Extracting prog: 4m34.380522083s Minimizing prog: 37m9.322907175s Simplifying prog options: 7m54.27379128s Extracting C: 2m25.876525977s 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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0xb0, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x80, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffa]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x1c, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0xcd}]}, {0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x81}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8, 0x5, 0x1}]}}]}, 0xb0}}, 0x0) program crashed: INFO: rcu detected stall in x64_sys_call single: successfully extracted reproducer found reproducer with 2 syscalls minimizing guilty program testing program (duration=5m11.29364169s, {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}}): socket$nl_route detailed listing: executing program 0: socket$nl_route(0x10, 0x3, 0x0) program did not crash testing program (duration=5m11.29364169s, {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}}): sendmsg$nl_route_sched detailed listing: executing program 0: sendmsg$nl_route_sched(0xffffffffffffffff, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0xb0, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x80, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffa]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x1c, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0xcd}]}, {0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x81}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8, 0x5, 0x1}]}}]}, 0xb0}}, 0x0) program did not crash testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, 0x0, 0x0) program did not crash testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, 0x0}, 0x0) program did not crash testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={0x0}}, 0x0) program did not crash testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0x34, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x4}}]}, 0x34}}, 0x0) program crashed: lost connection to test machine suppressed program crash: lost connection to test machine extracting C reproducer testing compiled C program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched 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=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0xb0, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x80, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffa]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x1c, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0xcd}]}, {0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x81}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8, 0x5, 0x1}]}}]}, 0xb0}}, 0x0) program crashed: INFO: rcu detected stall in brk a never seen crash title: INFO: rcu detected stall in brk, ignore testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0xb0, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x80, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffa]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x1c, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0xcd}]}, {0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x81}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8, 0x5, 0x1}]}}]}, 0xb0}}, 0x0) VM was preempted during syz execution: failed to run command in VM: instance is preempted, retrying program crashed: INFO: rcu detected stall in sys_clone a never seen crash title: INFO: rcu detected stall in sys_clone, ignore testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0xb0, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x80, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffa]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x1c, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0xcd}]}, {0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x81}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8, 0x5, 0x1}]}}]}, 0xb0}}, 0x0) program crashed: INFO: rcu detected stall in worker_thread validation run: crashed=true testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0xb0, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x80, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffa]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x1c, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0xcd}]}, {0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x81}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8, 0x5, 0x1}]}}]}, 0xb0}}, 0x0) program crashed: INFO: rcu detected stall in vms_gather_munmap_vmas validation run: crashed=true testing program (duration=5m11.29364169s, {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}}): socket$nl_route-sendmsg$nl_route_sched detailed listing: executing program 0: r0 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r0, &(0x7f0000000300)={0x0, 0x0, &(0x7f0000000400)={&(0x7f0000000c40)=@newqdisc={0xb0, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x1}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x80, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffa]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x1c, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0xcd}]}, {0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x81}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8, 0x5, 0x1}]}}]}, 0xb0}}, 0x0) program crashed: INFO: rcu detected stall in x64_sys_call validation run: crashed=true reproducing took 1h0m27.336660582s repro crashed as (corrupted=false): rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=2064/1/0x4000000000000000 softirq=18115/18119 fqs=6 rcu: (detected by 1, t=11263 jiffies, g=17937, q=716 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5779 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__lock_acquire+0x6f2/0x2e50 kernel/locking/lockdep.c:5224 Code: 00 00 18 00 0f 84 b9 00 00 00 4c 89 f6 ba 08 00 00 00 e8 81 47 00 00 31 ed 85 c0 0f 84 93 0d 00 00 83 3d d0 90 fa 18 00 75 13 <48> 63 44 24 10 48 0f a3 05 e1 00 f7 12 0f 83 45 1f 00 00 48 8b 3c RSP: 0018:ffffc90000007bc8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff943b7d18 RDX: 0000000000000008 RSI: ffff888020788bd8 RDI: ffff888020788000 RBP: 0000000000000000 R08: 8c00000000000000 R09: 0000000000080000 R10: 0000000000000000 R11: ffff8880b8628298 R12: ffffffffffffff02 R13: 0000000000000000 R14: ffff888020788bd8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124cd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563ab5a16a38 CR3: 000000000eb48000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:189 __run_hrtimer kernel/time/hrtimer.c:2071 [inline] __hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2124 hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2243 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline] RIP: 0010:__rcu_read_unlock+0x32/0xe0 kernel/rcu/tree_plugin.h:435 Code: 