All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+903b72a010ad6b7a40f2@syzkaller.appspotmail.com>
To: axboe@kernel.dk, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, rostedt@goodmis.org,
	syzkaller-bugs@googlegroups.com
Subject: KASAN: use-after-free Read in debugfs_remove (3)
Date: Wed, 10 Oct 2018 01:09:03 -0700	[thread overview]
Message-ID: <000000000000140c370577db5ece@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    0854ba5ff5c9 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=148516a1400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d
dashboard link: https://syzkaller.appspot.com/bug?extid=903b72a010ad6b7a40f2
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+903b72a010ad6b7a40f2@syzkaller.appspotmail.com

QAT: Invalid ioctl
==================================================================
BUG: KASAN: use-after-free in debugfs_remove+0x10b/0x130  
fs/debugfs/inode.c:682
Read of size 8 at addr ffff880173458460 by task syz-executor0/8436

CPU: 1 PID: 8436 Comm: syz-executor0 Not tainted 4.19.0-rc7+ #274
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
  print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  debugfs_remove+0x10b/0x130 fs/debugfs/inode.c:682
  blk_trace_free+0x35/0x130 kernel/trace/blktrace.c:312
  blk_trace_cleanup kernel/trace/blktrace.c:339 [inline]
  __blk_trace_remove+0x7a/0xa0 kernel/trace/blktrace.c:352
  blk_trace_ioctl+0x243/0x2f0 kernel/trace/blktrace.c:730
  blkdev_ioctl+0x8bc/0x2010 block/ioctl.c:587
  block_ioctl+0xee/0x130 fs/block_dev.c:1883
  vfs_ioctl fs/ioctl.c:46 [inline]
  file_ioctl fs/ioctl.c:501 [inline]
  do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
  ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
  __do_sys_ioctl fs/ioctl.c:709 [inline]
  __se_sys_ioctl fs/ioctl.c:707 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
dccp_close: ABORT with 1061 bytes unread
Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f55a7fc7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
dccp_close: ABORT with 105978 bytes unread
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f55a7fc86d4
R13: 00000000004bea1e R14: 00000000004ce728 R15: 00000000ffffffff

Allocated by task 8444:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
  kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
  __d_alloc+0xc8/0xcc0 fs/dcache.c:1614
  d_alloc+0x96/0x380 fs/dcache.c:1698
  d_alloc_parallel+0x15a/0x1f40 fs/dcache.c:2441
  __lookup_slow+0x1e6/0x540 fs/namei.c:1654
  lookup_one_len+0x1d8/0x220 fs/namei.c:2543
  start_creating+0xc6/0x200 fs/debugfs/inode.c:308
  __debugfs_create_file+0x63/0x400 fs/debugfs/inode.c:347
  debugfs_create_file+0x57/0x70 fs/debugfs/inode.c:399
  do_blk_trace_setup+0x454/0xda0 kernel/trace/blktrace.c:528
  __blk_trace_setup+0xd5/0x180 kernel/trace/blktrace.c:577
  blk_trace_ioctl+0x17a/0x2f0 kernel/trace/blktrace.c:716
  blkdev_ioctl+0x8bc/0x2010 block/ioctl.c:587
  block_ioctl+0xee/0x130 fs/block_dev.c:1883
  vfs_ioctl fs/ioctl.c:46 [inline]
  file_ioctl fs/ioctl.c:501 [inline]
  do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
  ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
QAT: Invalid ioctl
  __do_sys_ioctl fs/ioctl.c:709 [inline]
  __se_sys_ioctl fs/ioctl.c:707 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8444:
QAT: Invalid ioctl
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
  kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
  __cache_free mm/slab.c:3498 [inline]
  kmem_cache_free+0x83/0x290 mm/slab.c:3756
  __d_free+0x20/0x30 fs/dcache.c:257
  __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
  rcu_do_batch kernel/rcu/tree.c:2576 [inline]
  invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline]
  __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline]
  rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864
  __do_softirq+0x30b/0xad8 kernel/softirq.c:292

The buggy address belongs to the object at ffff880173458420
  which belongs to the cache dentry(17:syz0) of size 288
The buggy address is located 64 bytes inside of
  288-byte region [ffff880173458420, ffff880173458540)
The buggy address belongs to the page:
page:ffffea0005cd1600 count:1 mapcount:0 mapping:ffff8801ca231c80 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0005d3fec8 ffff8801ce0f5848 ffff8801ca231c80
raw: 0000000000000000 ffff880173458000 000000010000000b ffff880186fa62c0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff880186fa62c0
QAT: Invalid ioctl

Memory state around the buggy address:
  ffff880173458300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff880173458380: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
> ffff880173458400: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb
                                                        ^
  ffff880173458480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff880173458500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with  
syzbot.

             reply	other threads:[~2018-10-10  8:09 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-10  8:09 syzbot [this message]
2018-10-20 16:32 ` KASAN: use-after-free Read in debugfs_remove (3) syzbot
2018-12-02  2:13 ` syzbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=000000000000140c370577db5ece@google.com \
    --to=syzbot+903b72a010ad6b7a40f2@syzkaller.appspotmail.com \
    --cc=axboe@kernel.dk \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rostedt@goodmis.org \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.