================================================================== 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 ffff8801ce454188 by task syz-executor4/12539 CPU: 0 PID: 12539 Comm: syz-executor4 Not tainted 4.13.0-next-20170908+ #18 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:814 [inline] RIP: 0010:kmem_cache_free+0x170/0x280 mm/slab.c:3764 RSP: 0000:ffff8801c807f0d8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000007 RBX: ffff8801ca64f000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffff8801c807f0f8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801dae069c0 R13: 0000000000000282 R14: ffffffff819836d2 R15: 0000000000000e83 remove_vma+0x162/0x1b0 mm/mmap.c:176 exit_mmap+0x33f/0x530 mm/mmap.c:3032 __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: 0033:0x451e59 RSP: 002b:00007ff3346d2cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00000000007182e8 RCX: 0000000000451e59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000007182e8 RBP: 00000000007182c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000a6f7ef R14: 00007ff3346d39c0 R15: 0000000000000014 Allocated by task 12042: 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 12042: 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:7963 [inline] free_netdev+0x2cf/0x360 net/core/dev.c:8125 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 ffff8801ce450d80 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 13320 bytes inside of 16384-byte region [ffff8801ce450d80, ffff8801ce454d80) The buggy address belongs to the page: page:ffffea0007391400 count:1 mapcount:0 mapping:ffff8801ce450d80 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801ce450d80 0000000000000000 0000000100000001 raw: ffffea00073d3c20 ffffea0007625a20 ffff8801dac02200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801ce454080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ce454100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801ce454180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801ce454200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ce454280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================