2017-12-30 19:42:06

by Santosh Shilimkar

[permalink] [raw]
Subject: Re: KASAN: use-after-free Read in rds_find_bound

On 12/30/17 1:17 AM, syzbot wrote:
> Hello,
>
> syzkaller hit the following crash on
> fba961ab29e5ffb055592442808bb0f7962e05da
> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> Unfortunately, I don't have any reproducer for this bug yet.
>
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: [email protected]

Posted a fix[1] for above issue. Didn't test it but looks straight
forward.

Regards,
Santosh



2018-02-13 20:13:44

by Dmitry Vyukov

[permalink] [raw]
Subject: Re: KASAN: use-after-free Read in rds_find_bound

On Sat, Dec 30, 2017 at 8:41 PM, [email protected]
<[email protected]> wrote:
> On 12/30/17 1:17 AM, syzbot wrote:
>>
>> Hello,
>>
>> syzkaller hit the following crash on
>> fba961ab29e5ffb055592442808bb0f7962e05da
>> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
>> compiler: gcc (GCC) 7.1.1 20170620
>> .config is attached
>> Raw console output is attached.
>> Unfortunately, I don't have any reproducer for this bug yet.
>>
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: [email protected]
>
>
> Posted a fix[1] for above issue. Didn't test it but looks straight
> forward.


Hi Santosh,

What is that fix? You forgot to provide any link/reference. I also
don't see any patches from you at around that date...

2018-02-14 16:55:11

by Santosh Shilimkar

[permalink] [raw]
Subject: Re: KASAN: use-after-free Read in rds_find_bound

On 2/13/2018 12:12 PM, Dmitry Vyukov wrote:
> On Sat, Dec 30, 2017 at 8:41 PM, [email protected]
> <[email protected]> wrote:
>> On 12/30/17 1:17 AM, syzbot wrote:
>>>
>>> Hello,
>>>
>>> syzkaller hit the following crash on
>>> fba961ab29e5ffb055592442808bb0f7962e05da
>>> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
>>> compiler: gcc (GCC) 7.1.1 20170620
>>> .config is attached
>>> Raw console output is attached.
>>> Unfortunately, I don't have any reproducer for this bug yet.
>>>
>>>
>>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>>> Reported-by: [email protected]
>>
>>
>> Posted a fix[1] for above issue. Didn't test it but looks straight
>> forward.
>
>
> Hi Santosh,
>
> What is that fix? You forgot to provide any link/reference. I also
> don't see any patches from you at around that date...
>
Fix [1] was later not added since there was a still a race. Wanted to
see if the issue re-appears after recent netns fix [2].

Regards,
Santosh


[1] https://patchwork.kernel.org/patch/10137901/
[2] https://patchwork.ozlabs.org/patch/868902/

2018-02-14 17:37:08

by Santosh Shilimkar

[permalink] [raw]
Subject: Re: KASAN: use-after-free Read in rds_find_bound

On 2/14/2018 9:14 AM, Dmitry Vyukov wrote:
> On Wed, Feb 14, 2018 at 5:53 PM, Santosh Shilimkar
> <[email protected]> wrote:

[...]

>>> Hi Santosh,
>>>
>>> What is that fix? You forgot to provide any link/reference. I also
>>> don't see any patches from you at around that date...
>>>
>> Fix [1] was later not added since there was a still a race. Wanted to
>> see if the issue re-appears after recent netns fix [2].
>
>
> We will not see if the bug re-appears or not until this bug is closed.
> Please see this recent discussion about another rds bug:
> https://groups.google.com/d/msg/syzkaller-bugs/3XjmOzr5jRU/g7pXIsY1BgAJ
> In the current state syzbot will never report bugs in these functions again.
>
OK. Can you close that one then in that case ?

