Extracting prog: 29.639266845s
Minimizing prog: 12m25.384595104s
Simplifying prog options: 0s
Extracting C: 23.040459697s
Simplifying C: 2m57.091645768s


extracting reproducer from 44 programs
first checking the prog from the crash report
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection: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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-bind$inet-ioctl$PPPIOCGL2TPSTATS-openat$tun-socket$nl_generic-syz_genetlink_get_family_id$wireguard-sendmsg$WG_CMD_SET_DEVICE-sendmsg$netlink
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$pppl2tp(0x18, 0x1, 0x1)
r2 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r1)
r3 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r1, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
r4 = socket$inet_udplite(0x2, 0x2, 0x88)
bind$inet(r4, &(0x7f0000000100)={0x2, 0x4e23, @remote}, 0x10)
ioctl$PPPIOCGL2TPSTATS(r3, 0x80487436, 0x0)
openat$tun(0xffffffffffffff9c, &(0x7f0000000040), 0x101000, 0x0)
r5 = socket$nl_generic(0x10, 0x3, 0x10)
r6 = syz_genetlink_get_family_id$wireguard(&(0x7f00000003c0), 0xffffffffffffffff)
sendmsg$WG_CMD_SET_DEVICE(r5, &(0x7f00000000c0)={0x0, 0x0, &(0x7f0000000080)={&(0x7f00000007c0)={0x74, r6, 0x1, 0x0, 0x0, {}, [@WGDEVICE_A_PEERS={0x4c, 0x8, 0x0, 0x1, [{0x48, 0x0, 0x0, 0x1, [@WGPEER_A_ALLOWEDIPS={0x20, 0x9, 0x0, 0x1, [{0x1c, 0x0, 0x0, 0x1, [@ipv4={{0x6, 0x20}, {0x8, 0x2, @remote}, {0x5, 0x3, 0x1}}]}]}, @WGPEER_A_PUBLIC_KEY={0x24, 0x1, @c_g}]}]}, @WGDEVICE_A_IFNAME={0x14, 0x2, 'wg0\x00'}]}, 0x74}, 0x1, 0x0, 0x0, 0x4004840}, 0x40000)
sendmsg$netlink(r0, &(0x7f00000000c0)={0x0, 0x0, &(0x7f0000000080)=[{&(0x7f00000001c0)={0x2c, 0x13, 0x1, 0x2, 0x25dfdbf6, "", [@typed={0x7, 0x0, 0x0, 0x0, @str='\x13\x00\x00'}, @typed={0x8, 0x3fff, 0x0, 0x0, @fd}, @nested={0xc, 0x1a, 0x0, 0x1, [@nested={0x6, 0x0, 0x0, 0x1, [@generic="b057"]}]}]}, 0x2c}], 0x1, 0x0, 0x0, 0xc000}, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
single: successfully extracted reproducer
found reproducer with 15 syscalls
minimizing guilty program
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-bind$inet-ioctl$PPPIOCGL2TPSTATS-openat$tun-socket$nl_generic-syz_genetlink_get_family_id$wireguard-sendmsg$WG_CMD_SET_DEVICE
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
r3 = socket$inet_udplite(0x2, 0x2, 0x88)
bind$inet(r3, &(0x7f0000000100)={0x2, 0x4e23, @remote}, 0x10)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)
openat$tun(0xffffffffffffff9c, &(0x7f0000000040), 0x101000, 0x0)
r4 = socket$nl_generic(0x10, 0x3, 0x10)
r5 = syz_genetlink_get_family_id$wireguard(&(0x7f00000003c0), 0xffffffffffffffff)
sendmsg$WG_CMD_SET_DEVICE(r4, &(0x7f00000000c0)={0x0, 0x0, &(0x7f0000000080)={&(0x7f00000007c0)={0x74, r5, 0x1, 0x0, 0x0, {}, [@WGDEVICE_A_PEERS={0x4c, 0x8, 0x0, 0x1, [{0x48, 0x0, 0x0, 0x1, [@WGPEER_A_ALLOWEDIPS={0x20, 0x9, 0x0, 0x1, [{0x1c, 0x0, 0x0, 0x1, [@ipv4={{0x6, 0x20}, {0x8, 0x2, @remote}, {0x5, 0x3, 0x1}}]}]}, @WGPEER_A_PUBLIC_KEY={0x24, 0x1, @c_g}]}]}, @WGDEVICE_A_IFNAME={0x14, 0x2, 'wg0\x00'}]}, 0x74}, 0x1, 0x0, 0x0, 0x4004840}, 0x40000)

