Extracting prog: 1m35.210252453s
Minimizing prog: 15m21.475307778s
Simplifying prog options: 0s
Extracting C: 22.505772279s
Simplifying C: 5m10.501908507s


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:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program crashed: WARNING: refcount bug in config_item_get
single: successfully extracted reproducer
found reproducer with 8 syscalls
minimizing guilty program
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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}}): mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, 0x0, 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, 0x0, &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', 0x0, 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, 0x0, 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, 0x0, 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, 0x0, 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(0x0, 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, 0x0)
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, 0x0, 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program did not crash
testing program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=40.040092681s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program crashed: WARNING: refcount bug in config_item_get
simplifying C reproducer
testing compiled C program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program crashed: WARNING: refcount bug in config_item_get
testing compiled C program (duration=40.040092681s, {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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program did not crash
testing compiled C program (duration=40.040092681s, {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: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-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program did not crash
testing compiled C program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program crashed: WARNING: refcount bug in config_item_get
testing compiled C program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program crashed: WARNING: refcount bug in config_item_get
testing compiled C program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program crashed: WARNING: refcount bug in config_item_get
testing compiled C program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
program crashed: WARNING: refcount bug in config_item_get
testing program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program crashed: WARNING: refcount bug in config_item_get
validation run: crashed=true
testing program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program crashed: WARNING: refcount bug in config_item_get
validation run: crashed=true
testing program (duration=40.040092681s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 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}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000040)='configfs\x00', 0x0, 0x0)
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff)
mkdirat(0xffffffffffffff9c, &(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0x1ff)
symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00')
unlinkat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/configs/c.1/mass_storage.usb0\x00', 0x0)
rmdir(&(0x7f0000000200)='./config/usb_gadget/g1/functions/mass_storage.usb0\x00')

program crashed: WARNING: refcount bug in config_item_get
validation run: crashed=true
reproducing took 24m18.921698338s
repro crashed as (corrupted=false):
Mass Storage Function, version: 2009/09/11
LUN: removable file: (no medium)
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 424 at lib/refcount.c:25 refcount_warn_saturate+0xfd/0x1c0 lib/refcount.c:25
Modules linked in:
CPU: 1 UID: 0 PID: 424 Comm: syz.5.41 Not tainted syzkaller #0 9c722142e1cda5d0ace938c6e5c03d461fe7a5ab
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:refcount_warn_saturate+0xfd/0x1c0 lib/refcount.c:25
Code: 00 00 00 e8 b5 a4 d8 fe 5b 41 5e 5d e9 cc 41 f7 02 cc e8 a6 a4 d8 fe c6 05 a3 77 36 05 01 48 c7 c7 c0 ed 51 86 e8 c3 7c 55 fe <0f> 0b eb da e8 8a a4 d8 fe c6 05 88 77 36 05 01 48 c7 c7 20 ee 51
RSP: 0018:ffffc90000f0fc38 EFLAGS: 00010246
RAX: 18e0efad847d3100 RBX: 0000000000000002 RCX: ffff888113380000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000f0fc48 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e9f34c R12: ffff8881199a6dc8
