Extracting prog: 7m54.447839793s Minimizing prog: 1h1m23.567292157s Simplifying prog options: 9m22.692457709s Extracting C: 2m55.485055148s Simplifying C: 0s extracting reproducer from 1 programs testing a last program of every proc single: executing 1 programs separately with timeout 30s testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash program did not crash single: failed to extract reproducer single: executing 1 programs separately with timeout 1m40s testing program (duration=1m40s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash single: failed to extract reproducer single: executing 1 programs separately with timeout 6m0s testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in worker_thread single: successfully extracted reproducer found reproducer with 5 syscalls minimizing guilty program testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) 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:6 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}}): prctl$PR_SCHED_CORE-prlimit64-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(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:6 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}}): prctl$PR_SCHED_CORE-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(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:6 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, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(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:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, 0x0, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(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:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, 0x0) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(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:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) 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:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, 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:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(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:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime program crashed: INFO: rcu detected stall in sys_sendto a never seen crash title: INFO: rcu detected stall in sys_sendto, ignore simplifying guilty program options testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in inet_ioctl a never seen crash title: INFO: rcu detected stall in inet_ioctl, ignore testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in corrupted validation run: crashed=true testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in sys_newfstat validation run: crashed=true testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(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 1h31m57.785989155s repro crashed as (corrupted=true): rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=17925, q=419 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294970632-4294960130), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g17925 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:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 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: 0 UID: 0 PID: 6158 Comm: syz.1.34 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 64 91 63 0c 48 89 de 5b e9 83 71 5f 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 48 f1 79 11 65 8b 15 69 f1 79 RSP: 0018:ffffc900032c7ad8 EFLAGS: 00000246 RAX: ffffffff8168b557 RBX: 0000000000000000 RCX: ffff888034b4bd80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900032c7bf0 R08: ffff888034b4bd87 R09: 1ffff110069697b0 R10: dffffc0000000000 R11: ffffed10069697b1 R12: 0000000000000000 R13: 1ffff110069698ea R14: 00007ff2467fdfd0 R15: dffffc0000000000 FS: 00007ff2467fe6c0(0000) GS:ffff888125225000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 000000002d755000 CR4: 0000000000350ef0 Call Trace: sas_ss_flags include/linux/sched/signal.h:607 [inline] get_sigframe+0x3be/0x820 arch/x86/kernel/signal.c:118 x64_setup_rt_frame+0x160/0xcb0 arch/x86/kernel/signal_64.c:175 setup_rt_frame arch/x86/kernel/signal.c:250 [inline] handle_signal arch/x86/kernel/signal.c:294 [inline] arch_do_signal_or_restart+0x424/0x830 arch/x86/kernel/signal.c:339 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff247062948 Code: ff ff 01 64 48 8b 04 25 00 00 00 00 48 8d b8 d8 fe ff ff e8 4a af 0d 00 85 c0 0f 84 a2 01 00 00 64 f0 83 2c 25 a0 ff ff ff 01 f3 90 0c 00 48 8b 4c 24 08 8b 00 48 83 b9 88 00 00 00 ff 89 81 RSP: 002b:00007ff2467fe050 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007ff247415fa0 RCX: 00007ff247232c91 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff247232c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff247416038 R14: 00007ff247415fa0 R15: 00007fff97218848 report is corrupted, running repro again testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 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}}): prctl$PR_SCHED_CORE-prlimit64-sched_setscheduler-timer_create-timer_settime detailed listing: executing program 0: prctl$PR_SCHED_CORE(0x3e, 0x1, 0x0, 0x0, 0x0) prlimit64(0x0, 0xe, &(0x7f0000000080)={0x8, 0x8d}, 0x0) sched_setscheduler(0x0, 0x2, &(0x7f0000000040)=0x6) timer_create(0x0, &(0x7f0000000680)={0x0, 0x21, 0x0, @tid=0xffffffffffffffff}, &(0x7f0000000100)) timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0) program crashed: INFO: rcu detected stall in worker_thread final repro crashed as (corrupted=false): rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P58/1:b..l rcu: (detected by 1, t=10502 jiffies, g=18881, q=383 ncpus=2) task:kworker/u8:4 state:R running task stack:19904 pid:58 tgid:58 ppid:2 task_flags:0x24248060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893 Code: 06 9e 11 00 00 00 00 eb b5 e8 05 36 14 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 f5 c0 9d 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c5 51 6e ff cc 48 8d 3d 32 a4 94 RSP: 0018:ffffc900015f6740 EFLAGS: 00000282 RAX: d84d0e23c211fb00 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000004 RSI: ffffffff8e247e65 RDI: ffffffff8c2892e0 RBP: ffff88801cb849b0 R08: ffffc900015f7ad0 R09: ffffc900015f6898 R10: dffffc0000000000 R11: fffff520002bed15 R12: 0000000000000004 R13: 0000000000000004 R14: ffffffff8e95cce0 R15: ffff88801cb83d80 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 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 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905 ext4_init_io_end+0x29/0x130 fs/ext4/page-io.c:310 ext4_do_writepages+0xc7e/0x4670 fs/ext4/inode.c:2906 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3042 do_writepages+0x32e/0x550 mm/page-writeback.c:2575 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1762 writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2054 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2130 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2241 wb_check_old_data_flush fs/fs-writeback.c:2345 [inline] wb_do_writeback fs/fs-writeback.c:2398 [inline] wb_workfn+0xb12/0xf10 fs/fs-writeback.c:2426 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 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: rcu_preempt kthread starved for 10568 jiffies! g18881 f0x0 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:27536 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 2b 73 02 e9 fe 1f 5a f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 93 40 13 00 fb f4 d7 1f 5a f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000246 RAX: 00000000000caae7 RBX: ffffffff819a9e9a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dfd1e21 RDI: ffffffff8c2892e0 RBP: ffffc90000197f10 R08: ffff8880b87339db R09: 1ffff110170e673b R10: dffffc0000000000 R11: ffffed10170e673c R12: 0000000000000001 R13: 1ffff11003b56000 R14: 0000000000000001 R15: 1ffff11003b56000 FS: 0000000000000000(0000) GS:ffff888125325000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 0000000074442000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147