Extracting prog: 1m1.472865006s Minimizing prog: 7m57.746307038s Simplifying prog options: 0s Extracting C: 39.04969958s Simplifying C: 5m44.729236944s extracting reproducer from 84 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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-connect$pppl2tp-socket$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL-ioctl$BTRFS_IOC_BALANCE_PROGRESS-ioctl$BTRFS_IOC_SNAP_CREATE_V2-connect$pppl2tp-bpf$PROG_LOAD detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) r2 = socket$pppl2tp(0x18, 0x1, 0x1) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) ioctl$BTRFS_IOC_BALANCE_PROGRESS(r1, 0x84009422, &(0x7f0000000280)={0x0, 0x0, {0x0, @struct}, {0x0, @struct}, {0x0, @struct, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @struct}}) ioctl$BTRFS_IOC_SNAP_CREATE_V2(r0, 0x50009417, &(0x7f00000008c0)={{r2}, r3, 0x0, @inherit={0x80, &(0x7f0000000200)={0x0, 0x7, 0x4, 0x7f, {0x0, 0x9, 0x6, 0x5, 0x5}, [0x0, 0x80, 0x8, 0x3, 0x1, 0x10000, 0x4]}}, @devid=r4}) connect$pppl2tp(r2, &(0x7f0000000040)=@pppol2tpv3={0x18, 0x1, {0x3, 0xffffffffffffffff, {0x2, 0x4e21, @broadcast}, 0x2, 0x9800, 0xfffffffb}}, 0x2e) bpf$PROG_LOAD(0x5, &(0x7f0000000800)={0x11, 0xb, &(0x7f0000000000)=ANY=[@ANYBLOB="1800000000000800000000004b00000018010000696c6c2500000000002020207b1af8ff00000000bfa100000000000007010007000000000000000008000000b7030000ffffffff850000002d0000009500000000000000"], &(0x7f00000001c0)='GPL\x00', 0x0, 0x0, 0x0, 0x40f00, 0x2, '\x00', 0x0, @fallback=0xf, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, 0x94) program crashed: KASAN: use-after-free Read in l2tp_tunnel_get_session single: successfully extracted reproducer found reproducer with 10 syscalls minimizing guilty program testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-connect$pppl2tp-socket$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL-ioctl$BTRFS_IOC_BALANCE_PROGRESS-ioctl$BTRFS_IOC_SNAP_CREATE_V2-connect$pppl2tp detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) r2 = socket$pppl2tp(0x18, 0x1, 0x1) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) ioctl$BTRFS_IOC_BALANCE_PROGRESS(r1, 0x84009422, &(0x7f0000000280)={0x0, 0x0, {0x0, @struct}, {0x0, @struct}, {0x0, @struct, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @struct}}) ioctl$BTRFS_IOC_SNAP_CREATE_V2(r0, 0x50009417, &(0x7f00000008c0)={{r2}, r3, 0x0, @inherit={0x80, &(0x7f0000000200)={0x0, 0x7, 0x4, 0x7f, {0x0, 0x9, 0x6, 0x5, 0x5}, [0x0, 0x80, 0x8, 0x3, 0x1, 0x10000, 0x4]}}, @devid=r4}) connect$pppl2tp(r2, &(0x7f0000000040)=@pppol2tpv3={0x18, 0x1, {0x3, 0xffffffffffffffff, {0x2, 0x4e21, @broadcast}, 0x2, 0x9800, 0xfffffffb}}, 0x2e) program crashed: KASAN: use-after-free Read in l2tp_tunnel_get_session testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-connect$pppl2tp-socket$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL-ioctl$BTRFS_IOC_BALANCE_PROGRESS-ioctl$BTRFS_IOC_SNAP_CREATE_V2 detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) r2 = socket$pppl2tp(0x18, 0x1, 0x1) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) ioctl$BTRFS_IOC_BALANCE_PROGRESS(r1, 0x84009422, &(0x7f0000000280)={0x0, 0x0, {0x0, @struct}, {0x0, @struct}, {0x0, @struct, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @struct}}) ioctl$BTRFS_IOC_SNAP_CREATE_V2(r0, 0x50009417, &(0x7f00000008c0)={{r2}, r3, 0x0, @inherit={0x80, &(0x7f0000000200)={0x0, 0x7, 0x4, 0x7f, {0x0, 0x9, 0x6, 0x5, 0x5}, [0x0, 0x80, 0x8, 0x3, 0x1, 0x10000, 0x4]}}, @devid=r4}) program crashed: KASAN: use-after-free Read in l2tp_tunnel_del_work testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-connect$pppl2tp-socket$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL-ioctl$BTRFS_IOC_BALANCE_PROGRESS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) socket$pppl2tp(0x18, 0x1, 0x1) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) ioctl$BTRFS_IOC_BALANCE_PROGRESS(r1, 0x84009422, &(0x7f0000000280)={0x0, 0x0, {0x0, @struct}, {0x0, @struct}, {0x0, @struct, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @struct}}) program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-connect$pppl2tp-socket$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) socket$pppl2tp(0x18, 0x1, 0x1) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-connect$pppl2tp-socket$pppl2tp detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) socket$pppl2tp(0x18, 0x1, 0x1) program did not crash testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-socket$inet6_udp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) socket$inet6_udp(0xa, 0x2, 0x0) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) program did not crash testing program (duration=33.578741238s, {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$pppl2tp-openat$selinux_avc_hash_stats-connect$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) openat$selinux_avc_hash_stats(0xffffffffffffff9c, 0x0, 0x0, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, 0xffffffffffffffff, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) program did not crash testing program (duration=33.578741238s, {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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing program (duration=33.578741238s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(0xffffffffffffffff, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r0, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(0xffffffffffffffff, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) program did not crash testing program (duration=33.578741238s, {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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, 