R13: dffffc0000000000 R14: ffff888119199024 R15: 0000000000000000
FS:  0000555558576500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34a63fff CR3: 0000000119c7c000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:366 [inline]
 refcount_inc include/linux/refcount.h:383 [inline]
 kref_get include/linux/kref.h:45 [inline]
 config_item_get+0x95/0xa0 fs/configfs/item.c:104
 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline]
 get_target fs/configfs/symlink.c:125 [inline]
 configfs_symlink+0x455/0x1050 fs/configfs/symlink.c:191
 vfs_symlink+0x3f7/0x620 fs/namei.c:4623
 do_symlinkat+0x1ba/0x400 fs/namei.c:4649
 __do_sys_symlinkat fs/namei.c:4665 [inline]
 __se_sys_symlinkat fs/namei.c:4662 [inline]
 __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4662
 x64_sys_call+0x1f79/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f32c559de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf5a63778 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f32c5825fa0 RCX: 00007f32c559de99
RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200
RBP: 00007f32c5633eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32c5825fac R14: 00007f32c5825fa0 R15: 00007f32c5825fa0
 </TASK>
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
BUG: KASAN: slab-use-after-free in __refcount_sub_and_test include/linux/refcount.h:389 [inline]
BUG: KASAN: slab-use-after-free in __refcount_dec_and_test include/linux/refcount.h:432 [inline]
BUG: KASAN: slab-use-after-free in refcount_dec_and_test include/linux/refcount.h:450 [inline]
BUG: KASAN: slab-use-after-free in kref_put include/linux/kref.h:64 [inline]
BUG: KASAN: slab-use-after-free in config_item_put+0x37/0x240 fs/configfs/item.c:149
Write of size 4 at addr ffff888119199024 by task syz.5.41/424

CPU: 0 UID: 0 PID: 424 Comm: syz.5.41 Tainted: G        W          syzkaller #0 9c722142e1cda5d0ace938c6e5c03d461fe7a5ab
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 print_address_description+0x71/0x210 mm/kasan/report.c:377
 print_report+0x4a/0x70 mm/kasan/report.c:481
 kasan_report+0x162/0x1a0 mm/kasan/report.c:594
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x25a/0x2b0 mm/kasan/generic.c:189
 __kasan_check_write+0x18/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
 __refcount_sub_and_test include/linux/refcount.h:389 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 kref_put include/linux/kref.h:64 [inline]
 config_item_put+0x37/0x240 fs/configfs/item.c:149
 configfs_symlink+0x4b5/0x1050 fs/configfs/symlink.c:212
 vfs_symlink+0x3f7/0x620 fs/namei.c:4623
 do_symlinkat+0x1ba/0x400 fs/namei.c:4649
 __do_sys_symlinkat fs/namei.c:4665 [inline]
 __se_sys_symlinkat fs/namei.c:4662 [inline]
 __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4662
 x64_sys_call+0x1f79/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f32c559de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf5a63778 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f32c5825fa0 RCX: 00007f32c559de99
RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200
RBP: 00007f32c5633eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32c5825fac R14: 00007f32c5825fa0 R15: 00007f32c5825fa0
 </TASK>

Allocated by task 424:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 poison_kmalloc_redzone mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:261 [inline]
 __kmalloc_cache_noprof+0x23c/0x470 mm/slub.c:4426
 kmalloc_noprof include/linux/slab.h:881 [inline]
 kzalloc_noprof include/linux/slab.h:1017 [inline]
 fsg_alloc_inst+0xe0/0x7f0 drivers/usb/gadget/function/f_mass_storage.c:3500
 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline]
 usb_get_function_instance+0xf7/0x320 drivers/usb/gadget/functions.c:44
 function_make+0x125/0x370 drivers/usb/gadget/configfs.c:631
 configfs_mkdir+0x523/0xb70 fs/configfs/dir.c:1339
 vfs_mkdir+0x58e/0x810 fs/namei.c:4265
 do_mkdirat+0x240/0x530 fs/namei.c:4288
 __do_sys_mkdirat fs/namei.c:4303 [inline]
 __se_sys_mkdirat fs/namei.c:4301 [inline]
 __x64_sys_mkdirat+0x8b/0xa0 fs/namei.c:4301
 x64_sys_call+0x2ba8/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:259
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 421:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_free_info+0x44/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:249 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2445 [inline]
 slab_free mm/slub.c:4714 [inline]
 kfree+0x158/0x440 mm/slub.c:4875
