Extracting prog: 1m19.474570055s Minimizing prog: 3m28.477321362s Simplifying prog options: 0s Extracting C: 29.082508659s Simplifying C: 5m25.330534248s extracting reproducer from 1 programs testing a last program of every proc single: executing 1 programs separately with timeout 30s testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$PPPIOCGL2TPSTATS(r0, 0x80487436, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release single: successfully extracted reproducer found reproducer with 4 syscalls minimizing guilty program testing program (duration=35.198390599s, {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$pppl2tp detailed listing: executing program 0: r0 = socket$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) program did not crash testing program (duration=35.198390599s, {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-ioctl$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) socket$inet6_udp(0xa, 0x2, 0x0) ioctl$PPPIOCGL2TPSTATS(r0, 0x80487436, 0x0) program did not crash testing program (duration=35.198390599s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-connect$pppl2tp-ioctl$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, 0xffffffffffffffff, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$PPPIOCGL2TPSTATS(r0, 0x80487436, 0x0) program did not crash testing program (duration=35.198390599s, {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$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(0xffffffffffffffff, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r0, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$PPPIOCGL2TPSTATS(0xffffffffffffffff, 0x80487436, 0x0) program did not crash testing program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, 0x0, 0x0) ioctl$PPPIOCGL2TPSTATS(r0, 0x80487436, 0x0) program did not crash extracting C reproducer testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release simplifying C reproducer testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session a never seen crash title: KASAN: use-after-free Read in pppol2tp_sock_to_session, ignore testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Read in pppol2tp_sock_to_session a never seen crash title: KASAN: use-after-free Read in pppol2tp_sock_to_session, ignore testing compiled C program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing compiled C program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS program crashed: KASAN: use-after-free Write in pppol2tp_release testing program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$PPPIOCGL2TPSTATS(r0, 0x80487436, 0x0) program crashed: KASAN: use-after-free Write in pppol2tp_release validation run: crashed=true testing program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$PPPIOCGL2TPSTATS(r0, 0x80487436, 0x0) program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue validation run: crashed=true testing program (duration=35.198390599s, {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: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$pppl2tp-ioctl$PPPIOCGL2TPSTATS detailed listing: executing program 0: r0 = socket$pppl2tp(0x18, 0x1, 0x1) r1 = socket$inet6_udp(0xa, 0x2, 0x0) connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e) ioctl$PPPIOCGL2TPSTATS(r0, 0x80487436, 0x0) program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue validation run: crashed=true reproducing took 12m12.126424588s repro crashed as (corrupted=false): ================================================================== BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x6c/0xb0 kernel/rcu/rcu_segcblist.c:75 Read of size 8 at addr ffff88811141a990 by task ksoftirqd/0/12 CPU: 0 PID: 12 Comm: ksoftirqd/0 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_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 rcu_cblist_dequeue+0x6c/0xb0 kernel/rcu/rcu_segcblist.c:75 rcu_do_batch+0x3e2/0xaf0 kernel/rcu/tree.c:2483 rcu_core+0x50a/0xca0 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 run_ksoftirqd+0x23/0x30 kernel/softirq.c:670 smpboot_thread_fn+0x464/0x820 kernel/smpboot.c:164 kthread+0x324/0x3b0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 389: 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 9: 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 Last potentiall final repro crashed as (corrupted=false): ================================================================== BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x6c/0xb0 kernel/rcu/rcu_segcblist.c:75 Read of size 8 at addr ffff88811141a990 by task ksoftirqd/0/12 CPU: 0 PID: 12 Comm: ksoftirqd/0 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_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 rcu_cblist_dequeue+0x6c/0xb0 kernel/rcu/rcu_segcblist.c:75 rcu_do_batch+0x3e2/0xaf0 kernel/rcu/tree.c:2483 rcu_core+0x50a/0xca0 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 run_ksoftirqd+0x23/0x30 kernel/softirq.c:670 smpboot_thread_fn+0x464/0x820 kernel/smpboot.c:164 kthread+0x324/0x3b0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 389: 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 9: 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 Last potentiall