netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. ================================================================== 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 ffff8801d61ab688 by task syz-executor2/9031 CPU: 1 PID: 9031 Comm: syz-executor2 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:__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:ffff8801c24b6f58 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 0000000000000006 RDX: 1ffffffff0b59305 RSI: 1ffff1003a64a9dd RDI: 0000000000000282 RBP: ffff8801c24b6f68 R08: ffff88021fffd6d8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88021fffd6c0 R13: ffff88021fffa000 R14: ffff88021fffd6c0 R15: ffffea00065c8000 spin_unlock_irqrestore include/linux/spinlock.h:371 [inline] deferred_split_huge_page+0x207/0x590 mm/huge_memory.c:2711 page_remove_rmap+0x767/0xcb0 mm/rmap.c:1315 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 unmap_region+0x2b9/0x4f0 mm/mmap.c:2496 do_munmap+0x726/0xdf0 mm/mmap.c:2709 mmap_region+0x59e/0x15a0 mm/mmap.c:1631 do_mmap+0x6a1/0xd50 mm/mmap.c:1468 do_mmap_pgoff include/linux/mm.h:2151 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1518 [inline] SyS_mmap_pgoff+0x23b/0x5f0 mm/mmap.c:1476 SYSC_mmap arch/x86/kernel/sys_x86_64.c:99 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:90 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x451e59 RSP: 002b:00007f68fb79cc08 EFLAGS: 00000216 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 0000000000451e59 RDX: 0000000000000003 RSI: 0000000000fff000 RDI: 0000000020000000 RBP: 0000000000000082 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000032 R11: 0000000000000216 R12: 00000000004bbaa2 R13: 00000000ffffffff R14: 00000000200b4000 R15: 0000000000000008 Allocated by task 8453: 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 8453: 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 ffff8801d61a8280 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 13320 bytes inside of 16384-byte region [ffff8801d61a8280, ffff8801d61ac280) The buggy address belongs to the page: page:ffffea0007586a00 count:1 mapcount:0 mapping:ffff8801d61a8280 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801d61a8280 0000000000000000 0000000100000001 raw: ffffea00074a3020 ffffea0007316820 ffff8801dac02200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d61ab580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d61ab600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d61ab680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d61ab700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d61ab780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================