All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+29093015c21333d1c46d@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, ebiggers@google.com,
	jrdr.linux@gmail.com, keescook@chromium.org,
	linux-kernel@vger.kernel.org, mawilcox@microsoft.com,
	rientjes@google.com, syzkaller-bugs@googlegroups.com,
	viro@zeniv.linux.org.uk
Subject: KASAN: use-after-free Read in relay_switch_subbuf
Date: Wed, 26 Sep 2018 00:41:03 -0700	[thread overview]
Message-ID: <0000000000002e4a260576c1589d@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    2dd68cc7fd8c Merge gitolite.kernel.org:/pub/scm/linux/kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=105fe676400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=22a62640793a83c9
dashboard link: https://syzkaller.appspot.com/bug?extid=29093015c21333d1c46d
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+29093015c21333d1c46d@syzkaller.appspotmail.com

8021q: adding VLAN 0 to HW filter on device team0
device team0 left promiscuous mode
device team_slave_0 left promiscuous mode
device team_slave_1 left promiscuous mode
==================================================================
BUG: KASAN: use-after-free in relay_switch_subbuf+0xa0e/0xa70  
kernel/relay.c:753
Read of size 8 at addr ffff8801b3c10778 by task kworker/0:3/5668

CPU: 0 PID: 5668 Comm: kworker/0:3 Not tainted 4.19.0-rc5+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events __blk_release_queue
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
  relay_switch_subbuf+0xa0e/0xa70 kernel/relay.c:753
  relay_flush+0x1c6/0x280 kernel/relay.c:881
  __blk_trace_startstop.isra.20+0x2ae/0x8c0 kernel/trace/blktrace.c:668
  blk_trace_shutdown+0x5b/0x80 kernel/trace/blktrace.c:751
  __blk_release_queue+0x22d/0x500 block/blk-sysfs.c:852
  process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153
device team0 entered promiscuous mode
  worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
device team_slave_0 entered promiscuous mode
device team_slave_1 entered promiscuous mode
  kthread+0x35a/0x420 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413

Allocated by task 26646:
  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
8021q: adding VLAN 0 to HW filter on device team0
  __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+0xf2/0x220 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
  blk_create_buf_file_callback+0x33/0x40 kernel/trace/blktrace.c:444
  relay_create_buf_file+0xf6/0x150 kernel/relay.c:428
  relay_open_buf.part.10+0x753/0xb20 kernel/relay.c:455
  relay_open_buf kernel/relay.c:447 [inline]
  relay_open+0x5e9/0xac0 kernel/relay.c:597
  do_blk_trace_setup+0x4fb/0xda0 kernel/trace/blktrace.c:532
  __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
  __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 26604:
  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 ffff8801b3c10720
  which belongs to the cache dentry(81:syz1) of size 288
The buggy address is located 88 bytes inside of
  288-byte region [ffff8801b3c10720, ffff8801b3c10840)
The buggy address belongs to the page:
page:ffffea0006cf0400 count:1 mapcount:0 mapping:ffff8801bb6ce300 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea00072adb88 ffffea0006800c48 ffff8801bb6ce300
raw: 0000000000000000 ffff8801b3c10040 000000010000000b ffff8801c7eb6100
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8801c7eb6100

Memory state around the buggy address:
  ffff8801b3c10600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801b3c10680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
> ffff8801b3c10700: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb
                                                                 ^
  ffff8801b3c10780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801b3c10800: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
kobject: 'loop1' (00000000f4503744): kobject_uevent_env
device team0 left promiscuous mode
kobject: 'loop1' (00000000f4503744): fill_kobj_path: path  
= '/devices/virtual/block/loop1'
device team_slave_0 left promiscuous mode
kobject: 'cpu0' (000000004fdcedbb): kobject_add_internal: parent: '0',  
set: '<NULL>'
device team_slave_1 left promiscuous mode
kobject: 'cpu1' (00000000e70df734): kobject_add_internal: parent: '0',  
set: '<NULL>'
kobject: 'kvm' (000000009a7db5f0): kobject_uevent_env
kobject: 'queue' (0000000084fcdfca): kobject_uevent_env
kobject: 'kvm' (000000009a7db5f0): fill_kobj_path: path  
= '/devices/virtual/misc/kvm'
kobject: 'queue' (0000000084fcdfca): kobject_uevent_env: filter function  
caused the event to drop!
device team0 entered promiscuous mode


---
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:[~2018-09-26  7:41 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-26  7:41 syzbot [this message]
2019-11-06  7:58 ` KASAN: use-after-free Read in relay_switch_subbuf syzbot
2019-11-18  6:59 ` 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=0000000000002e4a260576c1589d@google.com \
    --to=syzbot+29093015c21333d1c46d@syzkaller.appspotmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=ebiggers@google.com \
    --cc=jrdr.linux@gmail.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mawilcox@microsoft.com \
    --cc=rientjes@google.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=viro@zeniv.linux.org.uk \
    /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.