Extracting prog: 1m40.923844934s
Minimizing prog: 16m40.641340703s
Simplifying prog options: 0s
Extracting C: 49.453610337s
Simplifying C: 17m6.2796557s


extracting reproducer from 30 programs
first checking the prog from the crash report
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {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}}): mkdirat-mount-write-openat-write-close-socket$inet-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
write(0xffffffffffffffff, &(0x7f0000000180)='udp 2000', 0x8)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)
close(r0)
socket$inet(0x2, 0x2, 0x0)
r1 = openat(0xffffffffffffff9c, &(0x7f0000000400)='./nfsd/threads\x00', 0x2, 0x0)
write(r1, &(0x7f0000000440)='0\n\x00', 0x2)

program crashed: KASAN: use-after-free Write in nfsd_create_serv
single: successfully extracted reproducer
found reproducer with 9 syscalls
minimizing guilty program
testing program (duration=30s, {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}}): mkdirat-mount-write-openat-write-close-socket$inet-openat
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
write(0xffffffffffffffff, &(0x7f0000000180)='udp 2000', 0x8)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)
close(r0)
socket$inet(0x2, 0x2, 0x0)
openat(0xffffffffffffff9c, &(0x7f0000000400)='./nfsd/threads\x00', 0x2, 0x0)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing program (duration=30s, {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}}): mkdirat-mount-write-openat-write-close-socket$inet
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
write(0xffffffffffffffff, &(0x7f0000000180)='udp 2000', 0x8)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)
close(r0)
socket$inet(0x2, 0x2, 0x0)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing program (duration=30s, {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}}): mkdirat-mount-write-openat-write-close
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
write(0xffffffffffffffff, &(0x7f0000000180)='udp 2000', 0x8)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)
close(r0)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing program (duration=30s, {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}}): mkdirat-mount-write-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
write(0xffffffffffffffff, &(0x7f0000000180)='udp 2000', 0x8)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing program (duration=30s, {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}}): mkdirat-mount-write-openat
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
write(0xffffffffffffffff, &(0x7f0000000180)='udp 2000', 0x8)
openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-write-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
write(0xffffffffffffffff, &(0x7f0000000180)='udp 2000', 0x8)
write(0xffffffffffffffff, &(0x7f0000000240)='1\n\x00', 0x2)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing program (duration=30s, {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}}): mkdirat-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program did not crash
testing program (duration=30s, {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}}): mount-openat-write
detailed listing:
executing program 0:
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, 0x0, 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, 0x0, &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', 0x0, 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, 0x0, 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, 0x0, 0x0)

program did not crash
testing program (duration=30s, {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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240), 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=30s, {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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
simplifying C reproducer
testing compiled C program (duration=30s, {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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false 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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false 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}}): mkdirat-mount-openat-write
program did not crash
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:true NetReset:false Cgroups:false 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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false 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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false 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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false 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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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: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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing compiled C program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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}}): mkdirat-mount-openat-write
program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
testing program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
validation run: crashed=true
testing program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
validation run: crashed=true
testing program (duration=30s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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}}): mkdirat-mount-openat-write
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./nfsd\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./nfsd\x00', &(0x7f0000000100)='nfsd\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000200)='./nfsd/threads\x00', 0x2, 0x0)
write(r0, &(0x7f0000000240)='1\n\x00', 0x2)

program crashed: KASAN: use-after-free Write in nfsd_shutdown_threads
validation run: crashed=true
reproducing took 41m4.828800347s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline]
BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: use-after-free in kref_get include/linux/kref.h:45 [inline]
BUG: KASAN: use-after-free in svc_get include/linux/sunrpc/svc.h:108 [inline]
BUG: KASAN: use-after-free in nfsd_shutdown_threads+0x89/0x1a0 fs/nfsd/nfssvc.c:641
Write of size 4 at addr ffff888023eaf450 by task syz-executor/4289

CPU: 1 PID: 4289 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline]
 __refcount_add include/linux/refcount.h:193 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 kref_get include/linux/kref.h:45 [inline]
 svc_get include/linux/sunrpc/svc.h:108 [inline]
 nfsd_shutdown_threads+0x89/0x1a0 fs/nfsd/nfssvc.c:641
 nfsd_umount+0x3e/0xc0 fs/nfsd/nfsctl.c:1411
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:184
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f07e30d1397
Code: a2 c7 05 5c 43 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffdbc020448 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f07e316648b RCX: 00007f07e30d1397
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdbc020500
RBP: 00007ffdbc020500 R08: 00007ffdbc021500 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdbc021590
R13: 00007f07e316648b R14: 00000000000140a7 R15: 00007ffdbc0215d0
 </TASK>

