kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 6206 Comm: syz-executor0 Not tainted 4.13.0-next-20170913+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88006925e180 task.stack: ffff88006a8f0000 RIP: 0010:__hlist_del include/linux/list.h:650 [inline] RIP: 0010:detach_timer kernel/time/timer.c:791 [inline] RIP: 0010:detach_if_pending+0x1ce/0x610 kernel/time/timer.c:808 RSP: 0018:ffff88006a8f6b70 EFLAGS: 00010806 RAX: 1bd5a00000000041 RBX: ffff8800324a3a80 RCX: dffffc0000000000 RDX: ffff88003ed1b440 RSI: 1ffff10007da3688 RDI: dead000000000208 RBP: ffff88006a8f6c90 R08: ffff88006a8f6528 R09: ffff88006a8f6520 R10: ffff88006a8f6498 R11: 1ffff1000d24bec3 R12: 1ffff1000d51ed71 R13: ffff8800324a3a88 R14: dffffc0000000000 R15: dead000000000200 FS: 00007ff140c6d700(0000) GS:ffff88003ed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdfbca3bfc CR3: 000000003d84a000 CR4: 00000000000026e0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: try_to_del_timer_sync+0xa2/0x120 kernel/time/timer.c:1182 del_timer_sync+0x18a/0x240 kernel/time/timer.c:1247 tun_flow_uninit drivers/net/tun.c:1104 [inline] tun_free_netdev+0x105/0x1b0 drivers/net/tun.c:1776 netdev_run_todo+0x870/0xca0 net/core/dev.c:7864 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:106 tun_detach drivers/net/tun.c:588 [inline] tun_chr_close+0x49/0x60 drivers/net/tun.c:2609 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:112 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0xa52/0x1b40 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x7e8/0x17e0 kernel/signal.c:2334 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808 exit_to_usermode_loop+0x224/0x300 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath+0x42f/0x500 arch/x86/entry/common.c:266 entry_SYSCALL_64_fastpath+0xbc/0xbe RIP: 0033:0x447299 RSP: 002b:00007ff140c6ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 0000000000708028 RCX: 0000000000447299 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000708028 RBP: 0000000000708000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff140c6d9c0 R15: 00007ff140c6d700 Code: 4d 85 ff 4c 89 3a 48 89 95 e8 fe ff ff 42 c6 04 30 f8 74 26 e8 84 51 10 00 49 8d 7f 08 48 8b 95 e8 fe ff ff 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 0f 85 91 03 00 00 49 89 57 08 e8 5e 51 10 00 80 RIP: __hlist_del include/linux/list.h:650 [inline] RSP: ffff88006a8f6b70 RIP: detach_timer kernel/time/timer.c:791 [inline] RSP: ffff88006a8f6b70 RIP: detach_if_pending+0x1ce/0x610 kernel/time/timer.c:808 RSP: ffff88006a8f6b70 ---[ end trace 7661013600d589f5 ]---