From: syzbot <syzbot+76a43f2b4d34cfc53548@syzkaller.appspotmail.com>
To: akpm@osdl.org, deepa.kernel@gmail.com, hch@infradead.org,
jlayton@kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, lkundrak@v3.sk,
syzkaller-bugs@googlegroups.com, tklauser@nuerscht.ch,
trond.myklebust@fys.uio.no, viro@zeniv.linux.org.uk
Subject: KASAN: use-after-free Read in mnt_warn_timestamp_expiry
Date: Wed, 16 Oct 2019 18:42:11 -0700 [thread overview]
Message-ID: <0000000000007f489b0595115374@google.com> (raw)
Hello,
syzbot found the following crash on:
HEAD commit: 3b1f00ac Merge tag 'for_linus' of git://git.kernel.org/pub..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=137ae2bb600000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0a8b0a0736a2ac1
dashboard link: https://syzkaller.appspot.com/bug?extid=76a43f2b4d34cfc53548
compiler: clang version 9.0.0 (/home/glider/llvm/clang
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10dde730e00000
The bug was bisected to:
commit 452c2779410a03ac0c6be0a8a91c83aa80bdd7e5
Author: Deepa Dinamani <deepa.kernel@gmail.com>
Date: Fri Mar 8 20:40:03 2019 +0000
fs: sysv: Initialize filesystem timestamp ranges
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13c6e2bb600000
final crash: https://syzkaller.appspot.com/x/report.txt?x=1026e2bb600000
console output: https://syzkaller.appspot.com/x/log.txt?x=17c6e2bb600000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+76a43f2b4d34cfc53548@syzkaller.appspotmail.com
Fixes: 452c2779410a ("fs: sysv: Initialize filesystem timestamp ranges")
==================================================================
BUG: KASAN: use-after-free in mnt_warn_timestamp_expiry+0x4a/0x250
fs/namespace.c:2471
Read of size 8 at addr ffff888099937328 by task syz-executor.1/18510
CPU: 0 PID: 18510 Comm: syz-executor.1 Not tainted 5.4.0-rc3+ #0
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+0x1d8/0x2f8 lib/dump_stack.c:113
print_address_description+0x75/0x5c0 mm/kasan/report.c:374
__kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
kasan_report+0x26/0x50 mm/kasan/common.c:634
__asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
mnt_warn_timestamp_expiry+0x4a/0x250 fs/namespace.c:2471
do_new_mount_fc fs/namespace.c:2773 [inline]
do_new_mount fs/namespace.c:2825 [inline]
do_mount+0x2160/0x2510 fs/namespace.c:3143
ksys_mount+0xcc/0x100 fs/namespace.c:3352
__do_sys_mount fs/namespace.c:3366 [inline]
__se_sys_mount fs/namespace.c:3363 [inline]
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3363
do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a59
Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1f46735c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459a59
RDX: 0000000020000a40 RSI: 00000000200005c0 RDI: 0000000000000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f467366d4
R13: 00000000004c62a4 R14: 00000000004db438 R15: 00000000ffffffff
Allocated by task 18510:
save_stack mm/kasan/common.c:69 [inline]
set_track mm/kasan/common.c:77 [inline]
__kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518
slab_post_alloc_hook mm/slab.h:584 [inline]
slab_alloc mm/slab.c:3319 [inline]
kmem_cache_alloc+0x1f5/0x2e0 mm/slab.c:3483
kmem_cache_zalloc include/linux/slab.h:680 [inline]
alloc_vfsmnt+0x27/0x470 fs/namespace.c:177
vfs_create_mount+0x87/0x440 fs/namespace.c:940
do_new_mount_fc fs/namespace.c:2763 [inline]
do_new_mount fs/namespace.c:2825 [inline]
do_mount+0x1ee0/0x2510 fs/namespace.c:3143
ksys_mount+0xcc/0x100 fs/namespace.c:3352
__do_sys_mount fs/namespace.c:3366 [inline]
__se_sys_mount fs/namespace.c:3363 [inline]
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3363
do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 16:
save_stack mm/kasan/common.c:69 [inline]
set_track mm/kasan/common.c:77 [inline]
kasan_set_free_info mm/kasan/common.c:332 [inline]
__kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
__cache_free mm/slab.c:3425 [inline]
kmem_cache_free+0x81/0xf0 mm/slab.c:3693
free_vfsmnt fs/namespace.c:554 [inline]
delayed_free_vfsmnt+0x74/0x80 fs/namespace.c:559
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch kernel/rcu/tree.c:2157 [inline]
rcu_core+0x843/0x1050 kernel/rcu/tree.c:2377
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386
__do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:766
The buggy address belongs to the object at ffff888099937300
which belongs to the cache mnt_cache of size 312
The buggy address is located 40 bytes inside of
312-byte region [ffff888099937300, ffff888099937438)
The buggy address belongs to the page:
page:ffffea0002664dc0 refcount:1 mapcount:0 mapping:ffff8880aa5a9a80
index:0xffff888099937180
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea000285d4c8 ffffea00026ab308 ffff8880aa5a9a80
raw: ffff888099937180 ffff888099937000 0000000100000008 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888099937200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888099937280: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
> ffff888099937300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888099937380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888099937400: fb fb fb fb fb fb fb fc 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#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
next reply other threads:[~2019-10-17 1:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-17 1:42 syzbot [this message]
2019-10-17 1:47 ` KASAN: use-after-free Read in mnt_warn_timestamp_expiry Eric Biggers
2019-10-17 1:58 ` Al Viro
2019-10-17 2:27 ` Eric Biggers
2019-10-17 2:37 ` Al Viro
2019-10-17 2:50 ` 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=0000000000007f489b0595115374@google.com \
--to=syzbot+76a43f2b4d34cfc53548@syzkaller.appspotmail.com \
--cc=akpm@osdl.org \
--cc=deepa.kernel@gmail.com \
--cc=hch@infradead.org \
--cc=jlayton@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lkundrak@v3.sk \
--cc=syzkaller-bugs@googlegroups.com \
--cc=tklauser@nuerscht.ch \
--cc=trond.myklebust@fys.uio.no \
--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.