Extracting prog: 4m29.109018233s
Minimizing prog: 31m10.754826915s
Simplifying prog options: 8m16.65552709s
Extracting C: 3m41.071865116s
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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program crashed: INFO: rcu detected stall in corrupted
single: successfully extracted reproducer
found reproducer with 2 syscalls
minimizing guilty program
testing program (duration=5m24.574945062s, {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=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program did not crash
testing program (duration=5m24.574945062s, {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 crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, 0x0}, 0x0)

program did not crash
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={0x0}}, 0x0)

program crashed: lost connection to test machine
ignore low priority crash: lost connection to test machine
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0x34, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x4}}]}, 0x34}}, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=5m24.574945062s, {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: task hung in addrconf_dad_work
a never seen crash title: INFO: task hung in addrconf_dad_work, ignore
simplifying guilty program options
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program crashed: INFO: rcu detected stall in x64_sys_call
a never seen crash title: INFO: rcu detected stall in x64_sys_call, ignore
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program did not crash
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program crashed: INFO: rcu detected stall in corrupted
validation run: crashed=true
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program crashed: INFO: rcu detected stall in worker_thread
validation run: crashed=true
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program crashed: INFO: rcu detected stall in corrupted
validation run: crashed=true
reproducing took 57m19.612305661s
repro crashed as (corrupted=true):
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6096/1:b..l
rcu: 	(detected by 1, t=10645 jiffies, g=16541, q=1085 ncpus=2)
task:syz.3.32        state:R  running task     stack:25824 pid:6096  tgid:6096  ppid:5793   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 preempt_schedule_common+0x7f/0xd0 kernel/sched/core.c:7463
 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:201 [inline]
 _raw_spin_unlock+0x41/0x50 kernel/locking/spinlock.c:213
 spin_unlock include/linux/spinlock.h:401 [inline]
 wp_page_copy mm/memory.c:4108 [inline]
 do_wp_page+0x3dca/0x4b80 mm/memory.c:4472
 handle_pte_fault mm/memory.c:6582 [inline]
 __handle_mm_fault mm/memory.c:6707 [inline]
 handle_mm_fault+0x15d7/0x3750 mm/memory.c:6876
 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f7593a5ba1f
RSP: 002b:00007ffe8995b2b0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00007f7593e25fa0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f7593e25fa0
RBP: 00007f7593e25fa0 R08: 00007f7593e25fa0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000000000 R15: 00007f7593e25fa0
 </TASK>
rcu: rcu_preempt kthread starved for 8365 jiffies! g16541 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:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 42 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x80 kernel/kcov.c:212
Code: 8b 3d e4 1f ab 0c 48 89 de 5b e9 23 5e 65 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 78 0f ce 12 65 48 8b 15 78 0f ce 12 f7 c2 00 01 00 ff
RSP: 0018:ffffc90000b26458 EFLAGS: 00000202
RAX: ffffffff81bbcc1e RBX: ffff8880b8443728 RCX: ffff888021af3e80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b265b0 R08: ffff888021af541f R09: 1ffff1100435ea83
R10: dffffc0000000000 R11: ffffffff817a0ad0 R12: 1ffff110170886e5
R13: 0000000000000000 R14: ffff8880b8443720 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888123bbd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b4c834f950 CR3: 0000000072b80000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:363 [inline]
 csd_lock kernel/smp.c:396 [inline]
 smp_call_function_many_cond+0x63e/0x1500 kernel/smp.c:944
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x910/0x10b0 arch/x86/mm/tlb.c:1435
 flush_tlb_page arch/x86/include/asm/tlbflush.h:352 [inline]
 ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:104
 page_vma_mkclean_one+0x4b9/0x840 mm/rmap.c:1146
 page_mkclean_one+0x20c/0x2e0 mm/rmap.c:1194
 __rmap_walk_file+0x4cd/0x6a0 mm/rmap.c:3120
 rmap_walk mm/rmap.c:3164 [inline]
 folio_mkclean+0x2d5/0x3f0 mm/rmap.c:1226
 folio_clear_dirty_for_io+0x190/0x820 mm/page-writeback.c:2903
 mpage_submit_folio+0x83/0x2a0 fs/ext4/inode.c:2075
 mpage_map_and_submit_buffers fs/ext4/inode.c:2331 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2515 [inline]
 ext4_do_writepages+0x203d/0x4770 fs/ext4/inode.c:2938
 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3032
 do_writepages+0x338/0x560 mm/page-writeback.c:2560
 __writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1803
 writeback_sb_inodes+0x9de/0x1b00 fs/fs-writeback.c:2114
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2190
 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2301
 wb_check_old_data_flush fs/fs-writeback.c:2405 [inline]
 wb_do_writeback fs/fs-writeback.c:2484 [inline]
 wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2512
 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
 </TASK>