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 39 6e e7 11 48 8d 9f c4 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c <84> c0 75 4f ff 0b 75 1d 4c 8d b7 c8 04 00 00 4c 89 f0 48 c1 e8 03 RSP: 0018:ffffc90002e7f358 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffff8880207884c4 RCX: 0000000000000046 RDX: ffffc90002e7f401 RSI: ffffffff8e6fce08 RDI: ffff888020788000 RBP: 1ffffffff2221b01 R08: ffffc90002e7f510 R09: 0000000000000000 R10: ffffc90002e7f4d8 R11: fffff520005cfe9d R12: 1ffff110040f1098 R13: ffffffff8177f22f R14: ffffc90002e7f488 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:882 [inline] class_rcu_destructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0x1baf/0x2550 arch/x86/kernel/unwind_orc.c:709 __unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6626 anon_vma_chain_free mm/rmap.c:147 [inline] unlink_anon_vmas+0x655/0x720 mm/rmap.c:539 free_pgtables+0x836/0xb70 mm/memory.c:414 exit_mmap+0x4aa/0x9f0 mm/mmap.c:1327 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 __do_sys_exit_group kernel/exit.c:1162 [inline] __se_sys_exit_group kernel/exit.c:1160 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1160 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc075c146c5 Code: Unable to access opcode bytes at 0x7fc075c1469b. RSP: 002b:00007ffc62edc4e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000563ab5a2f040 RCX: 00007fc075c146c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 0000563ab5a0d910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc62edc530 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 11251 jiffies! g17937 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 1107 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:363 [inline] RIP: 0010:smp_call_function_many_cond+0x1132/0x1500 kernel/smp.c:1002 Code: 78 44 8b 2b 44 89 ee 83 e6 01 31 ff e8 47 49 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 32 44 0c 00 eb 35 f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 18 44 0c 00 RSP: 0018:ffffc900052d7720 EFLAGS: 00000293 RAX: ffffffff81bb7708 RBX: ffff8880b8643708 RCX: ffff888028fb5dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900052d7870 R08: ffffffff907a167f R09: 1ffffffff20f42cf R10: dffffc0000000000 R11: fffffbfff20f42d0 R12: 1ffff110170c86e1 R13: dffffc0000000000 R14: 1ffff110051f6e6b R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124dd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563ab5a3fee0 CR3: 000000007c962000 CR4: 00000000003526f0 Call Trace: on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2602 [inline] smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2812 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:902 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 final repro crashed as (corrupted=false): rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=2064/1/0x4000000000000000 softirq=18115/18119 fqs=6 rcu: (detected by 1, t=11263 jiffies, g=17937, q=716 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5779 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__lock_acquire+0x6f2/0x2e50 kernel/locking/lockdep.c:5224 Code: 00 00 18 00 0f 84 b9 00 00 00 4c 89 f6 ba 08 00 00 00 e8 81 47 00 00 31 ed 85 c0 0f 84 93 0d 00 00 83 3d d0 90 fa 18 00 75 13 <48> 63 44 24 10 48 0f a3 05 e1 00 f7 12 0f 83 45 1f 00 00 48 8b 3c RSP: 0018:ffffc90000007bc8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff943b7d18 RDX: 0000000000000008 RSI: ffff888020788bd8 RDI: ffff888020788000 RBP: 0000000000000000 R08: 8c00000000000000 R09: 0000000000080000 R10: 0000000000000000 R11: ffff8880b8628298 R12: ffffffffffffff02 R13: 0000000000000000 R14: ffff888020788bd8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124cd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563ab5a16a38 CR3: 000000000eb48000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:189 __run_hrtimer kernel/time/hrtimer.c:2071 [inline] __hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2124 hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2243 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline] RIP: 0010:__rcu_read_unlock+0x32/0xe0 kernel/rcu/tree_plugin.h:435 Code: 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 39 6e e7 11 48 8d 9f c4 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c <84> c0 75 4f ff 0b 75 1d 4c 8d b7 c8 04 00 00 4c 89 f0 48 c1 e8 03 RSP: 0018:ffffc90002e7f358 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffff8880207884c4 RCX: 0000000000000046 RDX: ffffc90002e7f401 RSI: ffffffff8e6fce08 RDI: ffff888020788000 RBP: 1ffffffff2221b01 R08: ffffc90002e7f510 R09: 0000000000000000 R10: ffffc90002e7f4d8 R11: fffff520005cfe9d R12: 1ffff110040f1098 R13: ffffffff8177f22f R14: ffffc90002e7f488 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:882 [inline] class_rcu_destructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0x1baf/0x2550 arch/x86/kernel/unwind_orc.c:709 __unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6626 anon_vma_chain_free mm/rmap.c:147 [inline] unlink_anon_vmas+0x655/0x720 mm/rmap.c:539 free_pgtables+0x836/0xb70 mm/memory.c:414 exit_mmap+0x4aa/0x9f0 mm/mmap.c:1327 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 __do_sys_exit_group kernel/exit.c:1162 [inline] __se_sys_exit_group kernel/exit.c:1160 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1160 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc075c146c5 Code: Unable to access opcode bytes at 0x7fc075c1469b. RSP: 002b:00007ffc62edc4e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000563ab5a2f040 RCX: 00007fc075c146c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 0000563ab5a0d910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc62edc530 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 11251 jiffies! g17937 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 1107 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:363 [inline] RIP: 0010:smp_call_function_many_cond+0x1132/0x1500 kernel/smp.c:1002 Code: 78 44 8b 2b 44 89 ee 83 e6 01 31 ff e8 47 49 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 32 44 0c 00 eb 35 f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 18 44 0c 00 RSP: 0018:ffffc900052d7720 EFLAGS: 00000293 RAX: ffffffff81bb7708 RBX: ffff8880b8643708 RCX: ffff888028fb5dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900052d7870 R08: ffffffff907a167f R09: 1ffffffff20f42cf R10: dffffc0000000000 R11: fffffbfff20f42d0 R12: 1ffff110170c86e1 R13: dffffc0000000000 R14: 1ffff110051f6e6b R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124dd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563ab5a3fee0 CR3: 000000007c962000 CR4: 00000000003526f0 Call Trace: on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2602 [inline] smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2812 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:902 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245