program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-bind$inet-ioctl$PPPIOCGL2TPSTATS-openat$tun-socket$nl_generic-syz_genetlink_get_family_id$wireguard
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
r3 = socket$inet_udplite(0x2, 0x2, 0x88)
bind$inet(r3, &(0x7f0000000100)={0x2, 0x4e23, @remote}, 0x10)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)
openat$tun(0xffffffffffffff9c, &(0x7f0000000040), 0x101000, 0x0)
socket$nl_generic(0x10, 0x3, 0x10)
syz_genetlink_get_family_id$wireguard(&(0x7f00000003c0), 0xffffffffffffffff)

program crashed: KASAN: use-after-free Write in pppol2tp_release
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-bind$inet-ioctl$PPPIOCGL2TPSTATS-openat$tun-socket$nl_generic
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
r3 = socket$inet_udplite(0x2, 0x2, 0x88)
bind$inet(r3, &(0x7f0000000100)={0x2, 0x4e23, @remote}, 0x10)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)
openat$tun(0xffffffffffffff9c, &(0x7f0000000040), 0x101000, 0x0)
socket$nl_generic(0x10, 0x3, 0x10)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-bind$inet-ioctl$PPPIOCGL2TPSTATS-openat$tun
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
r3 = socket$inet_udplite(0x2, 0x2, 0x88)
bind$inet(r3, &(0x7f0000000100)={0x2, 0x4e23, @remote}, 0x10)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)
openat$tun(0xffffffffffffff9c, &(0x7f0000000040), 0x101000, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-bind$inet-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
r3 = socket$inet_udplite(0x2, 0x2, 0x88)
bind$inet(r3, &(0x7f0000000100)={0x2, 0x4e23, @remote}, 0x10)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-bind$inet
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
r2 = socket$inet_udplite(0x2, 0x2, 0x88)
bind$inet(r2, &(0x7f0000000100)={0x2, 0x4e23, @remote}, 0x10)

program did not crash
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-socket$inet_udplite-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
socket$inet_udplite(0x2, 0x2, 0x88)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program did not crash
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(0xffffffffffffffff, 0x80487436, 0x0)

program did not crash
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program did not crash
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-socket$inet6_udp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
socket$inet6_udp(0xa, 0x2, 0x0)
close(r0)
r1 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r1, 0x80487436, 0x0)

program did not crash
testing program (duration=32.209331055s, {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$netlink-socket$pppl2tp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, 0xffffffffffffffff, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r1 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r1, 0x80487436, 0x0)

program did not crash
testing program (duration=32.209331055s, {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$netlink-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(0xffffffffffffffff, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r0, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(0xffffffffffffffff)
r1 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(0xffffffffffffffff, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r1, 0x80487436, 0x0)

program did not crash
testing program (duration=32.209331055s, {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$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
testing program (duration=32.209331055s, {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$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, 0x0, 0x0)
close(r0)
r1 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r1, 0x80487436, 0x0)

program did not crash
testing program (duration=32.209331055s, {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$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, 0x0, 0x0)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=32.209331055s, {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$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
program crashed: KASAN: use-after-free Write in pppol2tp_release
simplifying C reproducer
testing compiled C program (duration=32.209331055s, {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$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
program crashed: KASAN: use-after-free Write in pppol2tp_release
testing compiled C program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
program crashed: KASAN: use-after-free Write in pppol2tp_release
testing compiled C program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
testing compiled C program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
testing compiled C program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
testing compiled C program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
testing program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session
validation run: crashed=true
testing program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
validation run: crashed=true
testing program (duration=32.209331055s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-close-socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev={0xac, 0x14, 0x14, 0x1}}, 0x2}}, 0x2e)
close(r0)
r2 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000140)=@pppol2tpv3in6={0x18, 0x1, {0x0, 0xffffffffffffffff, 0x2, 0x0, 0x6, 0x1, {0xa, 0x4e23, 0x1, @mcast2, 0x9}}}, 0x3a)
ioctl$PPPIOCGL2TPSTATS(r2, 0x80487436, 0x0)

program crashed: KASAN: use-after-free Write in pppol2tp_release
validation run: crashed=true
reproducing took 17m57.363039424s
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 atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline]
BUG: KASAN: use-after-free in atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline]
BUG: KASAN: use-after-free in __mutex_trylock_fast kernel/locking/mutex.c:173 [inline]
BUG: KASAN: use-after-free in mutex_lock+0x85/0xf0 kernel/locking/mutex.c:298
Write of size 8 at addr ffff888111c22950 by task syz.2.17/405

