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: 0 PID: 8 Comm: ksoftirqd/0 Not tainted 4.13.0-next-20170906+ #16 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003e004200 task.stack: ffff88003e008000 RIP: 0010:__hlist_del include/linux/list.h:650 [inline] RIP: 0010:detach_timer kernel/time/timer.c:791 [inline] RIP: 0010:expire_timers kernel/time/timer.c:1309 [inline] RIP: 0010:__run_timers+0x619/0xb90 kernel/time/timer.c:1620 RSP: 0018:ffff88003e00f920 EFLAGS: 00010806 RAX: 1bd5a00000000041 RBX: ffff880039933980 RCX: 1ffff10007c01f6d RDX: ffff88003e00fb68 RSI: 0000000000000008 RDI: dead000000000208 RBP: ffff88003e00fc10 R08: ffff88003e00f270 R09: ffff88003e00f268 R10: ffff88003e00f1e0 R11: 1ffff10007c00ad3 R12: ffff880039933988 R13: dffffc0000000000 R14: dead000000000200 R15: ffff88003e00fbe8 FS: 0000000000000000(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020f9f000 CR3: 0000000037831000 CR4: 00000000000006f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000020001008 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1646 __do_softirq+0x2bb/0xbd0 kernel/softirq.c:284 run_ksoftirqd+0x50/0x100 kernel/softirq.c:676 smpboot_thread_fn+0x489/0x850 kernel/smpboot.c:164 kthread+0x39c/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Code: 4d 85 f6 4c 89 32 48 89 95 58 fd ff ff 42 c6 04 28 f8 74 26 e8 79 36 10 00 49 8d 7e 08 48 8b 95 58 fd ff ff 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 0f 85 b5 04 00 00 49 89 56 08 e8 53 36 10 00 4c RIP: __hlist_del include/linux/list.h:650 [inline] RSP: ffff88003e00f920 RIP: detach_timer kernel/time/timer.c:791 [inline] RSP: ffff88003e00f920 RIP: expire_timers kernel/time/timer.c:1309 [inline] RSP: ffff88003e00f920 RIP: __run_timers+0x619/0xb90 kernel/time/timer.c:1620 RSP: ffff88003e00f920 ---[ end trace 110246f2f378159c ]--- Kernel panic - not syncing: Fatal exception in interrupt BUG: KASAN: use-after-free in __collect_expired_timers include/linux/list.h:729 [inline] BUG: KASAN: use-after-free in collect_expired_timers kernel/time/timer.c:1569 [inline] BUG: KASAN: use-after-free in __run_timers+0xa2e/0xb90 kernel/time/timer.c:1616 Write of size 8 at addr ffff88003a3f3a88 by task syz-executor7/6457 CPU: 1 PID: 6457 Comm: syz-executor7 Tainted: G D 4.13.0-next-20170906+ #16 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:435 __collect_expired_timers include/linux/list.h:729 [inline] collect_expired_timers kernel/time/timer.c:1569 [inline] __run_timers+0xa2e/0xb90 kernel/time/timer.c:1616 run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1646 __do_softirq+0x2bb/0xbd0 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1d3/0x210 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x177/0x710 arch/x86/kernel/apic/apic.c:1048 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:577 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:814 [inline] RIP: 0010:lock_release+0x69b/0xd70 kernel/locking/lockdep.c:4024 RSP: 0018:ffff880054ce6798 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 1ffff1000a99ccf8 RCX: ffff880057846a38 RDX: 1ffffffff0b59305 RSI: 0000000000000002 RDI: 0000000000000282 RBP: ffff880054ce6948 R08: ffff88003ed1f340 R09: 1ffff1000a99cd04 R10: ffff880057846140 R11: 0000000000000001 R12: ffff880054ce6820 R13: ffff880057846140 R14: 11dd6d1abf01f430 R15: 0000000000000003 rcu_lock_release include/linux/rcupdate.h:249 [inline] rcu_read_unlock include/linux/rcupdate.h:686 [inline] __unlock_page_memcg+0x72/0x100 mm/memcontrol.c:1697 unlock_page_memcg+0x2c/0x40 mm/memcontrol.c:1706 page_remove_file_rmap mm/rmap.c:1244 [inline] page_remove_rmap+0x3b7/0xcb0 mm/rmap.c:1295 zap_pte_range mm/memory.c:1333 [inline] zap_pmd_range mm/memory.c:1437 [inline] zap_pud_range mm/memory.c:1466 [inline] zap_p4d_range mm/memory.c:1487 [inline] unmap_page_range+0xf8d/0x22f0 mm/memory.c:1508 unmap_single_vma+0x15f/0x2d0 mm/memory.c:1553 unmap_vmas+0xf1/0x1b0 mm/memory.c:1583 exit_mmap+0x232/0x530 mm/mmap.c:3003 __mmput kernel/fork.c:924 [inline] mmput+0x223/0x6d0 kernel/fork.c:945 exit_mm kernel/exit.c:544 [inline] do_exit+0x9a1/0x1b40 kernel/exit.c:852 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:00007f7eb8fd8cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 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: 00007f7eb8fd99c0 R15: 00007f7eb8fd9700 Allocated by task 6039: 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+0xad/0xe0 mm/kasan/kasan.c:551 __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:535 [inline] kvmalloc_node+0x64/0xd0 mm/util.c:397 kvmalloc include/linux/mm.h:529 [inline] kvzalloc include/linux/mm.h:537 [inline] alloc_netdev_mqs+0x16e/0xed0 net/core/dev.c:8011 tun_set_iff drivers/net/tun.c:2022 [inline] __tun_chr_ioctl+0x12be/0x3d20 drivers/net/tun.c:2276 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2521 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 6072: 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:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 kvfree+0x36/0x60 mm/util.c:416 netdev_freemem+0x4c/0x60 net/core/dev.c:7963 netdev_release+0x76/0x90 net/core/net-sysfs.c:1492 device_release+0x7c/0x200 drivers/base/core.c:814 kobject_cleanup lib/kobject.c:648 [inline] kobject_release lib/kobject.c:677 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put+0x14c/0x240 lib/kobject.c:694 netdev_run_todo+0x914/0xca0 net/core/dev.c:7868 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:246 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 The buggy address belongs to the object at ffff88003a3f0680 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 13320 bytes inside of 16384-byte region [ffff88003a3f0680, ffff88003a3f4680) The buggy address belongs to the page: page:ffffea0000e8fc00 count:1 mapcount:0 mapping:ffff88003a3f0680 index:0x0 compound_mapcount: 0 flags: 0x100000000008100(slab|head) raw: 0100000000008100 ffff88003a3f0680 0000000000000000 0000000100000001 raw: ffffea0000e64c20 ffffea0000f52e20 ffff88003e802200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88003a3f3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88003a3f3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88003a3f3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88003a3f3b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88003a3f3b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Shutting down cpus with NMI Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..