Extracting prog: 44.584151018s
Minimizing prog: 3m45.261379963s
Simplifying prog options: 0s
Extracting C: 30.869165629s
Simplifying C: 2m48.368936512s


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$pppl2tp-ioctl$BTRFS_IOC_DEV_INFO
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e)
ioctl$BTRFS_IOC_DEV_INFO(r0, 0xd000941e, 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=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$pppl2tp
detailed listing:
executing program 0:
r0 = socket$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=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-ioctl$BTRFS_IOC_DEV_INFO
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
socket$inet6_udp(0xa, 0x2, 0x0)
ioctl$BTRFS_IOC_DEV_INFO(r0, 0xd000941e, 0x0)

program did not crash
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$pppl2tp-connect$pppl2tp-ioctl$BTRFS_IOC_DEV_INFO
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, 0xffffffffffffffff, {0x2, 0x0, @dev}, 0x2}}, 0x2e)
ioctl$BTRFS_IOC_DEV_INFO(r0, 0xd000941e, 0x0)

program did not crash
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$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_DEV_INFO
detailed listing:
executing program 0:
r0 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(0xffffffffffffffff, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r0, {0x2, 0x0, @dev}, 0x2}}, 0x2e)
ioctl$BTRFS_IOC_DEV_INFO(0xffffffffffffffff, 0xd000941e, 0x0)

program did not crash
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$pppl2tp-ioctl$BTRFS_IOC_DEV_INFO
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_DEV_INFO(r0, 0xd000941e, 0x0)

program did not crash
extracting C reproducer
testing compiled C 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$pppl2tp-ioctl$BTRFS_IOC_DEV_INFO
program crashed: KASAN: use-after-free Write in pppol2tp_release
simplifying C reproducer
testing compiled C program (duration=30s, {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_DEV_INFO
program crashed: KASAN: use-after-free Write in pppol2tp_release
testing compiled C program (duration=30s, {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_DEV_INFO
program crashed: KASAN: use-after-free Write in pppol2tp_release
testing compiled C program (duration=30s, {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_DEV_INFO
program crashed: KASAN: use-after-free Write in pppol2tp_release
testing compiled C program (duration=30s, {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$pppl2tp-ioctl$BTRFS_IOC_DEV_INFO
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=30s, {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:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$pppl2tp-socket$inet6_udp-connect$pppl2tp-ioctl$BTRFS_IOC_DEV_INFO
program did not crash
testing compiled C program (duration=30s, {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: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_DEV_INFO
program did not crash
testing program (duration=30s, {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_DEV_INFO
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e)
ioctl$BTRFS_IOC_DEV_INFO(r0, 0xd000941e, 0x0)

program crashed: KASAN: use-after-free Write in rcu_segcblist_enqueue
validation run: crashed=true
testing program (duration=30s, {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_DEV_INFO
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e)
ioctl$BTRFS_IOC_DEV_INFO(r0, 0xd000941e, 0x0)

program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue
validation run: crashed=true
testing program (duration=30s, {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_DEV_INFO
detailed listing:
executing program 0:
r0 = socket$pppl2tp(0x18, 0x1, 0x1)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$pppl2tp(r0, &(0x7f0000000000)=@pppol2tpv3={0x18, 0x1, {0x3, r1, {0x2, 0x0, @dev}, 0x2}}, 0x2e)
ioctl$BTRFS_IOC_DEV_INFO(r0, 0xd000941e, 0x0)

program crashed: KASAN: use-after-free Read in rcu_cblist_dequeue
validation run: crashed=true
reproducing took 9m38.306184311s
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 ffff888129615190 by task syz-execprog/296

