Extracting prog: 6m6.969463995s
Minimizing prog: 18m35.76067217s
Simplifying prog options: 0s
Extracting C: 3m19.711948395s
Simplifying C: 24m30.796442875s


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}}): syz_usbip_server_init-syz_clone-ptrace
detailed listing:
executing program 0:
syz_usbip_server_init(0x2)
r0 = syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
ptrace(0x10, r0)

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}}): syz_usbip_server_init-syz_clone-ptrace
detailed listing:
executing program 0:
syz_usbip_server_init(0x2)
r0 = syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
ptrace(0x10, r0)

program crashed: kernel panic: hung_task: blocked tasks
single: successfully extracted reproducer
found reproducer with 3 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}}): syz_usbip_server_init-syz_clone
detailed listing:
executing program 0:
syz_usbip_server_init(0x2)
syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 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}}): syz_usbip_server_init-ptrace
detailed listing:
executing program 0:
syz_usbip_server_init(0x2)
ptrace(0x10, 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}}): syz_clone-ptrace
detailed listing:
executing program 0:
r0 = syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
ptrace(0x10, r0)

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}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
simplifying C reproducer
testing compiled C 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}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
testing compiled C 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}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:true Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
detailed listing:
executing program 0:
syz_usbip_server_init(0x2)
r0 = syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
ptrace(0x10, r0)

program crashed: kernel panic: hung_task: blocked tasks
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
detailed listing:
executing program 0:
syz_usbip_server_init(0x2)
r0 = syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
ptrace(0x10, r0)

program crashed: kernel panic: hung_task: blocked tasks
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
detailed listing:
executing program 0:
syz_usbip_server_init(0x2)
r0 = syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
ptrace(0x10, r0)

program crashed: kernel panic: hung_task: blocked tasks
validation run: crashed=true
reproducing took 1h3m30.465480201s
repro crashed as (corrupted=true):
Kernel panic - not syncing: hung_task: blocked tasks
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 vpanic+0x552/0x970 kernel/panic.c:650
 panic+0xd1/0xe0 kernel/panic.c:787
 check_hung_uninterruptible_tasks kernel/hung_task.c:356 [inline]
 watchdog.cold+0x1fd/0x234 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..

report is corrupted, running repro again
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
report is corrupted, running repro again
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
report is corrupted, running repro again
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usbip_server_init-syz_clone-ptrace
program crashed: kernel panic: hung_task: blocked tasks
final repro crashed as (corrupted=true):
Kernel panic - not syncing: hung_task: blocked tasks
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 vpanic+0x552/0x970 kernel/panic.c:650
 panic+0xd1/0xe0 kernel/panic.c:787
 check_hung_uninterruptible_tasks kernel/hung_task.c:356 [inline]
 watchdog.cold+0x1fd/0x234 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Kernel Offset: disabled