 fsg_free_inst+0x340/0x430 drivers/usb/gadget/function/f_mass_storage.c:3491
 usb_put_function_instance+0xa2/0xc0 drivers/usb/gadget/functions.c:77
 fsg_attr_release+0x19/0x30 drivers/usb/gadget/function/f_mass_storage.c:3377
 config_item_cleanup fs/configfs/item.c:128 [inline]
 config_item_release fs/configfs/item.c:137 [inline]
 kref_put include/linux/kref.h:65 [inline]
 config_item_put+0x175/0x240 fs/configfs/item.c:149
 configfs_rmdir+0x8e8/0x9b0 fs/configfs/dir.c:1550
 vfs_rmdir+0x3db/0x560 fs/namei.c:4348
 do_rmdir+0x29a/0x590 fs/namei.c:4407
 __do_sys_rmdir fs/namei.c:4426 [inline]
 __se_sys_rmdir fs/namei.c:4424 [inline]
 __x64_sys_rmdir+0x4b/0x60 fs/namei.c:4424
 x64_sys_call+0xaf7/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:85
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff888119199000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 36 bytes inside of
 freed 512-byte region [ffff888119199000, ffff888119199200)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x119198
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4000000000000040(head|zone=1)
page_type: f5(slab)
raw: 4000000000000040 ffff888100041c80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 4000000000000040 ffff888100041c80 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 4000000000000002 ffffea0004646601 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 100, tgid 100 (klogd), ts 29780001479, free_ts 29522058757
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1863
 prep_new_page+0x2d/0x180 mm/page_alloc.c:1871
 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3948
 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5315
 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1
 allocate_slab+0x69/0x430 mm/slub.c:2687
 new_slab mm/slub.c:2741 [inline]
 ___slab_alloc+0x591/0x8c0 mm/slub.c:3934
 __slab_alloc mm/slub.c:4025 [inline]
 __slab_alloc_node mm/slub.c:4078 [inline]
 slab_alloc_node mm/slub.c:4239 [inline]
 __do_kmalloc_node mm/slub.c:4394 [inline]
 __kmalloc_node_track_caller_noprof+0x2e3/0x4f0 mm/slub.c:4414
 kmalloc_reserve+0x144/0x4f0 net/core/skbuff.c:618
 __alloc_skb+0x13f/0x360 net/core/skbuff.c:687
 alloc_skb include/linux/skbuff.h:1363 [inline]
 alloc_skb_with_frags+0xd0/0x8b0 net/core/skbuff.c:6617
 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2923
 unix_dgram_sendmsg+0x63a/0x1a90 net/unix/af_unix.c:2040
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x68d/0x700 net/socket.c:2216
 __do_sys_sendto net/socket.c:2228 [inline]
 __se_sys_sendto net/socket.c:2224 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2224
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
page last free pid 381 tgid 381 stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1390 [inline]
 free_unref_page+0xbb8/0xf70 mm/page_alloc.c:2876
 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5402
 __free_slab+0xb2/0x110 mm/slub.c:2758
 free_slab+0x18/0xe0 mm/slub.c:2781
 discard_slab mm/slub.c:2787 [inline]
 __put_partials+0x115/0x150 mm/slub.c:3256
 put_cpu_partial+0x91/0xc0 mm/slub.c:3331
 __slab_free+0x1cf/0x2a0 mm/slub.c:4584
 do_slab_free mm/slub.c:4666 [inline]
 ___cache_free+0xc9/0xe0 mm/slub.c:4781
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0xb5/0x130 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x180 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x28/0x90 mm/kasan/common.c:331
 kasan_slab_alloc include/linux/kasan.h:251 [inline]
 slab_post_alloc_hook mm/slub.c:4202 [inline]
 slab_alloc_node mm/slub.c:4251 [inline]
 kmem_cache_alloc_noprof+0x1bf/0x410 mm/slub.c:4260
 vm_area_dup+0x3f/0x560 kernel/fork.c:501
 dup_mmap kernel/fork.c:683 [inline]
 dup_mm kernel/fork.c:1717 [inline]
 copy_mm+0xb16/0x1da0 kernel/fork.c:1769
 copy_process+0x12a4/0x3350 kernel/fork.c:2429
 kernel_clone+0x233/0x810 kernel/fork.c:2851

Memory state around the buggy address:
 ffff888119198f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888119198f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888119199000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888119199080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888119199100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 424 at lib/refcount.c:28 refcount_warn_saturate+0x119/0x1c0 lib/refcount.c:28
Modules linked in:
CPU: 1 UID: 0 PID: 424 Comm: syz.5.41 Tainted: G    B   W          syzkaller #0 9c722142e1cda5d0ace938c6e5c03d461fe7a5ab
