================================================================== 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 ffff8801d0284148 by task syz-executor7/3078 CPU: 1 PID: 3078 Comm: syz-executor7 Not tainted 4.14.0-rc2-next-20170929+ #32 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+0x25b/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+0x29d/0xbb2 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:540 [inline] smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1041 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:770 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:787 [inline] RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] RIP: 0010:_raw_spin_unlock_irq+0x56/0x70 kernel/locking/spinlock.c:199 RSP: 0018:ffff88019a90f7f8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff11 RAX: dffffc0000000000 RBX: ffff8801db325dc0 RCX: 0000000000000000 RDX: 1ffffffff0b5970f RSI: 0000000000000001 RDI: ffffffff85acb878 RBP: ffff88019a90f800 R08: ffff8801db325dd8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801cb4cc400 R13: 1ffff10033521f08 R14: ffff8801cbbc2340 R15: ffff8801cbbc2340 finish_lock_switch kernel/sched/sched.h:1335 [inline] finish_task_switch+0x1d3/0x740 kernel/sched/core.c:2656 context_switch kernel/sched/core.c:2798 [inline] __schedule+0x8f0/0x2070 kernel/sched/core.c:3374 schedule+0xf5/0x430 kernel/sched/core.c:3433 freezable_schedule include/linux/freezer.h:171 [inline] do_nanosleep+0x224/0x6e0 kernel/time/hrtimer.c:1473 hrtimer_nanosleep+0x2b2/0x860 kernel/time/hrtimer.c:1527 SYSC_nanosleep kernel/time/hrtimer.c:1559 [inline] SyS_nanosleep+0x175/0x1f0 kernel/time/hrtimer.c:1546 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x47d6f0 RSP: 002b:0000000000a6f9e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 000000000169f914 RCX: 000000000047d6f0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000a6f9f0 RBP: 0000000000000086 R08: 0000000000000001 R09: 000000000169f940 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000cd R13: 000000000000001e R14: 000000000000a994 R15: 0000000000000010 Allocated by task 4740: 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:3690 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3697 kmalloc_node include/linux/slab.h:550 [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+0x16d/0xed0 net/core/dev.c:8044 tun_set_iff drivers/net/tun.c:2245 [inline] __tun_chr_ioctl+0x1386/0x3e40 drivers/net/tun.c:2499 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2744 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 4740: 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:3504 [inline] kfree+0xca/0x250 mm/slab.c:3821 kvfree+0x36/0x60 mm/util.c:416 netdev_freemem net/core/dev.c:7996 [inline] free_netdev+0x2cf/0x360 net/core/dev.c:8158 tun_set_iff drivers/net/tun.c:2328 [inline] __tun_chr_ioctl+0x2df6/0x3e40 drivers/net/tun.c:2499 tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:2744 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 ffff8801d0280d40 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 13320 bytes inside of 16384-byte region [ffff8801d0280d40, ffff8801d0284d40) The buggy address belongs to the page: page:ffffea000740a000 count:1 mapcount:0 mapping:ffff8801d0280d40 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801d0280d40 0000000000000000 0000000100000001 raw: ffffea0007428e20 ffffea0007433420 ffff8801dac02200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d0284000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d0284080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d0284100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d0284180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d0284200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================