From: syzbot <syzbot+5248ff94d8e3548ee995@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, aryabinin@virtuozzo.com, guro@fb.com,
hannes@cmpxchg.org, jbacik@fb.com, ktkhai@virtuozzo.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
mhocko@suse.com, minchan@kernel.org,
penguin-kernel@I-love.SAKURA.ne.jp, rientjes@google.com,
sfr@canb.auug.org.au, shakeelb@google.com,
syzkaller-bugs@googlegroups.com, ying.huang@intel.com
Subject: KASAN: slab-out-of-bounds Read in find_first_bit
Date: Fri, 06 Jul 2018 15:39:03 -0700 [thread overview]
Message-ID: <000000000000af3c0305705c5425@google.com> (raw)
Hello,
syzbot found the following crash on:
HEAD commit: 526674536360 Add linux-next specific files for 20180706
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13e6a50c400000
kernel config: https://syzkaller.appspot.com/x/.config?x=c8d1cfc0cb798e48
dashboard link: https://syzkaller.appspot.com/bug?extid=5248ff94d8e3548ee995
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=13a08a78400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17a08a78400000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5248ff94d8e3548ee995@syzkaller.appspotmail.com
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100
lib/find_bit.c:107
Read of size 8 at addr ffff8801d7548d50 by task syz-executor441/4505
CPU: 1 PID: 4505 Comm: syz-executor441 Not tainted
4.18.0-rc3-next-20180706+ #1
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+0x1c9/0x2b4 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
find_first_bit+0xf7/0x100 lib/find_bit.c:107
shrink_slab_memcg mm/vmscan.c:580 [inline]
shrink_slab+0x5d0/0xdb0 mm/vmscan.c:672
shrink_node+0x429/0x16a0 mm/vmscan.c:2736
shrink_zones mm/vmscan.c:2965 [inline]
do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3027
try_to_free_mem_cgroup_pages+0x49d/0xc90 mm/vmscan.c:3325
memory_high_write+0x283/0x310 mm/memcontrol.c:5597
cgroup_file_write+0x31f/0x840 kernel/cgroup/cgroup.c:3500
kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316
__vfs_write+0x117/0x9f0 fs/read_write.c:485
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4419d9
Code: e8 ec b5 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 7b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcd44b9a78 EFLAGS: 00000217 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9
RDX: 000000000000006b RSI: 0000000020000740 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006
R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000
R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000
Allocated by task 4504:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
__do_kmalloc_node mm/slab.c:3682 [inline]
__kmalloc_node+0x47/0x70 mm/slab.c:3689
kmalloc_node include/linux/slab.h:555 [inline]
kvmalloc_node+0x65/0xf0 mm/util.c:423
kvmalloc include/linux/mm.h:557 [inline]
kvzalloc include/linux/mm.h:565 [inline]
memcg_alloc_shrinker_maps mm/memcontrol.c:386 [inline]
mem_cgroup_css_online+0x169/0x3c0 mm/memcontrol.c:4685
online_css+0x10c/0x350 kernel/cgroup/cgroup.c:4768
css_create kernel/cgroup/cgroup.c:4839 [inline]
cgroup_apply_control_enable+0x777/0xe90 kernel/cgroup/cgroup.c:2987
cgroup_mkdir+0x88a/0x1170 kernel/cgroup/cgroup.c:5029
kernfs_iop_mkdir+0x159/0x1e0 fs/kernfs/dir.c:1099
vfs_mkdir+0x42e/0x6b0 fs/namei.c:3874
do_mkdirat+0x27b/0x310 fs/namei.c:3897
__do_sys_mkdir fs/namei.c:3913 [inline]
__se_sys_mkdir fs/namei.c:3911 [inline]
__x64_sys_mkdir+0x5c/0x80 fs/namei.c:3911
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 2873:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kfree+0xd9/0x260 mm/slab.c:3813
single_release+0x8f/0xb0 fs/seq_file.c:596
__fput+0x35d/0x930 fs/file_table.c:215
____fput+0x15/0x20 fs/file_table.c:251
task_work_run+0x1ec/0x2a0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:192 [inline]
exit_to_usermode_loop+0x313/0x370 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8801d7548d40
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 16 bytes inside of
32-byte region [ffff8801d7548d40, ffff8801d7548d60)
The buggy address belongs to the page:
page:ffffea00075d5200 count:1 mapcount:0 mapping:ffff8801da8001c0
index:0xffff8801d7548fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea00075d5448 ffffea00075d3b08 ffff8801da8001c0
raw: ffff8801d7548fc1 ffff8801d7548000 0000000100000039 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8801d7548c00: 00 04 fc fc fc fc fc fc 00 03 fc fc fc fc fc fc
ffff8801d7548c80: 00 05 fc fc fc fc fc fc 00 03 fc fc fc fc fc fc
> ffff8801d7548d00: 00 07 fc fc fc fc fc fc 00 00 05 fc fc fc fc fc
^
ffff8801d7548d80: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc
ffff8801d7548e00: 00 00 00 fc fc fc fc fc 00 00 00 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.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
next reply other threads:[~2018-07-06 22:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-06 22:39 syzbot [this message]
2018-07-08 14:42 ` KASAN: slab-out-of-bounds Read in find_first_bit Kirill Tkhai
2018-07-08 14:42 ` Kirill Tkhai
2018-07-17 19:12 ` Eric Biggers
2018-07-17 19:12 ` Eric Biggers
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=000000000000af3c0305705c5425@google.com \
--to=syzbot+5248ff94d8e3548ee995@syzkaller.appspotmail.com \
--cc=akpm@linux-foundation.org \
--cc=aryabinin@virtuozzo.com \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=jbacik@fb.com \
--cc=ktkhai@virtuozzo.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=minchan@kernel.org \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=rientjes@google.com \
--cc=sfr@canb.auug.org.au \
--cc=shakeelb@google.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=ying.huang@intel.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.