Tainted: [B]=BAD_PAGE, [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:refcount_warn_saturate+0x119/0x1c0 lib/refcount.c:28
Code: 05 01 48 c7 c7 c0 ed 51 86 e8 c3 7c 55 fe 0f 0b eb da e8 8a a4 d8 fe c6 05 88 77 36 05 01 48 c7 c7 20 ee 51 86 e8 a7 7c 55 fe <0f> 0b eb be e8 6e a4 d8 fe c6 05 69 77 36 05 01 48 c7 c7 60 ed 51
RSP: 0018:ffffc90000f0fc18 EFLAGS: 00010246
RAX: 18e0efad847d3100 RBX: 0000000000000003 RCX: ffff888113380000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90000f0fc28 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e9f34c R12: 00000000ffffffea
R13: dffffc0000000000 R14: ffff888119199024 R15: 00000000c0000000
FS:  0000555558576500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34b63fff CR3: 0000000119c7c000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __refcount_sub_and_test include/linux/refcount.h:400 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 kref_put include/linux/kref.h:64 [inline]
 config_item_put+0x230/0x240 fs/configfs/item.c:149
 configfs_symlink+0x4b5/0x1050 fs/configfs/symlink.c:212
 vfs_symlink+0x3f7/0x620 fs/namei.c:4623
 do_symlinkat+0x1ba/0x400 fs/namei.c:4649
 __do_sys_symlinkat fs/namei.c:4665 [inline]
 __se_sys_symlinkat fs/namei.c:4662 [inline]
 __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4662
 x64_sys_call+0x1f79/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f32c559de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf5a63778 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f32c5825fa0 RCX: 00007f32c559de99
RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200
RBP: 00007f32c5633eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32c5825fac R14: 00007f32c5825fa0 R15: 00007f32c5825fa0
 </TASK>
---[ end trace 0000000000000000 ]---

final repro crashed as (corrupted=false):
Mass Storage Function, version: 2009/09/11
LUN: removable file: (no medium)
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 424 at lib/refcount.c:25 refcount_warn_saturate+0xfd/0x1c0 lib/refcount.c:25
Modules linked in:
CPU: 1 UID: 0 PID: 424 Comm: syz.5.41 Not tainted syzkaller #0 9c722142e1cda5d0ace938c6e5c03d461fe7a5ab
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:refcount_warn_saturate+0xfd/0x1c0 lib/refcount.c:25
Code: 00 00 00 e8 b5 a4 d8 fe 5b 41 5e 5d e9 cc 41 f7 02 cc e8 a6 a4 d8 fe c6 05 a3 77 36 05 01 48 c7 c7 c0 ed 51 86 e8 c3 7c 55 fe <0f> 0b eb da e8 8a a4 d8 fe c6 05 88 77 36 05 01 48 c7 c7 20 ee 51
RSP: 0018:ffffc90000f0fc38 EFLAGS: 00010246
RAX: 18e0efad847d3100 RBX: 0000000000000002 RCX: ffff888113380000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000f0fc48 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e9f34c R12: ffff8881199a6dc8
R13: dffffc0000000000 R14: ffff888119199024 R15: 0000000000000000
FS:  0000555558576500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34a63fff CR3: 0000000119c7c000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:366 [inline]
 refcount_inc include/linux/refcount.h:383 [inline]
 kref_get include/linux/kref.h:45 [inline]
 config_item_get+0x95/0xa0 fs/configfs/item.c:104
 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline]
 get_target fs/configfs/symlink.c:125 [inline]
 configfs_symlink+0x455/0x1050 fs/configfs/symlink.c:191
 vfs_symlink+0x3f7/0x620 fs/namei.c:4623
 do_symlinkat+0x1ba/0x400 fs/namei.c:4649
 __do_sys_symlinkat fs/namei.c:4665 [inline]
 __se_sys_symlinkat fs/namei.c:4662 [inline]
 __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4662
 x64_sys_call+0x1f79/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f32c559de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf5a63778 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f32c5825fa0 RCX: 00007f32c559de99
RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200
RBP: 00007f32c5633eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32c5825fac R14: 00007f32c5825fa0 R15: 00007f32c5825fa0
 </TASK>
---[ end trace 0000000000000000 ]---
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
BUG: KASAN: slab-use-after-free in __refcount_sub_and_test include/linux/refcount.h:389 [inline]
BUG: KASAN: slab-use-after-free in __refcount_dec_and_test include/linux/refcount.h:432 [inline]
BUG: KASAN: slab-use-after-free in refcount_dec_and_test include/linux/refcount.h:450 [inline]
BUG: KASAN: slab-use-after-free in kref_put include/linux/kref.h:64 [inline]
BUG: KASAN: slab-use-after-free in config_item_put+0x37/0x240 fs/configfs/item.c:149
