IPVS: set_ctl: invalid protocol: 95 127.0.0.1:20001 nq
IPVS: set_ctl: invalid protocol: 95 127.0.0.1:20001 nq
==================================================================
BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x176/0x1b0 kernel/locking/spinlock_debug.c:112
Read of size 4 at addr ffff8801ce88a55c by task syz-executor6/8843

CPU: 1 PID: 8843 Comm: syz-executor6 Not tainted 4.9.92-g4fb542f #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801ba647c10 ffffffff81d9c509 ffffea00073a2280 ffff8801ce88a55c
 0000000000000000 ffff8801ce88a55c ffff8801ce88a680 ffff8801ba647c48
 ffffffff8156556b ffff8801ce88a55c 0000000000000004 0000000000000000
Call Trace:
 [<ffffffff81d9c509>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d9c509>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8156556b>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff815657df>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff815657df>] kasan_report.cold.6+0xac/0x2f5 mm/kasan/report.c:412
 [<ffffffff815395d4>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 [<ffffffff81240f66>] debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
 [<ffffffff81240f66>] do_raw_spin_lock+0x176/0x1b0 kernel/locking/spinlock_debug.c:112
 [<ffffffff838d57f6>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:119 [inline]
 [<ffffffff838d57f6>] _raw_spin_lock_irqsave+0x56/0x62 kernel/locking/spinlock.c:159
 [<ffffffff82f0aa42>] skb_dequeue+0x22/0x180 net/core/skbuff.c:2380
 [<ffffffff8359772b>] l2tp_session_queue_purge+0xab/0x100 net/l2tp/l2tp_core.c:918
 [<ffffffff835a345b>] pppol2tp_release+0x1fb/0x2e0 net/l2tp/l2tp_ppp.c:492
 [<ffffffff82ef0ab6>] sock_release+0x96/0x1c0 net/socket.c:599
 [<ffffffff82ef0bf6>] sock_close+0x16/0x20 net/socket.c:1046
 [<ffffffff81575c83>] __fput+0x263/0x700 fs/file_table.c:208
 [<ffffffff815761a5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff81195dec>] task_work_run+0x10c/0x180 kernel/task_work.c:116
 [<ffffffff8100559c>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff8100559c>] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161
 [<ffffffff81007073>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff81007073>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff81007073>] do_syscall_32_irqs_on arch/x86/entry/common.c:331 [inline]
 [<ffffffff81007073>] do_fast_syscall_32+0x5c3/0x870 arch/x86/entry/common.c:387
 [<ffffffff838d6fd0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Allocated by task 8843:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609
 __kmalloc+0x11d/0x300 mm/slub.c:3741
 kmalloc include/linux/slab.h:495 [inline]
 kzalloc include/linux/slab.h:636 [inline]
 l2tp_session_create+0x38/0x1760 net/l2tp/l2tp_core.c:1843
 pppol2tp_connect+0x10c5/0x18e0 net/l2tp/l2tp_ppp.c:711
 SYSC_connect+0x1b8/0x300 net/socket.c:1562
 SyS_connect+0x24/0x30 net/socket.c:1543
 do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Freed by task 8844:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kfree+0xfb/0x310 mm/slub.c:3878
 l2tp_session_free+0x166/0x200 net/l2tp/l2tp_core.c:1770
 l2tp_session_dec_refcount_1 net/l2tp/l2tp_core.h:297 [inline]
 l2tp_tunnel_closeall+0x284/0x350 net/l2tp/l2tp_core.c:1373
 l2tp_udp_encap_destroy+0x87/0xe0 net/l2tp/l2tp_core.c:1394
 udpv6_destroy_sock+0xb1/0xd0 net/ipv6/udp.c:1336
 sk_common_release+0x6d/0x300 net/core/sock.c:2727
 udp_lib_close+0x15/0x20 include/net/udp.h:203
 inet_release+0xff/0x1d0 net/ipv4/af_inet.c:434
 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:440
 sock_release+0x96/0x1c0 net/socket.c:599
 sock_close+0x16/0x20 net/socket.c:1046
 __fput+0x263/0x700 fs/file_table.c:208
 ____fput+0x15/0x20 fs/file_table.c:244
 task_work_run+0x10c/0x180 kernel/task_work.c:116
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161
 prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 do_syscall_32_irqs_on arch/x86/entry/common.c:331 [inline]
 do_fast_syscall_32+0x5c3/0x870 arch/x86/entry/common.c:387
 entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

The buggy address belongs to the object at ffff8801ce88a500
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 92 bytes inside of
 512-byte region [ffff8801ce88a500, ffff8801ce88a700)
The buggy address belongs to the page:
page:ffffea00073a2280 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x8000000000004080(slab|head)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ce88a400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801ce88a480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801ce88a500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8801ce88a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801ce88a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================