 RDX: 0000000000000000 RSI: ffffffff8acadce0 RDI: ffffffff8b1c7be0 RBP: ffffc90000007c80 R08: dffffc0000000000 R09: 1ffffffff22378a0 R10: dffffc0000000000 R11: fffffbfff22378a1 R12: 1ffff92000000f78 R13: ffffffff8d131da0 R14: 0000000000000046 R15: dffffc0000000000 FS: 0000555557391500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 000000005a1b8000 CR4: 00000000003506f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] send_sigqueue+0xb8/0x710 kernel/signal.c:1991 posix_timer_event kernel/time/posix-timers.c:299 [inline] posix_timer_fn+0x14d/0x350 kernel/time/posix-timers.c:325 __run_hrtimer kernel/time/hrtimer.c:1754 [inline] __hrtimer_run_queues+0x525/0xc10 kernel/time/hrtimer.c:1818 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 fa ff da f6 48 89 df e8 a2 d3 db f6 e8 6d ce ff f6 fb bf 01 00 00 00 c2 e3 ce f6 65 8b 05 93 32 76 75 85 c0 74 02 5b c3 e8 60 17 73 RSP: 0018:ffffc900042efc78 EFLAGS: 00000286 RAX: fe14c710bf66e200 RBX: ffff88805f3d4a00 RCX: fe14c710bf66e200 RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff8e8ae5ef R09: 1ffffffff1d15cbd R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: 0000000000000021 R13: ffff88805f3d4e98 R14: dffffc0000000000 R15: 000000001c000004 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1197/0x1390 kernel/signal.c:2906 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f28fb39ce59 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:00007ffd164af6b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f28fb615fa0 RCX: 00007f28fb39ce59 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f28fb432e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f28fb615fac R14: 00007f28fb615fa0 R15: 00007f28fb615fa0