Extracting prog: 1m7.845482964s Minimizing prog: 13m50.383980114s Simplifying prog options: 2m37.031875913s Extracting C: 22.012339862s Simplifying C: 0s extracting reproducer from 1 programs testing a last program of every proc single: executing 1 programs separately with timeout 30s testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs: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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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=34.728133792s, {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_put a never seen crash title: KASAN: use-after-free Write in config_item_put, ignore simplifying guilty program options testing program (duration=34.728133792s, {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 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_put a never seen crash title: KASAN: use-after-free Write in config_item_put, ignore testing program (duration=34.728133792s, {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 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 did not crash testing program (duration=34.728133792s, {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 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 did not crash testing program (duration=34.728133792s, {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 validation run: crashed=true testing program (duration=34.728133792s, {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 validation run: crashed=true testing program (duration=34.728133792s, {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 validation run: crashed=true reproducing took 19m44.537299813s repro crashed as (corrupted=false): ================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline] BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline] BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline] BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline] BUG: KASAN: use-after-free in kref_get include/linux/kref.h:45 [inline] BUG: KASAN: use-after-free in config_item_get+0x27/0x90 fs/configfs/item.c:104 Write of size 4 at addr ffff888131b89824 by task syz.3.39/445 CPU: 0 PID: 445 Comm: syz.3.39 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x10f/0x150 mm/kasan/report.c:444 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/linux/atomic/atomic-instrumented.h:111 [inline] __refcount_add include/linux/refcount.h:193 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] config_item_get+0x27/0x90 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+0x44f/0x1330 fs/configfs/symlink.c:191 vfs_symlink+0x29e/0x470 fs/namei.c:4437 do_symlinkat+0x24a/0x5d0 fs/namei.c:4466 __do_sys_symlinkat fs/namei.c:4483 [inline] __se_sys_symlinkat fs/namei.c:4480 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4480 x64_sys_call+0x74b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:267 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f95a1571e99 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:00007f95a13d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f95a17f9fa0 RCX: 00007f95a1571e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007f95a1607eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95a17fa038 R14: 00007f95a17f9fa0 R15: 00007ffc075a94c8 Allocated by task 441: 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:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] kmem_cache_alloc_trace+0x119/0x270 mm/slub.c:3274 kmalloc include/linux/slab.h:619 [inline] kzalloc include/linux/slab.h:750 [inline] fsg_alloc_inst+0x61/0x5a0 drivers/usb/gadget/function/f_mass_storage.c:3392 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:642 configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1329 vfs_mkdir+0x38b/0x590 fs/namei.c:4073 do_mkdirat+0x174/0x4d0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111 x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 436: 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:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kfree+0xc4/0x270 mm/slub.c:4588 fsg_free_inst+0x33c/0x420 drivers/usb/gadget/function/f_mass_storage.c:3383 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:3269 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+0x158/0x210 fs/configfs/item.c:149 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1540 vfs_rmdir+0x1ae/0x450 fs/namei.c:4157 do_rmdir+0x261/0x6b0 fs/namei.c:4218 __do_sys_rmdir fs/namei.c:4237 [inline] __se_sys_rmdir fs/namei.c:4235 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:4235 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:85 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888131b89800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 36 bytes inside of 512-byte region [ffff888131b89800, ffff888131b89a00) The buggy address belongs to the page: page:ffffea0004c6e200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131b88 head:ffffea0004c6e200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100042f00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 365, ts 30023024025, free_ts 29985767809 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa0/0x4d0 mm/slub.c:2000 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954 kmalloc_reserve net/core/skbuff.c:357 [inline] __alloc_skb+0x210/0x730 net/core/skbuff.c:428 alloc_skb include/linux/skbuff.h:1183 [inline] ndisc_alloc_skb net/ipv6/ndisc.c:422 [inline] ndisc_send_rs+0x310/0x960 net/ipv6/ndisc.c:691 addrconf_dad_completed+0x936/0xe20 net/ipv6/addrconf.c:4302 addrconf_dad_work+0xc4c/0x1510 net/ipv6/addrconf.c:-1 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475 kthread+0x3f5/0x4f0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1474 [inline] free_pcp_prepare mm/page_alloc.c:1546 [inline] free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536 free_unref_page+0xae/0x540 mm/page_alloc.c:3618 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5900 free_nonslab_page+0x86/0xc0 mm/slub.c:3564 kfree+0x19a/0x270 mm/slub.c:4585 _fsg_common_free_buffers drivers/usb/gadget/function/f_mass_storage.c:2640 [inline] fsg_common_release drivers/usb/gadget/function/f_mass_storage.c:2927 [inline] fsg_free_inst+0x2c0/0x420 drivers/usb/gadget/function/f_mass_storage.c:3382 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:3269 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+0x158/0x210 fs/configfs/item.c:149 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1540 vfs_rmdir+0x1ae/0x450 fs/namei.c:4157 do_rmdir+0x261/0x6b0 fs/namei.c:4218 __do_sys_rmdir fs/namei.c:4237 [inline] __se_sys_rmdir fs/namei.c:4235 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:4235 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:85 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888131b89700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888131b89780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888131b89800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888131b89880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888131b89900: 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: 0 PID: 445 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 445 Comm: syz.3.39 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 80 47 63 85 e8 c8 47 5a 02 0f 0b eb df e8 5f 80 19 ff c6 05 1b ea 95 04 01 48 c7 c7 c0 46 63 85 e8 ac 47 5a 02 <0f> 0b eb c3 e8 43 80 19 ff c6 05 00 ea 95 04 01 48 c7 c7 20 47 63 RSP: 0018:ffffc90000d27c58 EFLAGS: 00010246 RAX: 893d62a9d511ca00 RBX: 0000000000000002 RCX: ffff8881154293c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000d27c68 R08: ffffc90000d276c7 R09: 1ffff920001a4ed8 R10: dffffc0000000000 R11: fffff520001a4ed9 R12: ffff8881310390a8 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 00007f95a13d36c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005613e7a81748 CR3: 000000013020e000 CR4: 00000000003506b0 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:104 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline] get_target fs/configfs/symlink.c:125 [inline] configfs_symlink+0x44f/0x1330 fs/configfs/symlink.c:191 vfs_symlink+0x29e/0x470 fs/namei.c:4437 do_symlinkat+0x24a/0x5d0 fs/namei.c:4466 __do_sys_symlinkat fs/namei.c:4483 [inline] __se_sys_symlinkat fs/namei.c:4480 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4480 x64_sys_call+0x74b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:267 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f95a1571e99 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:00007f95a13d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f95a17f9fa0 RCX: 00007f95a1571e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007f95a1607eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95a17fa038 R14: 00007f95a17f9fa0 R15: 00007ffc075a94c8 ---[ end trace 74e5b54e71af7955 ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 445 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 1 PID: 445 Comm: syz.3.39 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 c0 46 63 85 e8 ac 47 5a 02 0f 0b eb c3 e8 43 80 19 ff c6 05 00 ea 95 04 01 48 c7 c7 20 47 63 85 e8 90 47 5a 02 <0f> 0b eb a7 e8 27 80 19 ff c6 05 e1 e9 95 04 01 48 c7 c7 60 46 63 RSP: 0018:ffffc90000d27c38 EFLAGS: 00010246 RAX: 893d62a9d511ca00 RBX: 0000000000000003 RCX: ffff8881154293c0 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90000d27c48 R08: ffff8881f7132f3f R09: 1ffff1103ee265e7 R10: dffffc0000000000 R11: ffffed103ee265e8 R12: 00000000ffffffea R13: dffffc0000000000 R14: 0000000000000003 R15: 00000000c0000000 FS: 00007f95a13d36c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5bc1c4580 CR3: 000000013020e000 CR4: 00000000003506a0 