CPU: 1 PID: 405 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x100/0x140 mm/kasan/report.c:452
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline]
 atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline]
 __mutex_trylock_fast kernel/locking/mutex.c:173 [inline]
 mutex_lock+0x85/0xf0 kernel/locking/mutex.c:298
 pppol2tp_release+0x178/0x2b0 net/l2tp/l2tp_ppp.c:442
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1286
 __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
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199
 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f1358657e59
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:00007ffefdb60e18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffefdb60f00 RCX: 00007f1358657e59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000006f30 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b32a20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f13588d0fac R14: 00007f13588d0fa8 R15: 00007f13588d0fa0

Allocated by task 405:
 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:1866 [inline]
 __sys_connect+0x3ce/0x450 net/socket.c:1883
 __do_sys_connect net/socket.c:1893 [inline]
 __se_sys_connect net/socket.c:1890 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:1890
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 405:
 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
 pppol2tp_release+0x169/0x2b0 net/l2tp/l2tp_ppp.c:439
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1286
 __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
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199
 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888111c22800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 336 bytes inside of
 512-byte region [ffff888111c22800, ffff888111c22a00)
The buggy address belongs to the page:
page:ffffea0004470800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111c20
head:ffffea0004470800 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 ffffea00043ef900 0000000400000004 ffff888100043080
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 104, ts 5540872786, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x176/0x190 mm/page_alloc.c:2462
 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541
 __kmalloc_reserve net/core/skbuff.c:144 [inline]
 __alloc_skb+0xdc/0x520 net/core/skbuff.c:212
 alloc_skb include/linux/skbuff.h:1126 [inline]
 alloc_skb_with_frags+0xa3/0x560 net/core/skbuff.c:6006
 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2393
 unix_dgram_sendmsg+0x6f3/0x18f0 net/unix/af_unix.c:1725
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 sock_write_iter+0x2a6/0x3a0 net/socket.c:1018
 call_write_iter include/linux/fs.h:2066 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x770/0xd70 fs/read_write.c:605
 ksys_write+0x14a/0x260 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888111c22800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888111c22880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888111c22900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888111c22980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888111c22a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

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 atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline]
BUG: KASAN: use-after-free in atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline]
BUG: KASAN: use-after-free in __mutex_trylock_fast kernel/locking/mutex.c:173 [inline]
BUG: KASAN: use-after-free in mutex_lock+0x85/0xf0 kernel/locking/mutex.c:298
Write of size 8 at addr ffff888111c22950 by task syz.2.17/405

CPU: 1 PID: 405 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x100/0x140 mm/kasan/report.c:452
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline]
 atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline]
 __mutex_trylock_fast kernel/locking/mutex.c:173 [inline]
 mutex_lock+0x85/0xf0 kernel/locking/mutex.c:298
 pppol2tp_release+0x178/0x2b0 net/l2tp/l2tp_ppp.c:442
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1286
 __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
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199
 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f1358657e59
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:00007ffefdb60e18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffefdb60f00 RCX: 00007f1358657e59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000006f30 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b32a20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f13588d0fac R14: 00007f13588d0fa8 R15: 00007f13588d0fa0

Allocated by task 405:
 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:1866 [inline]
 __sys_connect+0x3ce/0x450 net/socket.c:1883
 __do_sys_connect net/socket.c:1893 [inline]
 __se_sys_connect net/socket.c:1890 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:1890
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 405:
 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
 pppol2tp_release+0x169/0x2b0 net/l2tp/l2tp_ppp.c:439
 __sock_release net/socket.c:597 [inline]
 sock_close+0xb8/0x200 net/socket.c:1286
 __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
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199
 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888111c22800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 336 bytes inside of
 512-byte region [ffff888111c22800, ffff888111c22a00)
The buggy address belongs to the page:
page:ffffea0004470800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111c20
head:ffffea0004470800 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 ffffea00043ef900 0000000400000004 ffff888100043080
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 104, ts 5540872786, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x176/0x190 mm/page_alloc.c:2462
 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541
 __kmalloc_reserve net/core/skbuff.c:144 [inline]
 __alloc_skb+0xdc/0x520 net/core/skbuff.c:212
 alloc_skb include/linux/skbuff.h:1126 [inline]
 alloc_skb_with_frags+0xa3/0x560 net/core/skbuff.c:6006
 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2393
 unix_dgram_sendmsg+0x6f3/0x18f0 net/unix/af_unix.c:1725
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 sock_write_iter+0x2a6/0x3a0 net/socket.c:1018
 call_write_iter include/linux/fs.h:2066 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x770/0xd70 fs/read_write.c:605
 ksys_write+0x14a/0x260 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888111c22800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888111c22880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888111c22900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff888111c22980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888111c22a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================