CPU: 1 PID: 296 Comm: syz-execprog Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <IRQ>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0x10f/0x150 mm/kasan/report.c:444
 __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+0x47d/0xbf0 kernel/rcu/tree.c:2512
 rcu_core+0x4a3/0xef0 kernel/rcu/tree.c:2763
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 __do_softirq kernel/softirq.c:621 [inline]
 invoke_softirq kernel/softirq.c:443 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:arch_stack_walk+0xa/0x140 arch/x86/kernel/stacktrace.c:17
Code: 31 c0 ee 31 c0 ee eb b1 31 c0 e6 8b eb 8b 31 c0 e6 d4 48 c7 c7 a0 4d 0f 87 e8 72 4a 89 03 5d c3 55 48 89 e5 41 57 41 56 41 54 <53> 48 83 ec 68 49 89 cf 49 89 d4 48 89 f3 49 89 fe 65 48 8b 04 25
RSP: 0018:ffffc90000987018 EFLAGS: 00000246
RAX: ffffc90000987060 RBX: 1ffff92000130e08 RCX: 0000000000000000
RDX: ffff888107b88000 RSI: ffffc90000987060 RDI: ffffffff8159c9c0
RBP: ffffc90000987030 R08: ffffc9000098719f R09: ffffc90000987120
R10: dffffc0000000000 R11: fffff52000130e34 R12: dffffc0000000000
R13: 1ffff11020f710b2 R14: dffffc0000000000 R15: 1ffff92000130e20
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 save_stack+0x121/0x230 mm/page_owner.c:139
 __reset_page_owner+0x35/0x190 mm/page_owner.c:156
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1477 [inline]
 free_pcp_prepare mm/page_alloc.c:1549 [inline]
 free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3540
 free_unref_page_list+0x138/0x9e0 mm/page_alloc.c:3677
 release_pages+0x1264/0x12c0 mm/swap.c:1033
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:320
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu+0xdf/0x190 mm/mmu_gather.c:247
 zap_pte_range mm/memory.c:1528 [inline]
 zap_pmd_range mm/memory.c:1577 [inline]
 zap_pud_range mm/memory.c:1606 [inline]
 zap_p4d_range mm/memory.c:1627 [inline]
 unmap_page_range+0x1c25/0x1e00 mm/memory.c:1648
 unmap_single_vma mm/memory.c:1693 [inline]
 unmap_vmas+0x26d/0x380 mm/memory.c:1725
 exit_mmap+0x412/0x8b0 mm/mmap.c:3245
 __mmput+0x92/0x300 kernel/fork.c:1191
 mmput+0x50/0x150 kernel/fork.c:1214
 exit_mm kernel/exit.c:561 [inline]
 do_exit+0xacc/0x29a0 kernel/exit.c:883
 do_group_exit+0x149/0x310 kernel/exit.c:1010
 get_signal+0x64f/0x1430 kernel/signal.c:2920
 arch_do_signal_or_restart+0xe2/0x1100 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:157 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x48f2e3
Code: Unable to access opcode bytes at RIP 0x48f2b9.
RSP: 002b:0000164d1c21dcd8 EFLAGS: 00000286 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 000000000048f2e3
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000164d1c1ff160
RBP: 0000164d1c21dd20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 0000164d1c21dd30
R13: 0000164d22f9e200 R14: 0000164d1c1c6f00 R15: ffffffffffffffff
 </TASK>

