Extracting prog: 1m13.227364292s Minimizing prog: 12m50.135556473s Simplifying prog options: 0s Extracting C: 29.736053336s Simplifying C: 4m6.902510773s 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: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: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: KASAN: use-after-free Write in config_item_get single: successfully extracted reproducer found reproducer with 8 syscalls minimizing guilty program testing program (duration=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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=36.932393808s, {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: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: KASAN: use-after-free Write in config_item_get simplifying C reproducer testing compiled C program (duration=36.932393808s, {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: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: KASAN: use-after-free Write in config_item_put a never seen crash title: KASAN: use-after-free Write in config_item_put, ignore testing compiled C program (duration=36.932393808s, {Threaded:true 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=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection: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=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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: KASAN: use-after-free Write in config_item_get testing compiled C program (duration=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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: KASAN: use-after-free Write in config_item_put a never seen crash title: KASAN: use-after-free Write in config_item_put, ignore testing compiled C program (duration=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-mkdirat-mkdirat-mkdirat-symlinkat-unlinkat-rmdir program crashed: KASAN: use-after-free Write in config_item_get testing compiled C program (duration=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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:true 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: KASAN: use-after-free Write in config_item_get testing program (duration=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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:true 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: KASAN: use-after-free Write in config_item_get validation run: crashed=true testing program (duration=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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:true 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: KASAN: use-after-free Write in config_item_get validation run: crashed=true testing program (duration=36.932393808s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 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:true 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: KASAN: use-after-free Write in config_item_get validation run: crashed=true reproducing took 20m22.946619786s 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/asm-generic/atomic-instrumented.h:142 [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 config_item_get+0x27/0x90 fs/configfs/item.c:106 Write of size 4 at addr ffff8881179ec024 by task syz.4.71/525 CPU: 1 PID: 525 Comm: syz.4.71 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [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] config_item_get+0x27/0x90 fs/configfs/item.c:106 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline] get_target fs/configfs/symlink.c:127 [inline] configfs_symlink+0x44f/0x1320 fs/configfs/symlink.c:192 vfs_symlink+0x339/0x4c0 fs/namei.c:4107 do_symlinkat+0x10e/0x3d0 fs/namei.c:4134 __do_sys_symlinkat fs/namei.c:4148 [inline] __se_sys_symlinkat fs/namei.c:4145 [inline] __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4145 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7efd548e2e99 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:00007efd54744028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007efd54b6afa0 RCX: 00007efd548e2e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007efd54978eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd54b6b038 R14: 00007efd54b6afa0 R15: 00007fffb55b8f38 Allocated by task 528: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] fsg_alloc_inst+0x61/0x5a0 drivers/usb/gadget/function/f_mass_storage.c:3377 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1354 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 518: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 fsg_free_inst+0x33c/0x420 drivers/usb/gadget/function/f_mass_storage.c:3368 usb_put_function_instance+0x85/0xa0 drivers/usb/gadget/functions.c:77 fsg_attr_release+0x15/0x20 drivers/usb/gadget/function/f_mass_storage.c:3254 config_item_cleanup fs/configfs/item.c:130 [inline] config_item_release fs/configfs/item.c:139 [inline] kref_put include/linux/kref.h:65 [inline] config_item_put+0x158/0x210 fs/configfs/item.c:151 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1580 vfs_rmdir+0x1ab/0x3c0 fs/namei.c:3860 do_rmdir+0x232/0x630 fs/namei.c:3920 __do_sys_rmdir fs/namei.c:3938 [inline] __se_sys_rmdir fs/namei.c:3936 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:3936 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff8881179ec000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 36 bytes inside of 512-byte region [ffff8881179ec000, ffff8881179ec200) The buggy address belongs to the page: page:ffffea00045e7b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881179ed000 pfn:0x1179ec head:ffffea00045e7b00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00044acf00 0000000700000007 ffff888100043080 raw: ffff8881179ed000 