Extracting prog: 1m20.984854947s
Minimizing prog: 7m40.327033332s
Simplifying prog options: 2m25.308865139s
Extracting C: 22.482828883s
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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
program crashed: KASAN: use-after-free Write in pppol2tp_release
single: successfully extracted reproducer
found reproducer with 6 syscalls
minimizing guilty program
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040), 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
ioctl$EXT4_IOC_GETFSUUID(0xffffffffffffffff, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
socket$pppl2tp(0x18, 0x1, 0x1)
socket$inet6_udp(0xa, 0x2, 0x0)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r0=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r0, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r1=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r1, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(0xffffffffffffffff, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r0, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r1=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r1, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, 0x0, 0x0)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r1=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r1, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, 0x0, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(0x0, 0x0)
ioctl$EXT4_IOC_GETFSUUID(0xffffffffffffffff, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, 0x0, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(0xffffffffffffffff, 0x40047452, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
a never seen crash title: KASAN: use-after-free Read in pppol2tp_sock_to_session, ignore
simplifying guilty program options
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
a never seen crash title: KASAN: use-after-free Read in pppol2tp_sock_to_session, ignore
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program did not crash
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
extracting C reproducer
testing compiled C program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
a never seen crash title: KASAN: use-after-free Read in pppol2tp_sock_to_session, ignore
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
validation run: crashed=true
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
validation run: crashed=true
testing program (duration=31.170291804s, {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}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-sendfile-syz_clone3-ioctl$EXT4_IOC_GETFSUUID
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000240)=@pppol2tpin6={0x18, 0x1, {0x0, r1, 0x8, 0x0, 0x0, 0x0, {0xa, 0x0, 0x0, @rand_addr=' \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02'}}}, 0x32)
sendfile(0xffffffffffffffff, 0xffffffffffffffff, &(0x7f0000000040)=0x3, 0xac5)
syz_clone3(&(0x7f0000000900)={0x23800000, &(0x7f0000000040)=<r2=>0xffffffffffffffff, 0x0, 0x0, {0x27}, 0x0, 0x0, 0x0, 0x0}, 0x58)
ioctl$EXT4_IOC_GETFSUUID(r2, 0x40047452, 0x0)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
validation run: crashed=true
reproducing took 14m26.850662585s
repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: use-after-free in pppol2tp_sock_to_session+0x1a0/0x1b0 net/l2tp/l2tp_ppp.c:156
Read of size 4 at addr ffff888126ee5000 by task syz.2.17/371

CPU: 0 PID: 371 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 pppol2tp_sock_to_session+0x1a0/0x1b0 net/l2tp/l2tp_ppp.c:156
 pppol2tp_release+0x150/0x2b0 net/l2tp/l2tp_ppp.c:435
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1287
 __fput+0x2dc/0x730 fs/file_table.c:281
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x127/0x190 kernel/task_work.c:189
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xa7c/0x24e0 kernel/exit.c:879
 __do_sys_exit kernel/exit.c:962 [inline]
 __se_sys_exit kernel/exit.c:960 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:960
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f8ad0d470d9
Code: Unable to access opcode bytes at RIP 0x7f8ad0d470af.
RSP: 002b:00007f8ad0ba7ef8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f8ad0d470d9
RDX: 00007f8ad0ba89c8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8ad0dde024 R08: 0000000000000000 R09: 0000000000000058
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ad0fcf038 R14: 00007f8ad0fcefa0 R15: 00007ffff472e888

