l2tp_core: tunl 4: sockfd_lookup(fd=3) returned -9 l2tp_core: tunl 4: sockfd_lookup(fd=3) returned -9 ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3098/0x4620 kernel/locking/lockdep.c:3365 Read of size 8 at addr ffff88807d136a20 by task syz-executor.0/21839 CPU: 0 PID: 21839 Comm: syz-executor.0 Not tainted 4.14.160-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+0x142/0x197 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 __lock_acquire+0x3098/0x4620 kernel/locking/lockdep.c:3365 lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:176 spin_lock_bh include/linux/spinlock.h:322 [inline] lock_sock_nested+0x3f/0x110 net/core/sock.c:2762 lock_sock include/net/sock.h:1462 [inline] pppol2tp_release+0x4e/0x310 net/l2tp/l2tp_ppp.c:476 __sock_release+0xce/0x2b0 net/socket.c:602 sock_close+0x1b/0x30 net/socket.c:1139 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 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+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4144b1 RSP: 002b:00007ffda5c5d320 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00000000004144b1 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000004 RBP: 0000000000000000 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffda5c5d400 R11: 0000000000000293 R12: 000000000075bfc8 R13: 00000000001470c9 R14: 0000000000760858 R15: 000000000075bfd4 Allocated by task 21844: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15d/0x7a0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] sk_prot_alloc+0x171/0x2a0 net/core/sock.c:1467 sk_alloc+0x39/0xd70 net/core/sock.c:1521 pppol2tp_create+0x32/0x1f0 net/l2tp/l2tp_ppp.c:534 pppox_create+0xf7/0x210 drivers/net/ppp/pppox.c:134 __sock_create+0x2f6/0x620 net/socket.c:1275 sock_create net/socket.c:1315 [inline] SYSC_socket net/socket.c:1345 [inline] SyS_socket+0xd3/0x170 net/socket.c:1325 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 21839: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 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+0x50f/0x650 net/core/sock.c:1581 sk_destruct+0xa4/0xd0 net/core/sock.c:1596 __sk_free+0x54/0x230 net/core/sock.c:1604 sk_free+0x35/0x40 net/core/sock.c:1615 sock_put include/net/sock.h:1653 [inline] pppol2tp_session_sock_put+0x66/0x80 net/l2tp/l2tp_ppp.c:271 l2tp_tunnel_closeall+0x27f/0x380 net/l2tp/l2tp_core.c:1343 l2tp_udp_encap_destroy+0x96/0x100 net/l2tp/l2tp_core.c:1366 udpv6_destroy_sock+0xb3/0xd0 net/ipv6/udp.c:1444 sk_common_release+0x6b/0x310 net/core/sock.c:2989 udp_lib_close+0x16/0x20 include/net/udp.h:203 inet_release+0xec/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:450 __sock_release+0xce/0x2b0 net/socket.c:602 sock_close+0x1b/0x30 net/socket.c:1139 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 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+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff88807d136980 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff88807d136980, ffff88807d137180) The buggy address belongs to the page: page:ffffea0001f44d80 count:1 mapcount:0 mapping:ffff88807d136100 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffff88807d136100 0000000000000000 0000000100000003 raw: ffffea000271c320 ffffea00026fd8a0 ffff8880aa800c40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88807d136900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807d136980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d136a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d136a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d136b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================