================================================================== 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 ffff8801cb084788 by task syz-executor1/11556 CPU: 1 PID: 11556 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:ffff8801d9257a68 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 0000000000000000 RDX: 1ffffffff0b59335 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffff8801d9257a78 R08: 1ffff1003b1815c4 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d8c0ade0 R13: ffff8801d9257d88 R14: ffff8801d9257d90 R15: ffff8801d8c0ade0 spin_unlock_irqrestore include/linux/spinlock.h:371 [inline] remove_wait_queue+0x1b4/0x350 kernel/sched/wait.c:52 do_wait+0x50a/0xa90 kernel/exit.c:1546 kernel_wait4+0x1f5/0x370 kernel/exit.c:1664 SYSC_wait4+0x134/0x140 kernel/exit.c:1676 SyS_wait4+0x2c/0x40 kernel/exit.c:1672 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x40c4aa RSP: 002b:0000000000a6fa08 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 0000000001c8e914 RCX: 000000000040c4aa RDX: 0000000040000001 RSI: 0000000000a6fa2c RDI: ffffffffffffffff RBP: 0000000000000082 R08: 0000000000000001 R09: 0000000001c8e940 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000004ec R13: 000000000000001e R14: 0000000000036c5b R15: 0000000000000010 Allocated by task 22496: 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 22496: 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 ffff8801cb081380 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 13320 bytes inside of 16384-byte region [ffff8801cb081380, ffff8801cb085380) The buggy address belongs to the page: page:ffffea00072c2000 count:1 mapcount:0 mapping:ffff8801cb081380 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801cb081380 0000000000000000 0000000100000001 raw: ffffea0007060c20 ffff8801dac01c50 ffff8801dac02200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cb084680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cb084700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801cb084780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cb084800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cb084880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================