0x0, 0x0) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, &(0x7f0000000080)={"61fcaa4458b27994e821941d062ebe68", 0x0, 0x0, {0xffffffff}, {0x5a, 0x39}, 0x8, [0x0, 0x80, 0x4, 0x93, 0xfffffffffffff000, 0x100000000, 0x5, 0x3, 0x7, 0x400, 0x7, 0x9, 0x9, 0x2, 0x574a, 0x1000]}) program did not crash testing program (duration=33.578741238s, {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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release extracting C reproducer testing compiled C program (duration=33.578741238s, {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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release simplifying C reproducer testing compiled C program (duration=33.578741238s, {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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=33.578741238s, {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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=33.578741238s, {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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program did not crash testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:false 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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:true UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session testing compiled C program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release validation run: crashed=true testing program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release validation run: crashed=true testing program (duration=33.578741238s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none 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$pppl2tp-ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000740)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x4e24, @broadcast}, 0x2, 0x0, 0x4}}, 0x2e) ioctl$BTRFS_IOC_SET_RECEIVED_SUBVOL(r0, 0xc0c89425, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release validation run: crashed=true reproducing took 17m4.795321411s repro crashed as (corrupted=false): ================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:102 [inline] BUG: KASAN: use-after-free in atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1779 [inline] BUG: KASAN: use-after-free in __mutex_trylock_fast kernel/locking/mutex.c:176 [inline] BUG: KASAN: use-after-free in mutex_lock+0x86/0x1b0 kernel/locking/mutex.c:295 Write of size 8 at addr ffff88810f168950 by task syz.2.17/375 CPU: 1 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 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:102 [inline] atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1779 [inline] __mutex_trylock_fast kernel/locking/mutex.c:176 [inline] mutex_lock+0x86/0x1b0 kernel/locking/mutex.c:295 pppol2tp_release+0x178/0x2b0 net/l2tp/l2tp_ppp.c:441 __sock_release net/socket.c:652 [inline] sock_close+0xc9/0x220 net/socket.c:1389 __fput+0x1fd/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f16cf99e0d9 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:00007ffc7fba5e18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffc7fba5f00 RCX: 00007f16cf99e0d9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000066de R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b33120000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f16cfc25fac R14: 00007f16cfc25fa8 R15: 00007f16cfc25fa0 Allocated by task 375: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:380 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc+0xb4/0x1e0 mm/slab_common.c:951 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] l2tp_session_create+0x38/0xbd0 net/l2tp/l2tp_core.c:1609 pppol2tp_connect+0xbf5/0x1640 net/l2tp/l2tp_ppp.c:771 __sys_connect_file net/socket.c:2000 [inline] __sys_connect+0x3da/0x460 net/socket.c:2017 __do_sys_connect net/socket.c:2027 [inline] __se_sys_connect net/socket.c:2024 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2024 x64_sys_call+0x88d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:43 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 375: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728 kfree+0x6f/0xf0 mm/slab_common.c:990 l2tp_session_free net/l2tp/l2tp_core.c:168 [inline] l2tp_session_put+0xaf/0x1a0 net/l2tp/l2tp_core.c:193 l2tp_session_delete+0x3df/0x4d0 net/l2tp/l2tp_core.c:1582 pppol2tp_release+0x169/0x2b0 net/l2tp/l2tp_ppp.c:438 __sock_release net/socket.c:652 [inline] sock_close+0xc9/0x220 net/socket.c:1389 __fput+0x1fd/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88810f168800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 336 bytes inside of 512-byte region [ffff88810f168800, ffff88810f168a00) The buggy address belongs to the physical page: page:ffffea00043c5a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f168 head:ffffea00043c5a00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100042f00 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 370, tgid 370 (syz-executor), ts 26355933386, free_ts 25739782139 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4586 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5930 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] find_css_set+0x937/0x15c0 kernel/cgroup/cgroup.c:1252 cgroup_migrate_prepare_dst+0xc4/0xa00 kernel/cgroup/cgroup.c:2873 cgroup_attach_task+0x298/0x520 kernel/cgroup/cgroup.c:2979 __cgroup1_procs_write+0x314/0x520 kernel/cgroup/cgroup-v1.c:524 cgroup1_procs_write+0x2a/0x40 kernel/cgroup/cgroup-v1.c:538 cgroup_file_write+0x2a2/0x590 kernel/cgroup/cgroup.c:4143 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1580 [inline] free_pcp_prepare mm/page_alloc.c:1654 [inline] free_unref_page_prepare+0x80c/0x820 mm/page_alloc.c:3621 free_unref_page+0x93/0x530 mm/page_alloc.c:3719 free_the_page mm/page_alloc.c:863 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:6020 __vunmap+0xa3c/0xc00 mm/vmalloc.c:2739 __vfree mm/vmalloc.c:2788 [inline] vfree+0x61/0x90 mm/vmalloc.c:2819 kcov_put kernel/kcov.c:437 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:533 __fput+0x1fd/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xaf2/0x2850 kernel/exit.c:887 do_group_exit+0x21b/0x2e0 kernel/exit.c:1030 get_signal+0x167c/0x1700 kernel/signal.c:2895 arch_do_signal_or_restart+0xd1/0x11c0 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 Memory state around the buggy address: ffff88810f168800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810f168880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810f168900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810f168980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810f168a00: 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:102 [inline] BUG: KASAN: use-after-free in atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1779 [inline] BUG: KASAN: use-after-free in __mutex_trylock_fast kernel/locking/mutex.c:176 [inline] BUG: KASAN: use-after-free in mutex_lock+0x86/0x1b0 kernel/locking/mutex.c:295 Write of size 8 at addr ffff88810f168950 by task syz.2.17/375 CPU: 1 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 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:102 [inline] atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1779 [inline] __mutex_trylock_fast kernel/locking/mutex.c:176 [inline] mutex_lock+0x86/0x1b0 kernel/locking/mutex.c:295 pppol2tp_release+0x178/0x2b0 net/l2tp/l2tp_ppp.c:441 __sock_release net/socket.c:652 [inline] sock_close+0xc9/0x220 net/socket.c:1389 __fput+0x1fd/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f16cf99e0d9 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:00007ffc7fba5e18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffc7fba5f00 RCX: 00007f16cf99e0d9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000066de R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b33120000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f16cfc25fac R14: 00007f16cfc25fa8 R15: 00007f16cfc25fa0 Allocated by task 375: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:380 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc+0xb4/0x1e0 mm/slab_common.c:951 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] l2tp_session_create+0x38/0xbd0 net/l2tp/l2tp_core.c:1609 pppol2tp_connect+0xbf5/0x1640 net/l2tp/l2tp_ppp.c:771 __sys_connect_file net/socket.c:2000 [inline] __sys_connect+0x3da/0x460 net/socket.c:2017 __do_sys_connect net/socket.c:2027 [inline] __se_sys_connect net/socket.c:2024 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2024 x64_sys_call+0x88d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:43 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 375: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728 kfree+0x6f/0xf0 mm/slab_common.c:990 l2tp_session_free net/l2tp/l2tp_core.c:168 [inline] l2tp_session_put+0xaf/0x1a0 net/l2tp/l2tp_core.c:193 l2tp_session_delete+0x3df/0x4d0 net/l2tp/l2tp_core.c:1582 pppol2tp_release+0x169/0x2b0 net/l2tp/l2tp_ppp.c:438 __sock_release net/socket.c:652 [inline] sock_close+0xc9/0x220 net/socket.c:1389 __fput+0x1fd/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88810f168800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 336 bytes inside of 512-byte region [ffff88810f168800, ffff88810f168a00) The buggy address belongs to the physical page: page:ffffea00043c5a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f168 head:ffffea00043c5a00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100042f00 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 370, tgid 370 (syz-executor), ts 26355933386, free_ts 25739782139 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4586 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5930 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] find_css_set+0x937/0x15c0 kernel/cgroup/cgroup.c:1252 cgroup_migrate_prepare_dst+0xc4/0xa00 kernel/cgroup/cgroup.c:2873 cgroup_attach_task+0x298/0x520 kernel/cgroup/cgroup.c:2979 __cgroup1_procs_write+0x314/0x520 kernel/cgroup/cgroup-v1.c:524 cgroup1_procs_write+0x2a/0x40 kernel/cgroup/cgroup-v1.c:538 cgroup_file_write+0x2a2/0x590 kernel/cgroup/cgroup.c:4143 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1580 [inline] free_pcp_prepare mm/page_alloc.c:1654 [inline] free_unref_page_prepare+0x80c/0x820 mm/page_alloc.c:3621 free_unref_page+0x93/0x530 mm/page_alloc.c:3719 free_the_page mm/page_alloc.c:863 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:6020 __vunmap+0xa3c/0xc00 mm/vmalloc.c:2739 __vfree mm/vmalloc.c:2788 [inline] vfree+0x61/0x90 mm/vmalloc.c:2819 kcov_put kernel/kcov.c:437 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:533 __fput+0x1fd/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xaf2/0x2850 kernel/exit.c:887 do_group_exit+0x21b/0x2e0 kernel/exit.c:1030 get_signal+0x167c/0x1700 kernel/signal.c:2895 arch_do_signal_or_restart+0xd1/0x11c0 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 Memory state around the buggy address: ffff88810f168800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810f168880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810f168900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810f168980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810f168a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================