Allocated by task 370:
 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]
 __kmalloc+0x19f/0x330 mm/slub.c:4038
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 l2tp_session_create+0x39/0xb60 net/l2tp/l2tp_core.c:1616
 pppol2tp_connect+0xbf5/0x1640 net/l2tp/l2tp_ppp.c:772
 __sys_connect_file net/socket.c:1867 [inline]
 __sys_connect+0x3ce/0x450 net/socket.c:1884
 __do_sys_connect net/socket.c:1894 [inline]
 __se_sys_connect net/socket.c:1891 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:1891
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 329:
 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
 l2tp_session_free net/l2tp/l2tp_core.c:168 [inline]
 l2tp_session_put+0xb2/0x1a0 net/l2tp/l2tp_core.c:193
 l2tp_session_delete+0x3a9/0x4a0 net/l2tp/l2tp_core.c:1589
 l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1235 [inline]
 l2tp_tunnel_del_work+0x180/0x3d0 net/l2tp/l2tp_core.c:1273
 process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
 worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
 kthread+0x324/0x3b0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff888126ee5000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 512-byte region [ffff888126ee5000, ffff888126ee5200)
The buggy address belongs to the page:
page:ffffea00049bb900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x126ee4
head:ffffea00049bb900 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043080
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 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 365, ts 26487276653, free_ts 26483836021
 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+0x1f9/0x330 mm/slub.c:4034
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 fib6_info_alloc+0x34/0xe0 net/ipv6/ip6_fib.c:154
 ip6_route_info_create+0x4c7/0x1450 net/ipv6/route.c:3671
 ip6_route_add+0x27/0x130 net/ipv6/route.c:3767
 addrconf_prefix_route net/ipv6/addrconf.c:2469 [inline]
 fixup_permanent_addr net/ipv6/addrconf.c:3525 [inline]
 addrconf_permanent_addr+0x635/0x940 net/ipv6/addrconf.c:3549
 addrconf_notify+0x752/0xea0 net/ipv6/addrconf.c:3617
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410
 call_netdevice_notifiers_info net/core/dev.c:2052 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 __dev_notify_flags+0x2f4/0x5b0 net/core/dev.c:8583
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8621
 do_setlink+0xb19/0x29a0 net/core/rtnetlink.c:2744
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629
 free_the_page mm/page_alloc.c:5445 [inline]
 __free_pages+0xd8/0x390 mm/page_alloc.c:5454
 kfree+0x1e4/0x270 mm/slub.c:4193
 kvfree+0x35/0x40 mm/util.c:647
 ptr_ring_cleanup include/linux/ptr_ring.h:671 [inline]
 wg_packet_queue_free+0x517/0x5a0 drivers/net/wireguard/queueing.c:47
 wg_destruct+0x211/0x300 drivers/net/wireguard/device.c:242
 netdev_run_todo+0xb5e/0xda0 net/core/dev.c:10352
 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112
 default_device_exit_batch+0x363/0x3c0 net/core/dev.c:11299
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x5fe/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
 worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
 kthread+0x324/0x3b0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
 ffff888126ee4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888126ee4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888126ee5000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888126ee5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888126ee5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 371 at net/l2tp/l2tp_ppp.c:156 pppol2tp_sock_to_session+0x167/0x1b0 net/l2tp/l2tp_ppp.c:156
Modules linked in:
CPU: 0 PID: 371 Comm: syz.2.17 Tainted: G    B             syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:pppol2tp_sock_to_session+0x167/0x1b0 net/l2tp/l2tp_ppp.c:156
Code: 5d c3 e8 dc 80 35 fd be 02 00 00 00 eb 0a e8 d0 80 35 fd be 01 00 00 00 4c 89 f7 e8 d3 dc 0e fe e9 0f ff ff ff e8 b9 80 35 fd <0f> 0b 48 89 df e8 ef 00 00 00 eb bd e8 a8 80 35 fd 4c 89 f7 be 03
RSP: 0018:ffffc90002187c40 EFLAGS: 00010293
RAX: ffffffff842f3167 RBX: ffff888110b11800 RCX: ffff88810fe5cf00
RDX: 0000000000000000 RSI: 0000000028ff6120 RDI: 000000000c04eb7d
RBP: ffffc90002187c60 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0dcf848 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000028ff6120 R15: ffff888126ee5000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8ad0d021f0 CR3: 000000010d5e6000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 pppol2tp_release+0x150/0x2b0 net/l2tp/l2tp_ppp.c:435
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1287
 __fput+0x2dc/0x730 fs/file_table.c:281
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x127/0x190 kernel/task_work.c:189
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xa7c/0x24e0 kernel/exit.c:879
 __do_sys_exit kernel/exit.c:962 [inline]
 __se_sys_exit kernel/exit.c:960 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:960
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f8ad0d470d9
Code: Unable to access opcode bytes at RIP 0x7f8ad0d470af.
RSP: 002b:00007f8ad0ba7ef8 EFLAGS: 00000246
 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f8ad0d470d9
RDX: 00007f8ad0ba89c8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8ad0dde024 R08: 0000000000000000 R09: 0000000000000058
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ad0fcf038 R14: 00007f8ad0fcefa0 R15: 00007ffff472e888
---[ end trace 3f9b97bcf14641b1 ]---

final repro crashed as (corrupted=false):
==================================================================
BUG: KASAN: use-after-free in pppol2tp_sock_to_session+0x1a0/0x1b0 net/l2tp/l2tp_ppp.c:156
Read of size 4 at addr ffff888126ee5000 by task syz.2.17/371

CPU: 0 PID: 371 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 pppol2tp_sock_to_session+0x1a0/0x1b0 net/l2tp/l2tp_ppp.c:156
 pppol2tp_release+0x150/0x2b0 net/l2tp/l2tp_ppp.c:435
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1287
 __fput+0x2dc/0x730 fs/file_table.c:281
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x127/0x190 kernel/task_work.c:189
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xa7c/0x24e0 kernel/exit.c:879
 __do_sys_exit kernel/exit.c:962 [inline]
 __se_sys_exit kernel/exit.c:960 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:960
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f8ad0d470d9
Code: Unable to access opcode bytes at RIP 0x7f8ad0d470af.
RSP: 002b:00007f8ad0ba7ef8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f8ad0d470d9
RDX: 00007f8ad0ba89c8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8ad0dde024 R08: 0000000000000000 R09: 0000000000000058
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ad0fcf038 R14: 00007f8ad0fcefa0 R15: 00007ffff472e888