Write of size 4 at addr ffff888119199024 by task syz.5.41/424

CPU: 0 UID: 0 PID: 424 Comm: syz.5.41 Tainted: G        W          syzkaller #0 9c722142e1cda5d0ace938c6e5c03d461fe7a5ab
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 print_address_description+0x71/0x210 mm/kasan/report.c:377
 print_report+0x4a/0x70 mm/kasan/report.c:481
 kasan_report+0x162/0x1a0 mm/kasan/report.c:594
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x25a/0x2b0 mm/kasan/generic.c:189
 __kasan_check_write+0x18/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
 __refcount_sub_and_test include/linux/refcount.h:389 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 kref_put include/linux/kref.h:64 [inline]
 config_item_put+0x37/0x240 fs/configfs/item.c:149
 configfs_symlink+0x4b5/0x1050 fs/configfs/symlink.c:212
 vfs_symlink+0x3f7/0x620 fs/namei.c:4623
 do_symlinkat+0x1ba/0x400 fs/namei.c:4649
 __do_sys_symlinkat fs/namei.c:4665 [inline]
 __se_sys_symlinkat fs/namei.c:4662 [inline]
 __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4662
 x64_sys_call+0x1f79/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f32c559de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf5a63778 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f32c5825fa0 RCX: 00007f32c559de99
RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200
RBP: 00007f32c5633eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32c5825fac R14: 00007f32c5825fa0 R15: 00007f32c5825fa0
 </TASK>

Allocated by task 424:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 poison_kmalloc_redzone mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:261 [inline]
 __kmalloc_cache_noprof+0x23c/0x470 mm/slub.c:4426
 kmalloc_noprof include/linux/slab.h:881 [inline]
 kzalloc_noprof include/linux/slab.h:1017 [inline]
 fsg_alloc_inst+0xe0/0x7f0 drivers/usb/gadget/function/f_mass_storage.c:3500
 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline]
 usb_get_function_instance+0xf7/0x320 drivers/usb/gadget/functions.c:44
 function_make+0x125/0x370 drivers/usb/gadget/configfs.c:631
 configfs_mkdir+0x523/0xb70 fs/configfs/dir.c:1339
 vfs_mkdir+0x58e/0x810 fs/namei.c:4265
 do_mkdirat+0x240/0x530 fs/namei.c:4288
 __do_sys_mkdirat fs/namei.c:4303 [inline]
 __se_sys_mkdirat fs/namei.c:4301 [inline]
 __x64_sys_mkdirat+0x8b/0xa0 fs/namei.c:4301
 x64_sys_call+0x2ba8/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:259
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 421:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_free_info+0x44/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:249 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2445 [inline]
 slab_free mm/slub.c:4714 [inline]
 kfree+0x158/0x440 mm/slub.c:4875
 fsg_free_inst+0x340/0x430 drivers/usb/gadget/function/f_mass_storage.c:3491
 usb_put_function_instance+0xa2/0xc0 drivers/usb/gadget/functions.c:77
 fsg_attr_release+0x19/0x30 drivers/usb/gadget/function/f_mass_storage.c:3377
 config_item_cleanup fs/configfs/item.c:128 [inline]
 config_item_release fs/configfs/item.c:137 [inline]
 kref_put include/linux/kref.h:65 [inline]
 config_item_put+0x175/0x240 fs/configfs/item.c:149
 configfs_rmdir+0x8e8/0x9b0 fs/configfs/dir.c:1550
 vfs_rmdir+0x3db/0x560 fs/namei.c:4348
 do_rmdir+0x29a/0x590 fs/namei.c:4407
 __do_sys_rmdir fs/namei.c:4426 [inline]
 __se_sys_rmdir fs/namei.c:4424 [inline]
 __x64_sys_rmdir+0x4b/0x60 fs/namei.c:4424
 x64_sys_call+0xaf7/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:85
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff888119199000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 36 bytes inside of
 freed 512-byte region [ffff888119199000, ffff888119199200)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x119198
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4000000000000040(head|zone=1)
page_type: f5(slab)
raw: 4000000000000040 ffff888100041c80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 4000000000000040 ffff888100041c80 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000
head: 4000000000000002 ffffea0004646601 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 100, tgid 100 (klogd), ts 29780001479, free_ts 29522058757
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1863
 prep_new_page+0x2d/0x180 mm/page_alloc.c:1871
 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3948
 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5315
 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1