Allocated by task 371:
 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:433 [inline]
 ____kasan_kmalloc mm/kasan/common.c:512 [inline]
 __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 __kmalloc+0x13d/0x2c0 mm/slub.c:4436
 kmalloc include/linux/slab.h:624 [inline]
 kzalloc include/linux/slab.h:750 [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:1923 [inline]
 __sys_connect+0x3cb/0x450 net/socket.c:1940
 __do_sys_connect net/socket.c:1950 [inline]
 __se_sys_connect net/socket.c:1947 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:1947
 x64_sys_call+0x7c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:43
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 45:
 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:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1728 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754
 slab_free mm/slub.c:3526 [inline]
 kfree+0xc4/0x270 mm/slub.c:4588
 l2tp_session_free net/l2tp/l2tp_core.c:168 [inline]
 l2tp_session_put+0xaf/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+0x6c8/0xbb0 kernel/workqueue.c:2328
 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475
 kthread+0x3f5/0x4f0 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu_common kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x10b/0xf60 kernel/rcu/tree.c:3129
 pppol2tp_release+0x1e3/0x2b0 net/l2tp/l2tp_ppp.c:447
 __sock_release net/socket.c:649 [inline]
 sock_close+0xb8/0x200 net/socket.c:1336
 __fput+0x22b/0x900 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:184
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888129615000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 400 bytes inside of
 512-byte region [ffff888129615000, ffff888129615200)
The buggy address belongs to the page:
page:ffffea0004a58500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x129614
head:ffffea0004a58500 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 367, ts 23054012047, free_ts 22341265421
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2610
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2616
 get_page_from_freelist+0x2d42/0x2dd0 mm/page_alloc.c:4492
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5829
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1937 [inline]
 new_slab+0xa0/0x4d0 mm/slub.c:2000
 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033
 __slab_alloc+0x49/0x90 mm/slub.c:3120
 slab_alloc_node mm/slub.c:3211 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954
 kmalloc_reserve net/core/skbuff.c:357 [inline]
 __alloc_skb+0x210/0x730 net/core/skbuff.c:428
 alloc_skb include/linux/skbuff.h:1183 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 netlink_ack+0x35c/0xb10 net/netlink/af_netlink.c:2455
 netlink_rcv_skb+0x267/0x430 net/netlink/af_netlink.c:2526
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5680
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1923
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2063
 __do_sys_sendto net/socket.c:2075 [inline]
 __se_sys_sendto net/socket.c:2071 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2071
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1477 [inline]
 free_pcp_prepare mm/page_alloc.c:1549 [inline]
 free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3540
 free_unref_page+0xae/0x540 mm/page_alloc.c:3622
 free_the_page mm/page_alloc.c:808 [inline]
 __free_pages+0x6c/0x100 mm/page_alloc.c:5905
 __vunmap+0x801/0x980 mm/vmalloc.c:2660
 __vfree mm/vmalloc.c:2709 [inline]
 vfree+0x8b/0xc0 mm/vmalloc.c:2740
 kcov_put kernel/kcov.c:422 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:524
 __fput+0x22b/0x900 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xb70/0x29a0 kernel/exit.c:896
 do_group_exit+0x149/0x310 kernel/exit.c:1010
 get_signal+0x64f/0x1430 kernel/signal.c:2920
 arch_do_signal_or_restart+0xe2/0x1100 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:157 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310

Memory state around the buggy address:
 ffff888129615080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888129615100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888129615180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888129615200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888129615280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	31 c0                	xor    %eax,%eax
   2:	ee                   	out    %al,(%dx)
   3:	31 c0                	xor    %eax,%eax
   5:	ee                   	out    %al,(%dx)
   6:	eb b1                	jmp    0xffffffb9
   8:	31 c0                	xor    %eax,%eax
   a:	e6 8b                	out    %al,$0x8b
   c:	eb 8b                	jmp    0xffffff99
   e:	31 c0                	xor    %eax,%eax
  10:	e6 d4                	out    %al,$0xd4
  12:	48 c7 c7 a0 4d 0f 87 	mov    $0xffffffff870f4da0,%rdi
  19:	e8 72 4a 89 03       	call   0x3894a90
  1e:	5d                   	pop    %rbp
  1f:	c3                   	ret
  20:	55                   	push   %rbp
  21:	48 89 e5             	mov    %rsp,%rbp
  24:	41 57                	push   %r15
  26:	41 56                	push   %r14
  28:	41 54                	push   %r12
* 2a:	53                   	push   %rbx <-- trapping instruction
  2b:	48 83 ec 68          	sub    $0x68,%rsp
  2f:	49 89 cf             	mov    %rcx,%r15
  32:	49 89 d4             	mov    %rdx,%r12
  35:	48 89 f3             	mov    %rsi,%rbx
  38:	49 89 fe             	mov    %rdi,%r14
  3b:	65                   	gs
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	04 25                	add    $0x25,%al

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 ffff888129615190 by task syz-execprog/296

