Extracting prog: 1m4.036009755s Minimizing prog: 10m48.490210794s Simplifying prog options: 0s Extracting C: 40.585184303s Simplifying C: 2m42.94447274s extracting reproducer from 51 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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX-syz_genetlink_get_family_id$nl80211-ioctl$sock_SIOCGIFINDEX_80211-ioctl$sock_SIOCGIFINDEX_80211-sendmsg$NL80211_CMD_SET_STATION-connect$pppl2tp-close_range detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) r3 = socket$inet6_udp(0xa, 0x2, 0x0) r4 = socket$pppl2tp(0x18, 0x1, 0x1) r5 = socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX(r5, 0x8933, &(0x7f0000000340)={'gre0\x00'}) r6 = syz_genetlink_get_family_id$nl80211(&(0x7f00000000c0), 0xffffffffffffffff) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00', 0x0}) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000180)={'wlan1\x00', 0x0}) sendmsg$NL80211_CMD_SET_STATION(r5, &(0x7f0000000240)={&(0x7f0000000080), 0xc, &(0x7f0000000200)={&(0x7f00000001c0)={0x2c, r6, 0x100, 0x70bd25, 0x25dfdbfc, {{}, {@val={0x8, 0x3, r7}, @void}}, [@NL80211_ATTR_STA_TX_POWER_SETTING={0x5}, @NL80211_ATTR_STA_VLAN={0x8, 0x14, r8}]}, 0x2c}, 0x1, 0x0, 0x0, 0x24000004}, 0x4) connect$pppl2tp(r4, &(0x7f0000000100)=@pppol2tpv3={0x18, 0x1, {0x0, r3, {0x2, 0x0, @loopback}, 0x80004, 0x0, 0xffffffff}}, 0x2e) close_range(r0, 0xffffffffffffffff, 0x200000000000000) program crashed: KASAN: use-after-free Read in l2tp_session_register single: successfully extracted reproducer found reproducer with 15 syscalls minimizing guilty program testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX-syz_genetlink_get_family_id$nl80211-ioctl$sock_SIOCGIFINDEX_80211-ioctl$sock_SIOCGIFINDEX_80211-sendmsg$NL80211_CMD_SET_STATION-connect$pppl2tp detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) r3 = socket$inet6_udp(0xa, 0x2, 0x0) r4 = socket$pppl2tp(0x18, 0x1, 0x1) r5 = socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX(r5, 0x8933, &(0x7f0000000340)={'gre0\x00'}) r6 = syz_genetlink_get_family_id$nl80211(&(0x7f00000000c0), 0xffffffffffffffff) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00', 0x0}) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000180)={'wlan1\x00', 0x0}) sendmsg$NL80211_CMD_SET_STATION(r5, &(0x7f0000000240)={&(0x7f0000000080), 0xc, &(0x7f0000000200)={&(0x7f00000001c0)={0x2c, r6, 0x100, 0x70bd25, 0x25dfdbfc, {{}, {@val={0x8, 0x3, r7}, @void}}, [@NL80211_ATTR_STA_TX_POWER_SETTING={0x5}, @NL80211_ATTR_STA_VLAN={0x8, 0x14, r8}]}, 0x2c}, 0x1, 0x0, 0x0, 0x24000004}, 0x4) connect$pppl2tp(r4, &(0x7f0000000100)=@pppol2tpv3={0x18, 0x1, {0x0, r3, {0x2, 0x0, @loopback}, 0x80004, 0x0, 0xffffffff}}, 0x2e) program crashed: KASAN: use-after-free Read in l2tp_session_register testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX-syz_genetlink_get_family_id$nl80211-ioctl$sock_SIOCGIFINDEX_80211-ioctl$sock_SIOCGIFINDEX_80211-sendmsg$NL80211_CMD_SET_STATION detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) socket$pppl2tp(0x18, 0x1, 0x1) r3 = socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX(r3, 0x8933, &(0x7f0000000340)={'gre0\x00'}) r4 = syz_genetlink_get_family_id$nl80211(&(0x7f00000000c0), 0xffffffffffffffff) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00', 0x0}) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000180)={'wlan1\x00', 0x0}) sendmsg$NL80211_CMD_SET_STATION(r3, &(0x7f0000000240)={&(0x7f0000000080), 0xc, &(0x7f0000000200)={&(0x7f00000001c0)={0x2c, r4, 0x100, 0x70bd25, 0x25dfdbfc, {{}, {@val={0x8, 0x3, r5}, @void}}, [@NL80211_ATTR_STA_TX_POWER_SETTING={0x5}, @NL80211_ATTR_STA_VLAN={0x8, 0x14, r6}]}, 0x2c}, 0x1, 0x0, 0x0, 0x24000004}, 0x4) program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX-syz_genetlink_get_family_id$nl80211-ioctl$sock_SIOCGIFINDEX_80211-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) socket$pppl2tp(0x18, 0x1, 0x1) r3 = socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX(r3, 0x8933, &(0x7f0000000340)={'gre0\x00'}) syz_genetlink_get_family_id$nl80211(&(0x7f00000000c0), 0xffffffffffffffff) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000180)={'wlan1\x00'}) program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX-syz_genetlink_get_family_id$nl80211-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) socket$pppl2tp(0x18, 0x1, 0x1) r3 = socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX(r3, 0x8933, &(0x7f0000000340)={'gre0\x00'}) syz_genetlink_get_family_id$nl80211(&(0x7f00000000c0), 0xffffffffffffffff) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX-syz_genetlink_get_family_id$nl80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) socket$pppl2tp(0x18, 0x1, 0x1) r3 = socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX(r3, 0x8933, &(0x7f0000000340)={'gre0\x00'}) syz_genetlink_get_family_id$nl80211(&(0x7f00000000c0), 0xffffffffffffffff) program did not crash testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) socket$pppl2tp(0x18, 0x1, 0x1) r3 = socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX(r3, 0x8933, &(0x7f0000000340)={'gre0\x00'}) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-socket$nl_generic-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) socket$pppl2tp(0x18, 0x1, 0x1) socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-socket$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) socket$pppl2tp(0x18, 0x1, 0x1) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-socket$inet6_udp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) socket$inet6_udp(0xa, 