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From: Sasha Levin <sasha.levin@oracle.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tracepoint: don't make assumptions about length of string on task rename
Date: Tue, 01 Sep 2015 11:07:32 -0400	[thread overview]
Message-ID: <55E5BF34.8080005@oracle.com> (raw)
In-Reply-To: <20150828110251.41b6b805@gandalf.local.home>

On 08/28/2015 11:02 AM, Steven Rostedt wrote:
> On Fri, 28 Aug 2015 07:06:58 -0400
> Sasha Levin <sasha.levin@oracle.com> wrote:
> 
>> While the dest comm string size is assured to be at least TASK_COMM_LEN long,
>> doing a memcpy() also adds the assumption that the source is at least that
>> long as well, which isn't assured, and isn't true in cases such as:
>>
>> 	set_task_comm(worker->task, "kworker/dying");
>>
>> This leads to accessing invalid memory.
>>
>> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> 
> Acked-by: Steven Rostedt <rostedt@goodmis.org>
> 
> Should this go to stable as well?

Yup.

> Also, as the memcpy was just faster than a strcpy, the static length
> was used. Perhaps we should convert that to a dynamic length string.
> But that should be a separate patch as this one fixes a possible bug,
> and the conversion to a dynamic string is just an enhancement.

That'll slow things down for the common case, no?


Thanks,
Sasha


  reply	other threads:[~2015-09-01 15:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-28 11:06 [PATCH] tracepoint: don't make assumptions about length of string on task rename Sasha Levin
2015-08-28 15:02 ` Steven Rostedt
2015-09-01 15:07   ` Sasha Levin [this message]
2015-09-01 15:32     ` Steven Rostedt

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