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:149 configfs_symlink+0x4a6/0x1330 fs/configfs/symlink.c:212 vfs_symlink+0x29e/0x470 fs/namei.c:4437 do_symlinkat+0x24a/0x5d0 fs/namei.c:4466 __do_sys_symlinkat fs/namei.c:4483 [inline] __se_sys_symlinkat fs/namei.c:4480 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4480 x64_sys_call+0x74b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:267 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f95a1571e99 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:00007f95a13d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f95a17f9fa0 RCX: 00007f95a1571e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007f95a1607eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95a17fa038 R14: 00007f95a17f9fa0 R15: 00007ffc075a94c8 ---[ end trace 74e5b54e71af7957 ]--- final repro crashed as (corrupted=false): ================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:111 [inline] BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline] BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline] BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline] BUG: KASAN: use-after-free in kref_get include/linux/kref.h:45 [inline] BUG: KASAN: use-after-free in config_item_get+0x27/0x90 fs/configfs/item.c:104 Write of size 4 at addr ffff888131b89824 by task syz.3.39/445 CPU: 0 PID: 445 Comm: syz.3.39 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x10f/0x150 mm/kasan/report.c:444 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/linux/atomic/atomic-instrumented.h:111 [inline] __refcount_add include/linux/refcount.h:193 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] config_item_get+0x27/0x90 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+0x44f/0x1330 fs/configfs/symlink.c:191 vfs_symlink+0x29e/0x470 fs/namei.c:4437 do_symlinkat+0x24a/0x5d0 fs/namei.c:4466 __do_sys_symlinkat fs/namei.c:4483 [inline] __se_sys_symlinkat fs/namei.c:4480 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4480 x64_sys_call+0x74b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:267 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f95a1571e99 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:00007f95a13d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f95a17f9fa0 RCX: 00007f95a1571e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007f95a1607eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95a17fa038 R14: 00007f95a17f9fa0 R15: 00007ffc075a94c8 Allocated by task 441: 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:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] kmem_cache_alloc_trace+0x119/0x270 mm/slub.c:3274 kmalloc include/linux/slab.h:619 [inline] kzalloc include/linux/slab.h:750 [inline] fsg_alloc_inst+0x61/0x5a0 drivers/usb/gadget/function/f_mass_storage.c:3392 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:642 configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1329 vfs_mkdir+0x38b/0x590 fs/namei.c:4073 do_mkdirat+0x174/0x4d0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111 x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 436: 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:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kfree+0xc4/0x270 mm/slub.c:4588 fsg_free_inst+0x33c/0x420 drivers/usb/gadget/function/f_mass_storage.c:3383 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:3269 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+0x158/0x210 fs/configfs/item.c:149 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1540 vfs_rmdir+0x1ae/0x450 fs/namei.c:4157 do_rmdir+0x261/0x6b0 fs/namei.c:4218 __do_sys_rmdir fs/namei.c:4237 [inline] __se_sys_rmdir fs/namei.c:4235 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:4235 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:85 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888131b89800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 36 bytes inside of 512-byte region [ffff888131b89800, ffff888131b89a00) The buggy address belongs to the page: page:ffffea0004c6e200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131b88 head:ffffea0004c6e200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100042f00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 365, ts 30023024025, free_ts 29985767809 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa0/0x4d0 mm/slub.c:2000 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954 kmalloc_reserve net/core/skbuff.c:357 [inline] __alloc_skb+0x210/0x730 net/core/skbuff.c:428 alloc_skb include/linux/skbuff.h:1183 [inline] ndisc_alloc_skb net/ipv6/ndisc.c:422 [inline] ndisc_send_rs+0x310/0x960 net/ipv6/ndisc.c:691 addrconf_dad_completed+0x936/0xe20 net/ipv6/addrconf.c:4302 addrconf_dad_work+0xc4c/0x1510 net/ipv6/addrconf.c:-1 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475 kthread+0x3f5/0x4f0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1474 [inline] free_pcp_prepare mm/page_alloc.c:1546 [inline] free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536 free_unref_page+0xae/0x540 mm/page_alloc.c:3618 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5900 free_nonslab_page+0x86/0xc0 mm/slub.c:3564 kfree+0x19a/0x270 mm/slub.c:4585 _fsg_common_free_buffers drivers/usb/gadget/function/f_mass_storage.c:2640 [inline] fsg_common_release drivers/usb/gadget/function/f_mass_storage.c:2927 [inline] fsg_free_inst+0x2c0/0x420 drivers/usb/gadget/function/f_mass_storage.c:3382 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:3269 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+0x158/0x210 fs/configfs/item.c:149 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1540 vfs_rmdir+0x1ae/0x450 fs/namei.c:4157 do_rmdir+0x261/0x6b0 fs/namei.c:4218 __do_sys_rmdir fs/namei.c:4237 [inline] __se_sys_rmdir fs/namei.c:4235 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:4235 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:85 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888131b89700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888131b89780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888131b89800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888131b89880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888131b89900: 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: 0 PID: 445 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 445 Comm: syz.3.39 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 80 47 63 85 e8 c8 47 5a 02 0f 0b eb df e8 5f 80 19 ff c6 05 1b ea 95 04 01 48 c7 c7 c0 46 63 85 e8 ac 47 5a 02 <0f> 0b eb c3 e8 43 80 19 ff c6 05 00 ea 95 04 01 48 c7 c7 20 47 63 RSP: 0018:ffffc90000d27c58 EFLAGS: 00010246 RAX: 893d62a9d511ca00 RBX: 0000000000000002 RCX: ffff8881154293c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000d27c68 R08: ffffc90000d276c7 R09: 1ffff920001a4ed8 R10: dffffc0000000000 R11: fffff520001a4ed9 R12: ffff8881310390a8 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 00007f95a13d36c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005613e7a81748 CR3: 000000013020e000 CR4: 00000000003506b0 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:104 configfs_get_config_item fs/configfs/configfs_internal.h:128 [inline] get_target fs/configfs/symlink.c:125 [inline] configfs_symlink+0x44f/0x1330 fs/configfs/symlink.c:191 vfs_symlink+0x29e/0x470 fs/namei.c:4437 do_symlinkat+0x24a/0x5d0 fs/namei.c:4466 __do_sys_symlinkat fs/namei.c:4483 [inline] __se_sys_symlinkat fs/namei.c:4480 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4480 x64_sys_call+0x74b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:267 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f95a1571e99 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:00007f95a13d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f95a17f9fa0 RCX: 00007f95a1571e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007f95a1607eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95a17fa038 R14: 00007f95a17f9fa0 R15: 00007ffc075a94c8 ---[ end trace 74e5b54e71af7955 ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 445 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 1 PID: 445 Comm: syz.3.39 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 c0 46 63 85 e8 ac 47 5a 02 0f 0b eb c3 e8 43 80 19 ff c6 05 00 ea 95 04 01 48 c7 c7 20 47 63 85 e8 90 47 5a 02 <0f> 0b eb a7 e8 27 80 19 ff c6 05 e1 e9 95 04 01 48 c7 c7 60 46 63 RSP: 0018:ffffc90000d27c38 EFLAGS: 00010246 RAX: 893d62a9d511ca00 RBX: 0000000000000003 RCX: ffff8881154293c0 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90000d27c48 R08: ffff8881f7132f3f R09: 1ffff1103ee265e7 R10: dffffc0000000000 R11: ffffed103ee265e8 R12: 00000000ffffffea R13: dffffc0000000000 R14: 0000000000000003 R15: 00000000c0000000 FS: 00007f95a13d36c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5bc1c4580 CR3: 000000013020e000 CR4: 00000000003506a0 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:149 configfs_symlink+0x4a6/0x1330 fs/configfs/symlink.c:212 vfs_symlink+0x29e/0x470 fs/namei.c:4437 do_symlinkat+0x24a/0x5d0 fs/namei.c:4466 __do_sys_symlinkat fs/namei.c:4483 [inline] __se_sys_symlinkat fs/namei.c:4480 [inline] __x64_sys_symlinkat+0x99/0xb0 fs/namei.c:4480 x64_sys_call+0x74b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:267 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f95a1571e99 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:00007f95a13d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 00007f95a17f9fa0 RCX: 00007f95a1571e99 RDX: 0000200000000300 RSI: ffffffffffffff9c RDI: 0000200000000200 RBP: 00007f95a1607eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95a17fa038 R14: 00007f95a17f9fa0 R15: 00007ffc075a94c8 ---[ end trace 74e5b54e71af7957 ]---