================================================================== BUG: KASAN: use-after-free in hlist_move_list include/linux/list.h:729 [inline] BUG: KASAN: use-after-free in __collect_expired_timers kernel/time/timer.c:1339 [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 ffff8801d8814ac8 by task syz-executor1/9863 CPU: 0 PID: 9863 Comm: syz-executor1 Not tainted 4.14.0-rc1+ #92 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 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 hlist_move_list include/linux/list.h:729 [inline] __collect_expired_timers kernel/time/timer.c:1339 [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:770 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:777 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x5e/0xba kernel/locking/spinlock.c:191 RSP: 0018:ffff8801cacd7230 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 0000000000000006 RDX: 1ffffffff0b59335 RSI: 1ffff100386f4557 RDI: 0000000000000282 RBP: ffff8801cacd7240 R08: ffffffff86094518 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff86094500 R13: 0000000000000001 R14: 0000000000000282 R15: ffff8801cacd7330 spin_unlock_irqrestore include/linux/spinlock.h:371 [inline] __wake_up_common_lock+0x1c2/0x310 kernel/sched/wait.c:126 __wake_up+0xe/0x10 kernel/sched/wait.c:149 netlink_unlock_table net/netlink/af_netlink.c:439 [inline] netlink_broadcast_filtered+0x5f6/0x1360 net/netlink/af_netlink.c:1477 kobject_uevent_env+0x6c9/0xb00 lib/kobject_uevent.c:459 kvm_uevent_notify_change.part.38+0x394/0x430 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3888 kvm_uevent_notify_change arch/x86/kvm/../../../virt/kvm/kvm_main.c:3847 [inline] kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:707 [inline] kvm_put_kvm+0x181/0xdf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:748 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:759 __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 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x4520a9 RSP: 002b:0000000000a6f9e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00000000010da914 RCX: 00000000004520a9 RDX: 00000000004520a9 RSI: 0000000000763430 RDI: 0000000000000000 RBP: 0000000000000082 R08: 00000000007180b0 R09: 0000000000000fe1 R10: 0000000000763428 R11: 0000000000000206 R12: fffffffffffffffe R13: 0000000000718210 R14: 0000000020afe000 R15: 0000000000000010 Allocated by task 9298: 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:8018 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 9298: 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 net/core/dev.c:7970 [inline] free_netdev+0x2cf/0x360 net/core/dev.c:8132 tun_set_iff drivers/net/tun.c:2105 [inline] __tun_chr_ioctl+0x2cf6/0x3d20 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 The buggy address belongs to the object at ffff8801d88116c0 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 13320 bytes inside of 16384-byte region [ffff8801d88116c0, ffff8801d88156c0) The buggy address belongs to the page: page:ffffea0007620400 count:1 mapcount:0 mapping:ffff8801d88116c0 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801d88116c0 0000000000000000 0000000100000001 raw: ffffea000675a420 ffffea000668c620 ffff8801dac02200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d8814980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d8814a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d8814a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d8814b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d8814b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================