2018-02-14 18:01:30

by Santosh Shilimkar

[permalink] [raw]
Subject: Re: KASAN: use-after-free Read in rds_find_bound

On 2/14/2018 9:52 AM, Dmitry Vyukov wrote:
> On Wed, Feb 14, 2018 at 6:35 PM, Santosh Shilimkar
> <[email protected]> wrote:
>>>>> Hi Santosh,
>>>>>
>>>>> What is that fix? You forgot to provide any link/reference. I also
>>>>> don't see any patches from you at around that date...
>>>>>
>>>> Fix [1] was later not added since there was a still a race. Wanted to
>>>> see if the issue re-appears after recent netns fix [2].
>>>
>>>
>>>
>>> We will not see if the bug re-appears or not until this bug is closed.
>>> Please see this recent discussion about another rds bug:
>>> https://groups.google.com/d/msg/syzkaller-bugs/3XjmOzr5jRU/g7pXIsY1BgAJ
>>> In the current state syzbot will never report bugs in these functions
>>> again.
>>>
>> OK. Can you close that one then in that case ?
>
> Anybody can do this:
>
I see.

> #syz fix: rds: tcp: use rds_destroy_pending() to synchronize
> netns/module teardown and rds connection/workq management
>
> syzbot provides full self-service, see first email and in particular this:
> https://github.com/google/syzkaller/blob/master/docs/syzbot.md#communication-with-syzbot
>
ok will have a look.

Regards,
Santosh

2018-02-14 20:09:54

by Dmitry Vyukov

[permalink] [raw]
Subject: Re: KASAN: use-after-free Read in rds_find_bound

On Wed, Feb 14, 2018 at 5:53 PM, Santosh Shilimkar
<[email protected]> wrote:
>>> On 12/30/17 1:17 AM, syzbot wrote:
>>>>
>>>>
>>>> Hello,
>>>>
>>>> syzkaller hit the following crash on
>>>> fba961ab29e5ffb055592442808bb0f7962e05da
>>>> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
>>>> compiler: gcc (GCC) 7.1.1 20170620
>>>> .config is attached
>>>> Raw console output is attached.
>>>> Unfortunately, I don't have any reproducer for this bug yet.
>>>>
>>>>
>>>> IMPORTANT: if you fix the bug, please add the following tag to the
>>>> commit:
>>>> Reported-by: [email protected]
>>>
>>>
>>>
>>> Posted a fix[1] for above issue. Didn't test it but looks straight
>>> forward.
>>
>>
>>
>> Hi Santosh,
>>
>> What is that fix? You forgot to provide any link/reference. I also
>> don't see any patches from you at around that date...
>>
> Fix [1] was later not added since there was a still a race. Wanted to
> see if the issue re-appears after recent netns fix [2].


We will not see if the bug re-appears or not until this bug is closed.
Please see this recent discussion about another rds bug:
https://groups.google.com/d/msg/syzkaller-bugs/3XjmOzr5jRU/g7pXIsY1BgAJ
In the current state syzbot will never report bugs in these functions again.

2018-02-14 20:11:11

by Dmitry Vyukov

[permalink] [raw]
Subject: Re: KASAN: use-after-free Read in rds_find_bound

On Wed, Feb 14, 2018 at 6:35 PM, Santosh Shilimkar
<[email protected]> wrote:
>>>> Hi Santosh,
>>>>
>>>> What is that fix? You forgot to provide any link/reference. I also
>>>> don't see any patches from you at around that date...
>>>>
>>> Fix [1] was later not added since there was a still a race. Wanted to
>>> see if the issue re-appears after recent netns fix [2].
>>
>>
>>
>> We will not see if the bug re-appears or not until this bug is closed.
>> Please see this recent discussion about another rds bug:
>> https://groups.google.com/d/msg/syzkaller-bugs/3XjmOzr5jRU/g7pXIsY1BgAJ
>> In the current state syzbot will never report bugs in these functions
>> again.
>>
> OK. Can you close that one then in that case ?

Anybody can do this:

#syz fix: rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management

syzbot provides full self-service, see first email and in particular this:
https://github.com/google/syzkaller/blob/master/docs/syzbot.md#communication-with-syzbot

Thanks