0x2, 0x0) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-connect$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) r2 = socket$inet6_udp(0xa, 0x2, 0x0) close(r0) connect$pppl2tp(r1, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r2, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-close-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r1 = socket$pppl2tp(0x18, 0x1, 0x1) socket$inet6_udp(0xa, 0x2, 0x0) close(r0) ioctl$sock_SIOCGIFINDEX_80211(r1, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program did not crash testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Write in rcu_segcblist_enqueue testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$pppl2tp-connect$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r0 = socket$pppl2tp(0x18, 0x1, 0x1) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, 0xffffffffffffffff, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program did not crash testing program (duration=32.051096847s, {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}}): seccomp$SECCOMP_SET_MODE_FILTER_LISTENER-socket$inet6_udp-connect$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: seccomp$SECCOMP_SET_MODE_FILTER_LISTENER(0x1, 0x0, &(0x7f0000000040)={0x1, &(0x7f0000000000)=[{0x6, 0x0, 0x2, 0x7fff7ffc}]}) r0 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(0xffffffffffffffff, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r0, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(0xffffffffffffffff, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program did not crash testing program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, 0x0, 0x0) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, &(0x7f0000000140)={'wlan1\x00'}) program did not crash testing program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, 0x0) program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session extracting C reproducer testing compiled C program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 program crashed: KASAN: use-after-free Write in pppol2tp_release simplifying C reproducer testing compiled C program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing compiled C program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing compiled C program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release validation run: crashed=true testing program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release validation run: crashed=true testing program (duration=32.051096847s, {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$pppl2tp-ioctl$sock_SIOCGIFINDEX_80211 detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$sock_SIOCGIFINDEX_80211(r0, 0x8933, 0x0) program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session validation run: crashed=true reproducing took 16m39.639307579s 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 ffff888111449800 by task syz.2.17/392 CPU: 0 PID: 392 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 __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: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: 0033:0x7f6b2965ae59 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:00007ffd64b4aa78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffd64b4ab60 RCX: 00007f6b2965ae59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 0000000000006ee9 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b32c20000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6b298d3fac R14: 00007f6b298d3fa8 R15: 00007f6b298d3fa0 Allocated by task 392: 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 333: 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 ffff888111449800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff888111449800, ffff888111449a00) The buggy address belongs to the page: page:ffffea0004451200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111448 head:ffffea0004451200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 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 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 365, ts 28406685763, free_ts 28386269459 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:3672 ip6_route_add+0x27/0x130 net/ipv6/route.c:3768 addrconf_prefix_route net/ipv6/addrconf.c:2463 [inline] fixup_permanent_addr net/ipv6/addrconf.c:3519 [inline] addrconf_permanent_addr+0x635/0x940 net/ipv6/addrconf.c:3543 addrconf_notify+0x752/0xea0 net/ipv6/addrconf.c:3611 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:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers net/core/dev.c:2080 [inline] __dev_notify_flags+0x2f4/0x5b0 net/core/dev.c:8585 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8623 do_setlink+0xb19/0x29a0 net/core/rtnetlink.c:2736 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 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x150/0x180 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x15a/0x2d0 mm/slub.c:2965 sock_alloc_inode+0x1b/0xb0 net/socket.c:253 alloc_inode fs/inode.c:233 [inline] new_inode_pseudo+0x62/0x210 fs/inode.c:968 sock_alloc net/socket.c:574 [inline] __sock_create+0x12c/0x770 net/socket.c:1400 Memory state around the buggy address: ffff888111449700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888111449780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888111449800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888111449880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111449900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 