From: syzbot <syzbot+a98eee31f5df4261d88c@syzkaller.appspotmail.com>
To: allison@lohutok.net, armijn@tjaldur.nl, ast@kernel.org,
bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net,
gregkh@linuxfoundation.org, jakub.kicinski@netronome.com,
jhs@mojatatu.com, jiri@resnulli.us, kafai@fb.com,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
songliubraving@fb.com, syzkaller-bugs@googlegroups.com,
tglx@linutronix.de, xiyou.wangcong@gmail.com, yhs@fb.com
Subject: WARNING: refcount bug in free_nsproxy (2)
Date: Tue, 14 Jan 2020 14:04:12 -0800 [thread overview]
Message-ID: <000000000000a539c1059c20c5aa@google.com> (raw)
Hello,
syzbot found the following crash on:
HEAD commit: 6c09d7db Add linux-next specific files for 20200110
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=102b2156e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=7dc7ab9739654fbe
dashboard link: https://syzkaller.appspot.com/bug?extid=a98eee31f5df4261d88c
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=162f16aee00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13457571e00000
The bug was bisected to:
commit 14215108a1fd7e002c0a1f9faf8fbaf41fdda50d
Author: Cong Wang <xiyou.wangcong@gmail.com>
Date: Thu Feb 21 05:37:42 2019 +0000
net_sched: initialize net pointer inside tcf_exts_init()
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1063da9ee00000
final crash: https://syzkaller.appspot.com/x/report.txt?x=1263da9ee00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1463da9ee00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a98eee31f5df4261d88c@syzkaller.appspotmail.com
Fixes: 14215108a1fd ("net_sched: initialize net pointer inside
tcf_exts_init()")
R13: 0000000000000008 R14: 0000000000000000 R15: 0000000000000000
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 9780 at lib/refcount.c:28
refcount_warn_saturate+0x1dc/0x1f0 lib/refcount.c:28
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 9780 Comm: syz-executor174 Not tainted
5.5.0-rc5-next-20200110-syzkaller #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+0x197/0x210 lib/dump_stack.c:118
panic+0x2e3/0x75c kernel/panic.c:221
__warn.cold+0x2f/0x3e kernel/panic.c:582
report_bug+0x289/0x300 lib/bug.c:195
fixup_bug arch/x86/kernel/traps.c:176 [inline]
fixup_bug arch/x86/kernel/traps.c:171 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:269
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:288
invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x1dc/0x1f0 lib/refcount.c:28
Code: e9 d8 fe ff ff 48 89 df e8 b1 a6 13 fe e9 85 fe ff ff e8 47 6e d5 fd
48 c7 c7 80 64 91 88 c6 05 4f 5b 00 07 01 e8 e3 f5 a5 fd <0f> 0b e9 ac fe
ff ff 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 48
RSP: 0018:ffffc90005fd7cf8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815e8546 RDI: fffff52000bfaf91
RBP: ffffc90005fd7d08 R08: ffff8880a65ee500 R09: ffffed1015d26659
R10: ffffed1015d26658 R11: ffff8880ae9332c7 R12: 0000000000000003
R13: ffff88809aff6040 R14: ffff88809aff6044 R15: 00000000000002bc
refcount_sub_and_test include/linux/refcount.h:261 [inline]
refcount_dec_and_test include/linux/refcount.h:281 [inline]
put_net include/net/net_namespace.h:259 [inline]
free_nsproxy+0x2eb/0x330 kernel/nsproxy.c:180
switch_task_namespaces+0xb3/0xd0 kernel/nsproxy.c:225
exit_task_namespaces+0x18/0x20 kernel/nsproxy.c:230
do_exit+0xbc6/0x2f70 kernel/exit.c:800
do_group_exit+0x135/0x360 kernel/exit.c:899
__do_sys_exit_group kernel/exit.c:910 [inline]
__se_sys_exit_group kernel/exit.c:908 [inline]
__x64_sys_exit_group+0x44/0x50 kernel/exit.c:908
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441228
Code: 74 20 63 6f 64 65 20 62 61 73 65 2e 00 00 00 00 00 00 72 73 79 73 6c
6f 67 64 3a 20 24 41 62 6f 72 74 4f 6e 55 6e 63 6c 65 61 <6e> 43 6f 6e 66
69 67 20 69 73 20 73 65 74 2c 20 61 6e 64 20 63 6f
RSP: 002b:00007ffedb54aa88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000441228
RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
RBP: 00000000004c79d0 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006daa80 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..
---
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
reply other threads:[~2020-01-14 22:04 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=000000000000a539c1059c20c5aa@google.com \
--to=syzbot+a98eee31f5df4261d88c@syzkaller.appspotmail.com \
--cc=allison@lohutok.net \
--cc=armijn@tjaldur.nl \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=jakub.kicinski@netronome.com \
--cc=jhs@mojatatu.com \
--cc=jiri@resnulli.us \
--cc=kafai@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=songliubraving@fb.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=tglx@linutronix.de \
--cc=xiyou.wangcong@gmail.com \
--cc=yhs@fb.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.