Message-ID: <94eb2c0433c8f42cac055cc86991@google.com>
Date:   Mon, 30 Oct 2017 12:12:04 -0700
From:   syzbot 
        <bot+6a5269ce759a7bb12754ed9622076dc93f65a1f6@...kaller.appspotmail.com>
To:     JBeulich@...e.com, hpa@...or.com, jpoimboe@...hat.com,
        kirill.shutemov@...ux.intel.com, ldufour@...ux.vnet.ibm.com,
        linux-kernel@...r.kernel.org, luto@...nel.org, mingo@...hat.com,
        syzkaller-bugs@...glegroups.com, tglx@...utronix.de, x86@...nel.org
Subject: KASAN: use-after-free Read in __do_page_fault

Hello,

syzkaller hit the following crash on  
887c8ba753fbe809ba93fa3cfd0cc46db18d37d4
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.

syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers


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:1357
Read of size 8 at addr ffff8801cbfd3090 by task syz-executor7/3660

CPU: 1 PID: 3660 Comm: syz-executor7 Not tainted 4.14.0-rc3+ #23
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+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:1357
  do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1520
  page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1066
RIP: 0023:0x8073f4f
RSP: 002b:00000000f7f89bd0 EFLAGS: 00010202
RAX: 00000000f7f89c8c RBX: 0000000000000400 RCX: 000000000000000e
RDX: 00000000f7f8aa88 RSI: 0000000020012fe0 RDI: 00000000f7f89c8c
RBP: 0000000008128000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 3660:
  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
  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
  kmem_cache_alloc+0x12e/0x760 mm/slab.c:3561
  kmem_cache_zalloc include/linux/slab.h:656 [inline]
  mmap_region+0x7ee/0x15a0 mm/mmap.c:1658
  do_mmap+0x6a1/0xd50 mm/mmap.c:1468
  do_mmap_pgoff include/linux/mm.h:2150 [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
  do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline]
  do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124

Freed by task 3667:
  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]
  kmem_cache_free+0x77/0x280 mm/slab.c:3763
  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+0x6a1/0xd50 mm/mmap.c:1468
  do_mmap_pgoff include/linux/mm.h:2150 [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
  do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline]
  do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124

The buggy address belongs to the object at ffff8801cbfd3040
  which belongs to the cache vm_area_struct of size 200
The buggy address is located 80 bytes inside of
  200-byte region [ffff8801cbfd3040, ffff8801cbfd3108)
The buggy address belongs to the page:
page:ffffea00072ff4c0 count:1 mapcount:0 mapping:ffff8801cbfd3040 index:0x0
flags: 0x200000000000100(slab)
raw: 0200000000000100 ffff8801cbfd3040 0000000000000000 000000010000000f
raw: ffffea000730c7a0 ffffea00072ff7a0 ffff8801dae069c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801cbfd2f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff8801cbfd3000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
> ffff8801cbfd3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                          ^
  ffff8801cbfd3100: fb fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb
  ffff8801cbfd3180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to syzkaller@...glegroups.com.

syzbot will keep track of this bug report.
Once a fix for this bug is committed, please reply to this email with:
#syz fix: exact-commit-title
To mark this as a duplicate of another syzbot report, please reply with:
#syz dup: exact-subject-of-another-report
If it's a one-off invalid bug report, please reply with:
#syz invalid
Note: if the crash happens again, it will cause creation of a new bug  
report.

View attachment "config.txt" of type "text/plain" (123749 bytes)

Download attachment "raw.log" of type "application/octet-stream" (7160 bytes)

View attachment "repro.txt" of type "text/plain" (672 bytes)

Powered by blists - more mailing lists