392 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: 392 Comm: syz.2.17 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:pppol2tp_sock_to_session+0x167/0x1b0 net/l2tp/l2tp_ppp.c:156 Code: 5d c3 e8 fc 0b 36 fd be 02 00 00 00 eb 0a e8 f0 0b 36 fd be 01 00 00 00 4c 89 f7 e8 a3 76 0f fe e9 0f ff ff ff e8 d9 0b 36 fd <0f> 0b 48 89 df e8 ef 00 00 00 eb bd e8 c8 0b 36 fd 4c 89 f7 be 03 RSP: 0018:ffffc900042efd68 EFLAGS: 00010293 RAX: ffffffff842e9627 RBX: ffff888110cfd000 RCX: ffff888110ee4f00 RDX: 0000000000000000 RSI: 000000000ac42aa0 RDI: 000000000c04eb7d RBP: ffffc900042efd88 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff0dcf648 R12: dffffc0000000000 R13: dffffc0000000000 R14: 000000000ac42aa0 R15: ffff888111449800 FS: 0000555582d52500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b2a403000 CR3: 00000001113c7000 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: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: 0033:0x7f6b2965ae59 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:00007ffd64b4aa78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffd64b4ab60 RCX: 00007f6b2965ae59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 0000000000006ee9 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b32c20000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6b298d3fac R14: 00007f6b298d3fa8 R15: 00007f6b298d3fa0 ---[ end trace 44d1c7c7ae224bca ]--- 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 ffff888111449800 by task syz.2.17/392 CPU: 0 PID: 392 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 __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: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: 0033:0x7f6b2965ae59 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:00007ffd64b4aa78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffd64b4ab60 RCX: 00007f6b2965ae59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 0000000000006ee9 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b32c20000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6b298d3fac R14: 00007f6b298d3fa8 R15: 00007f6b298d3fa0 Allocated by task 392: 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 333: 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 ffff888111449800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff888111449800, ffff888111449a00) The buggy address belongs to the page: page:ffffea0004451200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111448 head:ffffea0004451200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 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 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 365, ts 28406685763, free_ts 28386269459 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:3672 ip6_route_add+0x27/0x130 net/ipv6/route.c:3768 addrconf_prefix_route net/ipv6/addrconf.c:2463 [inline] fixup_permanent_addr net/ipv6/addrconf.c:3519 [inline] addrconf_permanent_addr+0x635/0x940 net/ipv6/addrconf.c:3543 addrconf_notify+0x752/0xea0 net/ipv6/addrconf.c:3611 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:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers net/core/dev.c:2080 [inline] __dev_notify_flags+0x2f4/0x5b0 net/core/dev.c:8585 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8623 do_setlink+0xb19/0x29a0 net/core/rtnetlink.c:2736 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 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x150/0x180 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x15a/0x2d0 mm/slub.c:2965 sock_alloc_inode+0x1b/0xb0 net/socket.c:253 alloc_inode fs/inode.c:233 [inline] new_inode_pseudo+0x62/0x210 fs/inode.c:968 sock_alloc net/socket.c:574 [inline] __sock_create+0x12c/0x770 net/socket.c:1400 Memory state around the buggy address: ffff888111449700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888111449780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888111449800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888111449880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111449900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 392 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: 392 Comm: syz.2.17 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:pppol2tp_sock_to_session+0x167/0x1b0 net/l2tp/l2tp_ppp.c:156 Code: 5d c3 e8 fc 0b 36 fd be 02 00 00 00 eb 0a e8 f0 0b 36 fd be 01 00 00 00 4c 89 f7 e8 a3 76 0f fe e9 0f ff ff ff e8 d9 0b 36 fd <0f> 0b 48 89 df e8 ef 00 00 00 eb bd e8 c8 0b 36 fd 4c 89 f7 be 03 RSP: 0018:ffffc900042efd68 EFLAGS: 00010293 RAX: ffffffff842e9627 RBX: ffff888110cfd000 RCX: ffff888110ee4f00 RDX: 0000000000000000 RSI: 000000000ac42aa0 RDI: 000000000c04eb7d RBP: ffffc900042efd88 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff0dcf648 R12: dffffc0000000000 R13: dffffc0000000000 R14: 000000000ac42aa0 R15: ffff888111449800 FS: 0000555582d52500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b2a403000 CR3: 00000001113c7000 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: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: 0033:0x7f6b2965ae59 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:00007ffd64b4aa78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffd64b4ab60 RCX: 00007f6b2965ae59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 0000000000006ee9 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b32c20000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6b298d3fac R14: 00007f6b298d3fa8 R15: 00007f6b298d3fa0 ---[ end trace 44d1c7c7ae224bca ]---