BUG: KASAN: use-after-free in arch_local_irq_enable arch/x86/include/asm/paravirt.h:787 [inline]
BUG: KASAN: use-after-free in __do_page_fault+0xc03/0xd60 arch/x86/mm/fault.c:1351
Read of size 8 at addr ffff88006b8e1f00 by task syz-executor6/28517

CPU: 3 PID: 28517 Comm: syz-executor6 Not tainted 4.14.0-rc5-next-20171018+ #8
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 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_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 arch_local_irq_enable arch/x86/include/asm/paravirt.h:787 [inline]
 __do_page_fault+0xc03/0xd60 arch/x86/mm/fault.c:1351
 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1514
 do_async_page_fault+0x82/0x110 arch/x86/kernel/kvm.c:273
 async_page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1069
RIP: 0033:0x43164f
RSP: 002b:00007f916f039790 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00007f916f0397c0 RCX: 00007f916f0397bf
RDX: 0000000000000400 RSI: 0000000020012fee RDI: 00007f916f0397c0
RBP: 0000000000748020 R08: 0000000000000000 R09: 0000000000000100
R10: 0000000020012fee R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000008430 R14: 00000000006ec4d0 R15: 00007f916f03a700

Allocated by task 28517:
 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
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3548
 kmem_cache_zalloc include/linux/slab.h:681 [inline]
 mmap_region+0x7ee/0x15a0 mm/mmap.c:1658
 do_mmap+0x69b/0xd40 mm/mmap.c:1468
 do_mmap_pgoff include/linux/mm.h:2199 [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

Freed by task 28540:
 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:3492 [inline]
 kmem_cache_free+0x77/0x280 mm/slab.c:3750
 remove_vma+0x162/0x1b0 mm/mmap.c:176
 remove_vma_list mm/mmap.c:2475 [inline]
 do_munmap+0x82a/0xdf0 mm/mmap.c:2714
 mmap_region+0x59e/0x15a0 mm/mmap.c:1631
 do_mmap+0x69b/0xd40 mm/mmap.c:1468
 do_mmap_pgoff include/linux/mm.h:2199 [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

The buggy address belongs to the object at ffff88006b8e1eb0
 which belongs to the cache vm_area_struct of size 200
The buggy address is located 80 bytes inside of
 200-byte region [ffff88006b8e1eb0, ffff88006b8e1f78)
The buggy address belongs to the page:
page:ffffea0001ae3840 count:1 mapcount:0 mapping:ffff88006b8e1040 index:0xffff88006b8e1148
flags: 0x500000000000100(slab)
raw: 0500000000000100 ffff88006b8e1040 ffff88006b8e1148 0000000100000007
raw: ffffea0001a0e7e0 ffffea0001ab25a0 ffff88003e87b500 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88006b8e1e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
 ffff88006b8e1e80: fc fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb
>ffff88006b8e1f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
                   ^
 ffff88006b8e1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88006b8e2000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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