Allocated by task 370:
 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]
 __kmalloc+0x19f/0x330 mm/slub.c:4038
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 l2tp_session_create+0x39/0xb60 net/l2tp/l2tp_core.c:1616
 pppol2tp_connect+0xbf5/0x1640 net/l2tp/l2tp_ppp.c:772
 __sys_connect_file net/socket.c:1867 [inline]
 __sys_connect+0x3ce/0x450 net/socket.c:1884
 __do_sys_connect net/socket.c:1894 [inline]
 __se_sys_connect net/socket.c:1891 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:1891
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 329:
 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
 l2tp_session_free net/l2tp/l2tp_core.c:168 [inline]
 l2tp_session_put+0xb2/0x1a0 net/l2tp/l2tp_core.c:193
 l2tp_session_delete+0x3a9/0x4a0 net/l2tp/l2tp_core.c:1589
 l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1235 [inline]
 l2tp_tunnel_del_work+0x180/0x3d0 net/l2tp/l2tp_core.c:1273
 process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
 worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
 kthread+0x324/0x3b0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff888126ee5000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 512-byte region [ffff888126ee5000, ffff888126ee5200)
The buggy address belongs to the page:
page:ffffea00049bb900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x126ee4
head:ffffea00049bb900 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043080
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 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 365, ts 26487276653, free_ts 26483836021
 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+0x1f9/0x330 mm/slub.c:4034
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 fib6_info_alloc+0x34/0xe0 net/ipv6/ip6_fib.c:154
 ip6_route_info_create+0x4c7/0x1450 net/ipv6/route.c:3671
 ip6_route_add+0x27/0x130 net/ipv6/route.c:3767
 addrconf_prefix_route net/ipv6/addrconf.c:2469 [inline]
 fixup_permanent_addr net/ipv6/addrconf.c:3525 [inline]
 addrconf_permanent_addr+0x635/0x940 net/ipv6/addrconf.c:3549
 addrconf_notify+0x752/0xea0 net/ipv6/addrconf.c:3617
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410
 call_netdevice_notifiers_info net/core/dev.c:2052 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 __dev_notify_flags+0x2f4/0x5b0 net/core/dev.c:8583
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8621
 do_setlink+0xb19/0x29a0 net/core/rtnetlink.c:2744
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629
 free_the_page mm/page_alloc.c:5445 [inline]
 __free_pages+0xd8/0x390 mm/page_alloc.c:5454
 kfree+0x1e4/0x270 mm/slub.c:4193
 kvfree+0x35/0x40 mm/util.c:647
 ptr_ring_cleanup include/linux/ptr_ring.h:671 [inline]
 wg_packet_queue_free+0x517/0x5a0 drivers/net/wireguard/queueing.c:47
 wg_destruct+0x211/0x300 drivers/net/wireguard/device.c:242
 netdev_run_todo+0xb5e/0xda0 net/core/dev.c:10352
 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112
 default_device_exit_batch+0x363/0x3c0 net/core/dev.c:11299
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x5fe/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
 worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
 kthread+0x324/0x3b0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
 ffff888126ee4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888126ee4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888126ee5000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888126ee5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888126ee5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 371 at net/l2tp/l2tp_ppp.c:156 pppol2tp_sock_to_session+0x167/0x1b0 net/l2tp/l2tp_ppp.c:156
Modules linked in:
CPU: 0 PID: 371 Comm: syz.2.17 Tainted: G    B             syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:pppol2tp_sock_to_session+0x167/0x1b0 net/l2tp/l2tp_ppp.c:156
Code: 5d c3 e8 dc 80 35 fd be 02 00 00 00 eb 0a e8 d0 80 35 fd be 01 00 00 00 4c 89 f7 e8 d3 dc 0e fe e9 0f ff ff ff e8 b9 80 35 fd <0f> 0b 48 89 df e8 ef 00 00 00 eb bd e8 a8 80 35 fd 4c 89 f7 be 03
RSP: 0018:ffffc90002187c40 EFLAGS: 00010293
RAX: ffffffff842f3167 RBX: ffff888110b11800 RCX: ffff88810fe5cf00
RDX: 0000000000000000 RSI: 0000000028ff6120 RDI: 000000000c04eb7d
RBP: ffffc90002187c60 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0dcf848 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000028ff6120 R15: ffff888126ee5000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8ad0d021f0 CR3: 000000010d5e6000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 pppol2tp_release+0x150/0x2b0 net/l2tp/l2tp_ppp.c:435
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1287
 __fput+0x2dc/0x730 fs/file_table.c:281
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x127/0x190 kernel/task_work.c:189
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xa7c/0x24e0 kernel/exit.c:879
 __do_sys_exit kernel/exit.c:962 [inline]
 __se_sys_exit kernel/exit.c:960 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:960
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f8ad0d470d9
Code: Unable to access opcode bytes at RIP 0x7f8ad0d470af.
RSP: 002b:00007f8ad0ba7ef8 EFLAGS: 00000246
 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f8ad0d470d9
RDX: 00007f8ad0ba89c8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8ad0dde024 R08: 0000000000000000 R09: 0000000000000058
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ad0fcf038 R14: 00007f8ad0fcefa0 R15: 00007ffff472e888
---[ end trace 3f9b97bcf14641b1 ]---