000000008010000c 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 100, ts 5365145806, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0xa3/0x560 net/core/skbuff.c:6006 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2393 unix_dgram_sendmsg+0x6f3/0x18f0 net/unix/af_unix.c:1725 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] sock_write_iter+0x2a6/0x3a0 net/socket.c:1019 call_write_iter include/linux/fs.h:2066 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x770/0xd70 fs/read_write.c:605 ksys_write+0x14a/0x260 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 page_owner free stack trace missing Memory state around the buggy address: ffff8881179ebf00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff8881179ebf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881179ec000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881179ec080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881179ec100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 525 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 525 Comm: syz.4.71 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Code: 04 01 48 c7 c7 a0 49 40 85 e8 98 ca 3a 02 0f 0b eb df e8 8f 89 26 ff c6 05 cc 75 82 04 01 48 c7 c7 e0 48 40 85 e8 7c ca 3a 02 <0f> 0b eb c3 e8 73 89 26 ff c6 05 b1 75 82 04 01 48 c7 c7 40 49 40 RSP: 0018:ffffc90002cefc98 EFLAGS: 00010246 RAX: f03f1aab6bd6bc00 RBX: 0000000000000002 RCX: ffff888117eae2c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90002cefca8 R08: ffffc90002cef627 R09: fffff5200059def8 R10: dffffc0000000000 R11: fffff5200059dec5 R12: ffff8881177ff5d0 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 00007efd547446c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002454fb8f2000 CR3: 000000011777d000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [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] config_item_get+0x8c/0x90 fs/configfs/item.c:106 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline] get_target fs/configfs/symlink.c:127 [inline] configfs_symlink+0x44f/0x1320 fs/configfs/symlink.c:192 vfs_symlink+0x339/0x4c0 fs/namei.c:4107 do_symlinkat+0x10e/0x3d0 fs/namei.c:4134 __do_sys_symlinkat fs/namei.c:4148 [inline] __se_sys_symlinkat fs/namei.c:4145 [inline] __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4145 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7efd548e2e99 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:00007efd54744028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007efd54b6afa0 RCX: 00007efd548e2e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007efd54978eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd54b6b038 R14: 00007efd54b6afa0 R15: 00007fffb55b8f38 ---[ end trace 02de03ae4c49fba9 ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 525 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 525 Comm: syz.4.71 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Code: 04 01 48 c7 c7 e0 48 40 85 e8 7c ca 3a 02 0f 0b eb c3 e8 73 89 26 ff c6 05 b1 75 82 04 01 48 c7 c7 40 49 40 85 e8 60 ca 3a 02 <0f> 0b eb a7 e8 57 89 26 ff c6 05 92 75 82 04 01 48 c7 c7 60 48 40 RSP: 0018:ffffc90002cefc78 EFLAGS: 00010246 RAX: f03f1aab6bd6bc00 RBX: 0000000000000003 RCX: ffff888117eae2c0 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90002cefc88 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: 00000000ffffffea R13: dffffc0000000000 R14: 0000000000000003 R15: 00000000c0000000 FS: 00007efd547446c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a55c689250 CR3: 000000011777d000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] kref_put include/linux/kref.h:64 [inline] config_item_put+0x200/0x210 fs/configfs/item.c:151 configfs_symlink+0x4a6/0x1320 fs/configfs/symlink.c:212 vfs_symlink+0x339/0x4c0 fs/namei.c:4107 do_symlinkat+0x10e/0x3d0 fs/namei.c:4134 __do_sys_symlinkat fs/namei.c:4148 [inline] __se_sys_symlinkat fs/namei.c:4145 [inline] __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4145 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7efd548e2e99 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:00007efd54744028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007efd54b6afa0 RCX: 00007efd548e2e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007efd54978eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd54b6b038 R14: 00007efd54b6afa0 R15: 00007fffb55b8f38 ---[ end trace 02de03ae4c49fbab ]--- 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/asm-generic/atomic-instrumented.h:142 [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 config_item_get+0x27/0x90 fs/configfs/item.c:106 Write of size 4 at addr ffff8881179ec024 by task syz.4.71/525 CPU: 1 PID: 525 Comm: syz.4.71 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [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] config_item_get+0x27/0x90 fs/configfs/item.c:106 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline] get_target fs/configfs/symlink.c:127 [inline] configfs_symlink+0x44f/0x1320 fs/configfs/symlink.c:192 vfs_symlink+0x339/0x4c0 fs/namei.c:4107 do_symlinkat+0x10e/0x3d0 fs/namei.c:4134 __do_sys_symlinkat fs/namei.c:4148 [inline] __se_sys_symlinkat fs/namei.c:4145 [inline] __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4145 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7efd548e2e99 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:00007efd54744028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007efd54b6afa0 RCX: 00007efd548e2e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007efd54978eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd54b6b038 R14: 00007efd54b6afa0 R15: 00007fffb55b8f38 Allocated by task 528: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] fsg_alloc_inst+0x61/0x5a0 