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BUG: KASAN: slab-out-of-bounds in cap_convert_nscap+0x501/0x610 security/commoncap.c:498
Read of size 4 at addr ffff8801d2ef1c40 by task syz-executor1/13720

CPU: 1 PID: 13720 Comm: syz-executor1 Not tainted 4.15.0-rc4-next-20171221+ #78
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 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_load4_noabort+0x14/0x20 mm/kasan/report.c:429
 cap_convert_nscap+0x501/0x610 security/commoncap.c:498
 setxattr+0x365/0x400 fs/xattr.c:446
 SYSC_fsetxattr fs/xattr.c:508 [inline]
 SyS_fsetxattr+0x130/0x190 fs/xattr.c:497
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452ac9
RSP: 002b:00007f1c60e32c58 EFLAGS: 00000212 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 000000002047a000 RSI: 0000000020000000 RDI: 0000000000000013
RBP: 0000000000000578 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000212 R12: 00000000006f63e0
R13: 00000000ffffffff R14: 00007f1c60e336d4 R15: 0000000000000000

Allocated by task 13720:
 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:3673 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3680
 kmalloc_node include/linux/slab.h:558 [inline]
 kvmalloc_node+0x99/0xd0 mm/util.c:397
 kvmalloc include/linux/mm.h:541 [inline]
 setxattr+0x152/0x400 fs/xattr.c:435
 SYSC_fsetxattr fs/xattr.c:508 [inline]
 SyS_fsetxattr+0x130/0x190 fs/xattr.c:497
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 10529:
 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:3489 [inline]
 kfree+0xd6/0x260 mm/slab.c:3804
 kvm_destroy_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:559 [inline]
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:709 [inline]
 kvm_put_kvm+0x28e/0xde0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:749
 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:760
 __fput+0x327/0x7e0 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x199/0x270 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
 entry_SYSCALL_64_fastpath+0x94/0x96

The buggy address belongs to the object at ffff8801d2ef1c40
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d2ef1c40, ffff8801d2ef1c60)
The buggy address belongs to the page:
page:000000002203a6ee count:1 mapcount:0 mapping:0000000013dec33a index:0xffff8801d2ef1fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d2ef1000 ffff8801d2ef1fc1 000000010000003e
raw: ffffea000748f060 ffffea00074a9a20 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d2ef1b00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d2ef1b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d2ef1c00: fb fb fb fb fc fc fc fc 03 fc fc fc fc fc fc fc
                                           ^
 ffff8801d2ef1c80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d2ef1d00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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