CPU: 1 PID: 296 Comm: syz-execprog Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <IRQ>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0x10f/0x150 mm/kasan/report.c:444
 __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+0x47d/0xbf0 kernel/rcu/tree.c:2512
 rcu_core+0x4a3/0xef0 kernel/rcu/tree.c:2763
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 __do_softirq kernel/softirq.c:621 [inline]
 invoke_softirq kernel/softirq.c:443 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:arch_stack_walk+0xa/0x140 arch/x86/kernel/stacktrace.c:17
Code: 31 c0 ee 31 c0 ee eb b1 31 c0 e6 8b eb 8b 31 c0 e6 d4 48 c7 c7 a0 4d 0f 87 e8 72 4a 89 03 5d c3 55 48 89 e5 41 57 41 56 41 54 <53> 48 83 ec 68 49 89 cf 49 89 d4 48 89 f3 49 89 fe 65 48 8b 04 25
RSP: 0018:ffffc90000987018 EFLAGS: 00000246
RAX: ffffc90000987060 RBX: 1ffff92000130e08 RCX: 0000000000000000
RDX: ffff888107b88000 RSI: ffffc90000987060 RDI: ffffffff8159c9c0
RBP: ffffc90000987030 R08: ffffc9000098719f R09: ffffc90000987120
R10: dffffc0000000000 R11: fffff52000130e34 R12: dffffc0000000000
R13: 1ffff11020f710b2 R14: dffffc0000000000 R15: 1ffff92000130e20
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 save_stack+0x121/0x230 mm/page_owner.c:139
 __reset_page_owner+0x35/0x190 mm/page_owner.c:156
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1477 [inline]
 free_pcp_prepare mm/page_alloc.c:1549 [inline]
 free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3540
 free_unref_page_list+0x138/0x9e0 mm/page_alloc.c:3677
 release_pages+0x1264/0x12c0 mm/swap.c:1033
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:320
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu+0xdf/0x190 mm/mmu_gather.c:247
 zap_pte_range mm/memory.c:1528 [inline]
 zap_pmd_range mm/memory.c:1577 [inline]
 zap_pud_range mm/memory.c:1606 [inline]
 zap_p4d_range mm/memory.c:1627 [inline]
 unmap_page_range+0x1c25/0x1e00 mm/memory.c:1648
 unmap_single_vma mm/memory.c:1693 [inline]
 unmap_vmas+0x26d/0x380 mm/memory.c:1725
 exit_mmap+0x412/0x8b0 mm/mmap.c:3245
 __mmput+0x92/0x300 kernel/fork.c:1191
 mmput+0x50/0x150 kernel/fork.c:1214
 exit_mm kernel/exit.c:561 [inline]
 do_exit+0xacc/0x29a0 kernel/exit.c:883
 do_group_exit+0x149/0x310 kernel/exit.c:1010
 get_signal+0x64f/0x1430 kernel/signal.c:2920
 arch_do_signal_or_restart+0xe2/0x1100 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:157 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x48f2e3
Code: Unable to access opcode bytes at RIP 0x48f2b9.
RSP: 002b:0000164d1c21dcd8 EFLAGS: 00000286 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 000000000048f2e3
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000164d1c1ff160
RBP: 0000164d1c21dd20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 0000164d1c21dd30
R13: 0000164d22f9e200 R14: 0000164d1c1c6f00 R15: ffffffffffffffff
 </TASK>