report is corrupted, running repro again
testing program (duration=5m24.574945062s, {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, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000180)={&(0x7f00000001c0)=@newqdisc={0xa4, 0x24, 0x605, 0x0, 0x0, {0x0, 0x0, 0x0, 0x2a, {0x0, 0x3}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_taprio={{0xb}, {0x74, 0x2, [@TCA_TAPRIO_ATTR_PRIOMAP={0x56, 0x1, {0x1, [], 0x0, [0x1, 0x56, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xfffd], [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3]}}, @TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST={0x10, 0x2, 0x0, 0x1, [{0xc, 0x1, 0x0, 0x1, [@TCA_TAPRIO_SCHED_ENTRY_INTERVAL={0x8, 0x4, 0x1000}]}]}, @TCA_TAPRIO_ATTR_SCHED_CLOCKID={0x8}]}}]}, 0xa4}}, 0x0)

program crashed: INFO: rcu detected stall in worker_thread
final repro crashed as (corrupted=false):
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (3 ticks this GP) idle=2634/1/0x4000000000000000 softirq=19901/19901 fqs=0
rcu: 	(t=13676 jiffies g=15937 q=1269 ncpus=2)
rcu: rcu_preempt kthread starved for 13676 jiffies! g15937 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:27744 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6025 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_power_efficient gc_worker
RIP: 0010:lock_acquire+0x5/0x350 kernel/locking/lockdep.c:5902
Code: 12 a9 00 ff 00 ff 0f 95 c0 c3 cc cc cc cc cc 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 58 4c 89 cb 45 89 c7 41 89 cd
RSP: 0018:ffffc90000a18ce0 EFLAGS: 00000046
RAX: 0000000000000002 RBX: ffffffff89ef9b48 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8fd5c8e0
RBP: ffff888058615800 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006f79656 R12: ffff888058615800
R13: ffff888037bcb000 R14: dffffc0000000000 R15: ffff888037bcb340
FS:  0000000000000000(0000) GS:ffff888123bbd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa3ba5556c8 CR3: 0000000035e14000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 advance_sched+0xa04/0xc80 net/sched/sch_taprio.c:993
 __run_hrtimer kernel/time/hrtimer.c:2074 [inline]
 __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2131
 hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2250
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:348 [inline]
RIP: 0010:gc_worker+0x32a/0x1890 net/netfilter/nf_conntrack_core.c:1532
Code: c7 a0 24 2a 8d be 53 03 00 00 48 c7 c2 e0 24 2a 8d e8 ba 3c a0 f7 e8 b5 3f ff ff 44 8b 35 36 59 77 07 44 89 f6 83 e6 01 31 ff <e8> 21 9e c4 f7 44 89 f0 83 e0 01 75 29 e8 14 99 c4 f7 8b 0d 0a 59
RSP: 0018:ffffc900035ff980 EFLAGS: 00000246
RAX: ffffffff8a02c7eb RBX: 0000000000000001 RCX: ffff88807e821f40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900035ffad0 R08: ffffffff917a367f R09: 1ffffffff22f46cf
R10: dffffc0000000000 R11: fffffbfff22f46d0 R12: dffffc0000000000
R13: ffffffff818fd5aa R14: 0000000000000000 R15: 000000000001136a
 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
 </TASK>
CPU: 0 UID: 0 PID: 5675 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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 87 4e 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 72 49 0c 00 eb 35 f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 58 49 0c 00
RSP: 0000:ffffc9000414f720 EFLAGS: 00000293
RAX: ffffffff81bbd728 RBX: ffff8880b85414c8 RCX: ffff88807e820000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000414f870 R08: ffffffff917a367f R09: 1ffffffff22f46cf
R10: dffffc0000000000 R11: fffffbfff22f46d0 R12: 1ffff110170a8299
R13: dffffc0000000000 R14: 1ffff1100fd042b3 R15: 0000000000000001
FS:  00007fab5724b880(0000) GS:ffff888123abd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f0deedff78 CR3: 0000000074e16000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x910/0x10b0 arch/x86/mm/tlb.c:1435
 flush_tlb_page arch/x86/include/asm/tlbflush.h:352 [inline]
 ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:104
 wp_page_copy mm/memory.c:4073 [inline]
 do_wp_page+0x3c5c/0x4b80 mm/memory.c:4472
 handle_pte_fault mm/memory.c:6582 [inline]
 __handle_mm_fault mm/memory.c:6707 [inline]
 handle_mm_fault+0x15d7/0x3750 mm/memory.c:6876
 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7fab56ab5b69
Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff7968aa50 EFLAGS: 00010206
RAX: 00007fab56bf2020 RBX: 000055f0deedff50 RCX: 000055f0deedff50
RDX: 000055f0deedff50 RSI: 00007fab56bf2020 RDI: 000055f0deedff50
RBP: 00007fab56bf1ac0 R08: 0000000000002760 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000002fb0
R13: 000055f0deee2f00 R14: 0000000000003450 R15: 00007fab56bf1ac0
 </TASK>