l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 l2tp_core: tunl 4: sockfd_lookup(fd=4) returned -9 ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x32f9/0x4500 kernel/locking/lockdep.c:3365 Read of size 8 at addr ffff888087f035a0 by task syz-executor.5/11511 CPU: 0 PID: 11511 Comm: syz-executor.5 Not tainted 4.14.176-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xf7/0x13b lib/dump_stack.c:58 print_address_description.cold.7+0x9/0x1c9 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.8+0x11a/0x2d3 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 __lock_acquire+0x32f9/0x4500 kernel/locking/lockdep.c:3365 lock_acquire+0x173/0x400 kernel/locking/lockdep.c:3994 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:176 spin_lock_bh include/linux/spinlock.h:322 [inline] lock_sock_nested+0x3a/0x100 net/core/sock.c:2765 lock_sock include/net/sock.h:1467 [inline] pppol2tp_release+0x45/0x290 net/l2tp/l2tp_ppp.c:476 __sock_release+0xc2/0x2a0 net/socket.c:602 sock_close+0x10/0x20 net/socket.c:1139 __fput+0x232/0x750 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x16a/0x1b0 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413741 RSP: 002b:00007ffc593ca6b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000413741 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000000 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffc593ca790 R11: 0000000000000293 R12: 000000000075bfc8 R13: 000000000000ec1b R14: 0000000000760c10 R15: 000000000075bfd4 Allocated by task 11522: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15b/0x7b0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] sk_prot_alloc+0x146/0x240 net/core/sock.c:1467 sk_alloc+0x30/0xc10 net/core/sock.c:1521 pppol2tp_create+0x23/0x1d0 net/l2tp/l2tp_ppp.c:534 pppox_create+0xd3/0x1f0 drivers/net/ppp/pppox.c:134 __sock_create+0x262/0x540 net/socket.c:1275 sock_create net/socket.c:1315 [inline] SYSC_socket net/socket.c:1345 [inline] SyS_socket+0xc6/0x1a0 net/socket.c:1325 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 11522: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 sk_prot_free net/core/sock.c:1504 [inline] __sk_destruct+0x3e1/0x4e0 net/core/sock.c:1581 sk_destruct+0x83/0xb0 net/core/sock.c:1596 __sk_free+0x47/0x1f0 net/core/sock.c:1604 sk_free+0x23/0x30 net/core/sock.c:1615 sock_put include/net/sock.h:1658 [inline] pppol2tp_session_sock_put+0x4d/0x60 net/l2tp/l2tp_ppp.c:271 l2tp_tunnel_closeall+0x208/0x2f0 net/l2tp/l2tp_core.c:1348 l2tp_udp_encap_destroy+0x7d/0xc0 net/l2tp/l2tp_core.c:1371 udpv6_destroy_sock+0x89/0xb0 net/ipv6/udp.c:1444 sk_common_release+0x5e/0x2c0 net/core/sock.c:2992 udp_lib_close+0x9/0x10 include/net/udp.h:203 inet_release+0xd9/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x46/0x60 net/ipv6/af_inet6.c:450 __sock_release+0xc2/0x2a0 net/socket.c:602 sock_close+0x10/0x20 net/socket.c:1139 __fput+0x232/0x750 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x16a/0x1b0 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff888087f03500 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff888087f03500, ffff888087f03d00) The buggy address belongs to the page: page:ffffea00021fc080 count:1 mapcount:0 mapping:ffff888087f02400 index:0xffff888087f02400 compound_mapcount: 0 flags: 0x1fffc0000008100(slab|head) raw: 01fffc0000008100 ffff888087f02400 ffff888087f02400 0000000100000002 raw: ffffea0002863ea0 ffffea00022a8ea0 ffff8880aa800c40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888087f03480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888087f03500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888087f03580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888087f03600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888087f03680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================