Allocated by task 371:
 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:433 [inline]
 ____kasan_kmalloc mm/kasan/common.c:512 [inline]
 __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 __kmalloc+0x13d/0x2c0 mm/slub.c:4436
 kmalloc include/linux/slab.h:624 [inline]
 kzalloc include/linux/slab.h:750 [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:1923 [inline]
 __sys_connect+0x3cb/0x450 net/socket.c:1940
 __do_sys_connect net/socket.c:1950 [inline]
 __se_sys_connect net/socket.c:1947 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:1947
 x64_sys_call+0x7c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:43
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 45:
 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:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1728 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754
 slab_free mm/slub.c:3526 [inline]
 kfree+0xc4/0x270 mm/slub.c:4588
 l2tp_session_free net/l2tp/l2tp_core.c:168 [inline]
 l2tp_session_put+0xaf/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+0x6c8/0xbb0 kernel/workqueue.c:2328
 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475
 kthread+0x3f5/0x4f0 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu_common kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x10b/0xf60 kernel/rcu/tree.c:3129
 pppol2tp_release+0x1e3/0x2b0 net/l2tp/l2tp_ppp.c:447
 __sock_release net/socket.c:649 [inline]
 sock_close+0xb8/0x200 net/socket.c:1336
 __fput+0x22b/0x900 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:184
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888129615000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 400 bytes inside of
 512-byte region [ffff888129615000, ffff888129615200)
The buggy address belongs to the page:
page:ffffea0004a58500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x129614
head:ffffea0004a58500 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 367, ts 23054012047, free_ts 22341265421
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2610
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2616
 get_page_from_freelist+0x2d42/0x2dd0 mm/page_alloc.c:4492
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5829
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1937 [inline]
 new_slab+0xa0/0x4d0 mm/slub.c:2000
 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033
 __slab_alloc+0x49/0x90 mm/slub.c:3120
 slab_alloc_node mm/slub.c:3211 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954
 kmalloc_reserve net/core/skbuff.c:357 [inline]
 __alloc_skb+0x210/0x730 net/core/skbuff.c:428
 alloc_skb include/linux/skbuff.h:1183 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 netlink_ack+0x35c/0xb10 net/netlink/af_netlink.c:2455
 netlink_rcv_skb+0x267/0x430 net/netlink/af_netlink.c:2526
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5680
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1923
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2063
 __do_sys_sendto net/socket.c:2075 [inline]
 __se_sys_sendto net/socket.c:2071 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2071
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1477 [inline]
 free_pcp_prepare mm/page_alloc.c:1549 [inline]
 free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3540
 free_unref_page+0xae/0x540 mm/page_alloc.c:3622
 free_the_page mm/page_alloc.c:808 [inline]
 __free_pages+0x6c/0x100 mm/page_alloc.c:5905
 __vunmap+0x801/0x980 mm/vmalloc.c:2660
 __vfree mm/vmalloc.c:2709 [inline]
 vfree+0x8b/0xc0 mm/vmalloc.c:2740
 kcov_put kernel/kcov.c:422 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:524
 __fput+0x22b/0x900 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xb70/0x29a0 kernel/exit.c:896
 do_group_exit+0x149/0x310 kernel/exit.c:1010
 get_signal+0x64f/0x1430 kernel/signal.c:2920
 arch_do_signal_or_restart+0xe2/0x1100 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:157 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310

Memory state around the buggy address:
 ffff888129615080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888129615100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888129615180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888129615200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888129615280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	31 c0                	xor    %eax,%eax
   2:	ee                   	out    %al,(%dx)
   3:	31 c0                	xor    %eax,%eax
   5:	ee                   	out    %al,(%dx)
   6:	eb b1                	jmp    0xffffffb9
   8:	31 c0                	xor    %eax,%eax
   a:	e6 8b                	out    %al,$0x8b
   c:	eb 8b                	jmp    0xffffff99
   e:	31 c0                	xor    %eax,%eax
  10:	e6 d4                	out    %al,$0xd4
  12:	48 c7 c7 a0 4d 0f 87 	mov    $0xffffffff870f4da0,%rdi
  19:	e8 72 4a 89 03       	call   0x3894a90
  1e:	5d                   	pop    %rbp
  1f:	c3                   	ret
  20:	55                   	push   %rbp
  21:	48 89 e5             	mov    %rsp,%rbp
  24:	41 57                	push   %r15
  26:	41 56                	push   %r14
  28:	41 54                	push   %r12
* 2a:	53                   	push   %rbx <-- trapping instruction
  2b:	48 83 ec 68          	sub    $0x68,%rsp
  2f:	49 89 cf             	mov    %rcx,%r15
  32:	49 89 d4             	mov    %rdx,%r12
  35:	48 89 f3             	mov    %rsi,%rbx
  38:	49 89 fe             	mov    %rdi,%r14
  3b:	65                   	gs
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	04 25                	add    $0x25,%al