Allocated by task 4339:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 __svc_create+0x60/0x9d0 net/sunrpc/svc.c:485
 svc_create_pooled+0x62f/0x810 net/sunrpc/svc.c:573
 nfsd_create_serv+0x2f9/0x700 fs/nfsd/nfssvc.c:668
 nfsd_svc+0x132/0x9e0 fs/nfsd/nfssvc.c:798
 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:426
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 4339:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 kref_put include/linux/kref.h:65 [inline]
 svc_put include/linux/sunrpc/svc.h:123 [inline]
 nfsd_svc+0x7cf/0x9e0 fs/nfsd/nfssvc.c:821
 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:426
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888023eaf400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 80 bytes inside of
 512-byte region [ffff888023eaf400, ffff888023eaf600)
The buggy address belongs to the page:
page:ffffea00008fab00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23eac
head:ffffea00008fab00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000600000001 ffff888016c41c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2000(__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 11233901261, free_ts 0
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0xf9/0x290 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 usb_cache_string+0x61/0xf0 drivers/usb/core/message.c:1085
 usb_enumerate_device drivers/usb/core/hub.c:2479 [inline]
 usb_new_device+0x26d/0x15d0 drivers/usb/core/hub.c:2607
 register_root_hub+0x258/0x550 drivers/usb/core/hcd.c:1019
 usb_add_hcd+0xbb9/0x1080 drivers/usb/core/hcd.c:3005
 dummy_hcd_probe+0x130/0x260 drivers/usb/gadget/udc/dummy_hcd.c:2704
 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x276/0xc70 drivers/base/dd.c:595
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888023eaf300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888023eaf380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888023eaf400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888023eaf480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023eaf500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

final repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline]
BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: use-after-free in kref_get include/linux/kref.h:45 [inline]
BUG: KASAN: use-after-free in svc_get include/linux/sunrpc/svc.h:108 [inline]
BUG: KASAN: use-after-free in nfsd_shutdown_threads+0x89/0x1a0 fs/nfsd/nfssvc.c:641
Write of size 4 at addr ffff888023eaf450 by task syz-executor/4289

CPU: 1 PID: 4289 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline]
 __refcount_add include/linux/refcount.h:193 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 kref_get include/linux/kref.h:45 [inline]
 svc_get include/linux/sunrpc/svc.h:108 [inline]
 nfsd_shutdown_threads+0x89/0x1a0 fs/nfsd/nfssvc.c:641
 nfsd_umount+0x3e/0xc0 fs/nfsd/nfsctl.c:1411
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:184
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f07e30d1397
Code: a2 c7 05 5c 43 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffdbc020448 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f07e316648b RCX: 00007f07e30d1397
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdbc020500
RBP: 00007ffdbc020500 R08: 00007ffdbc021500 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdbc021590
R13: 00007f07e316648b R14: 00000000000140a7 R15: 00007ffdbc0215d0
 </TASK>

Allocated by task 4339:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 __svc_create+0x60/0x9d0 net/sunrpc/svc.c:485
 svc_create_pooled+0x62f/0x810 net/sunrpc/svc.c:573
 nfsd_create_serv+0x2f9/0x700 fs/nfsd/nfssvc.c:668
 nfsd_svc+0x132/0x9e0 fs/nfsd/nfssvc.c:798
 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:426
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 4339:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 kref_put include/linux/kref.h:65 [inline]
 svc_put include/linux/sunrpc/svc.h:123 [inline]
 nfsd_svc+0x7cf/0x9e0 fs/nfsd/nfssvc.c:821
 write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:426
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888023eaf400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 80 bytes inside of
 512-byte region [ffff888023eaf400, ffff888023eaf600)
The buggy address belongs to the page:
page:ffffea00008fab00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23eac
head:ffffea00008fab00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000600000001 ffff888016c41c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2000(__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 11233901261, free_ts 0
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0xf9/0x290 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 usb_cache_string+0x61/0xf0 drivers/usb/core/message.c:1085
 usb_enumerate_device drivers/usb/core/hub.c:2479 [inline]
 usb_new_device+0x26d/0x15d0 drivers/usb/core/hub.c:2607
 register_root_hub+0x258/0x550 drivers/usb/core/hcd.c:1019
 usb_add_hcd+0xbb9/0x1080 drivers/usb/core/hcd.c:3005
 dummy_hcd_probe+0x130/0x260 drivers/usb/gadget/udc/dummy_hcd.c:2704
 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x276/0xc70 drivers/base/dd.c:595
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888023eaf300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888023eaf380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888023eaf400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888023eaf480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023eaf500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================