drivers/usb/gadget/function/f_mass_storage.c:3377 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1354 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 518: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 fsg_free_inst+0x33c/0x420 drivers/usb/gadget/function/f_mass_storage.c:3368 usb_put_function_instance+0x85/0xa0 drivers/usb/gadget/functions.c:77 fsg_attr_release+0x15/0x20 drivers/usb/gadget/function/f_mass_storage.c:3254 config_item_cleanup fs/configfs/item.c:130 [inline] config_item_release fs/configfs/item.c:139 [inline] kref_put include/linux/kref.h:65 [inline] config_item_put+0x158/0x210 fs/configfs/item.c:151 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1580 vfs_rmdir+0x1ab/0x3c0 fs/namei.c:3860 do_rmdir+0x232/0x630 fs/namei.c:3920 __do_sys_rmdir fs/namei.c:3938 [inline] __se_sys_rmdir fs/namei.c:3936 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:3936 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff8881179ec000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 36 bytes inside of 512-byte region [ffff8881179ec000, ffff8881179ec200) The buggy address belongs to the page: page:ffffea00045e7b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881179ed000 pfn:0x1179ec head:ffffea00045e7b00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00044acf00 0000000700000007 ffff888100043080 raw: ffff8881179ed000 000000008010000c 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 100, ts 5365145806, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0xa3/0x560 net/core/skbuff.c:6006 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2393 unix_dgram_sendmsg+0x6f3/0x18f0 net/unix/af_unix.c:1725 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] sock_write_iter+0x2a6/0x3a0 net/socket.c:1019 call_write_iter include/linux/fs.h:2066 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x770/0xd70 fs/read_write.c:605 ksys_write+0x14a/0x260 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 page_owner free stack trace missing Memory state around the buggy address: ffff8881179ebf00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff8881179ebf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881179ec000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881179ec080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881179ec100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 525 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 525 Comm: syz.4.71 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Code: 04 01 48 c7 c7 a0 49 40 85 e8 98 ca 3a 02 0f 0b eb df e8 8f 89 26 ff c6 05 cc 75 82 04 01 48 c7 c7 e0 48 40 85 e8 7c ca 3a 02 <0f> 0b eb c3 e8 73 89 26 ff c6 05 b1 75 82 04 01 48 c7 c7 40 49 40 RSP: 0018:ffffc90002cefc98 EFLAGS: 00010246 RAX: f03f1aab6bd6bc00 RBX: 0000000000000002 RCX: ffff888117eae2c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90002cefca8 R08: ffffc90002cef627 R09: fffff5200059def8 R10: dffffc0000000000 R11: fffff5200059dec5 R12: ffff8881177ff5d0 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 00007efd547446c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002454fb8f2000 CR3: 000000011777d000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [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] config_item_get+0x8c/0x90 fs/configfs/item.c:106 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline] get_target fs/configfs/symlink.c:127 [inline] configfs_symlink+0x44f/0x1320 fs/configfs/symlink.c:192 vfs_symlink+0x339/0x4c0 fs/namei.c:4107 do_symlinkat+0x10e/0x3d0 fs/namei.c:4134 __do_sys_symlinkat fs/namei.c:4148 [inline] __se_sys_symlinkat fs/namei.c:4145 [inline] __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4145 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7efd548e2e99 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:00007efd54744028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007efd54b6afa0 RCX: 00007efd548e2e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007efd54978eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd54b6b038 R14: 00007efd54b6afa0 R15: 00007fffb55b8f38 ---[ end trace 02de03ae4c49fba9 ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 525 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 525 Comm: syz.4.71 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Code: 04 01 48 c7 c7 e0 48 40 85 e8 7c ca 3a 02 0f 0b eb c3 e8 73 89 26 ff c6 05 b1 75 82 04 01 48 c7 c7 40 49 40 85 e8 60 ca 3a 02 <0f> 0b eb a7 e8 57 89 26 ff c6 05 92 75 82 04 01 48 c7 c7 60 48 40 RSP: 0018:ffffc90002cefc78 EFLAGS: 00010246 RAX: f03f1aab6bd6bc00 RBX: 0000000000000003 RCX: ffff888117eae2c0 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90002cefc88 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: 00000000ffffffea R13: dffffc0000000000 R14: 0000000000000003 R15: 00000000c0000000 FS: 00007efd547446c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a55c689250 CR3: 000000011777d000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] kref_put include/linux/kref.h:64 [inline] config_item_put+0x200/0x210 fs/configfs/item.c:151 configfs_symlink+0x4a6/0x1320 fs/configfs/symlink.c:212 vfs_symlink+0x339/0x4c0 fs/namei.c:4107 do_symlinkat+0x10e/0x3d0 fs/namei.c:4134 __do_sys_symlinkat fs/namei.c:4148 [inline] __se_sys_symlinkat fs/namei.c:4145 [inline] __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4145 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7efd548e2e99 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:00007efd54744028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007efd54b6afa0 RCX: 00007efd548e2e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007efd54978eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd54b6b038 R14: 00007efd54b6afa0 R15: 00007fffb55b8f38 ---[ end trace 02de03ae4c49fbab ]---