 allocate_slab+0x69/0x430 mm/slub.c:2687
 new_slab mm/slub.c:2741 [inline]
 ___slab_alloc+0x591/0x8c0 mm/slub.c:3934
 __slab_alloc mm/slub.c:4025 [inline]
 __slab_alloc_node mm/slub.c:4078 [inline]
 slab_alloc_node mm/slub.c:4239 [inline]
 __do_kmalloc_node mm/slub.c:4394 [inline]
 __kmalloc_node_track_caller_noprof+0x2e3/0x4f0 mm/slub.c:4414
 kmalloc_reserve+0x144/0x4f0 net/core/skbuff.c:618
 __alloc_skb+0x13f/0x360 net/core/skbuff.c:687
 alloc_skb include/linux/skbuff.h:1363 [inline]
 alloc_skb_with_frags+0xd0/0x8b0 net/core/skbuff.c:6617
 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2923
 unix_dgram_sendmsg+0x63a/0x1a90 net/unix/af_unix.c:2040
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x68d/0x700 net/socket.c:2216
 __do_sys_sendto net/socket.c:2228 [inline]
 __se_sys_sendto net/socket.c:2224 [inline]
 __x64_sys_sendto+0xe9/0x100 net/socket.c:2224
 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
page last free pid 381 tgid 381 stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1390 [inline]
 free_unref_page+0xbb8/0xf70 mm/page_alloc.c:2876
 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5402
 __free_slab+0xb2/0x110 mm/slub.c:2758
 free_slab+0x18/0xe0 mm/slub.c:2781
 discard_slab mm/slub.c:2787 [inline]
 __put_partials+0x115/0x150 mm/slub.c:3256
 put_cpu_partial+0x91/0xc0 mm/slub.c:3331
 __slab_free+0x1cf/0x2a0 mm/slub.c:4584
 do_slab_free mm/slub.c:4666 [inline]
 ___cache_free+0xc9/0xe0 mm/slub.c:4781
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0xb5/0x130 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x180 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x28/0x90 mm/kasan/common.c:331
 kasan_slab_alloc include/linux/kasan.h:251 [inline]
 slab_post_alloc_hook mm/slub.c:4202 [inline]
 slab_alloc_node mm/slub.c:4251 [inline]
 kmem_cache_alloc_noprof+0x1bf/0x410 mm/slub.c:4260
 vm_area_dup+0x3f/0x560 kernel/fork.c:501
 dup_mmap kernel/fork.c:683 [inline]
 dup_mm kernel/fork.c:1717 [inline]
 copy_mm+0xb16/0x1da0 kernel/fork.c:1769
 copy_process+0x12a4/0x3350 kernel/fork.c:2429
 kernel_clone+0x233/0x810 kernel/fork.c:2851

Memory state around the buggy address:
 ffff888119198f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888119198f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888119199000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888119199080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888119199100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 424 at lib/refcount.c:28 refcount_warn_saturate+0x119/0x1c0 lib/refcount.c:28
Modules linked in:
CPU: 1 UID: 0 PID: 424 Comm: syz.5.41 Tainted: G    B   W          syzkaller #0 9c722142e1cda5d0ace938c6e5c03d461fe7a5ab
Tainted: [B]=BAD_PAGE, [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:refcount_warn_saturate+0x119/0x1c0 lib/refcount.c:28
Code: 05 01 48 c7 c7 c0 ed 51 86 e8 c3 7c 55 fe 0f 0b eb da e8 8a a4 d8 fe c6 05 88 77 36 05 01 48 c7 c7 20 ee 51 86 e8 a7 7c 55 fe <0f> 0b eb be e8 6e a4 d8 fe c6 05 69 77 36 05 01 48 c7 c7 60 ed 51
RSP: 0018:ffffc90000f0fc18 EFLAGS: 00010246
RAX: 18e0efad847d3100 RBX: 0000000000000003 RCX: ffff888113380000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90000f0fc28 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0e9f34c R12: 00000000ffffffea
R13: dffffc0000000000 R14: ffff888119199024 R15: 00000000c0000000
FS:  0000555558576500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34b63fff CR3: 0000000119c7c000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __refcount_sub_and_test include/linux/refcount.h:400 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 kref_put include/linux/kref.h:64 [inline]
 config_item_put+0x230/0x240 fs/configfs/item.c:149
 configfs_symlink+0x4b5/0x1050 fs/configfs/symlink.c:212
 vfs_symlink+0x3f7/0x620 fs/namei.c:4623
 do_symlinkat+0x1ba/0x400 fs/namei.c:4649
 __do_sys_symlinkat fs/namei.c:4665 [inline]
 __se_sys_symlinkat fs/namei.c:4662 [inline]
 __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4662
 x64_sys_call+0x1f79/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f32c559de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf5a63778 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f32c5825fa0 RCX: 00007f32c559de99
RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200
RBP: 00007f32c5633eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32c5825fac R14: 00007f32c5825fa0 R15: 00007f32c5825fa0
 </TASK>
---[ end trace 0000000000000000 ]---