Re: [PATCH] [RESEND] devres: Fix possible use after free

[Maxin B John <maxin.john@gmail.com>]

Hi,

On Tue, Jun 14, 2011 at 8:15 AM, Tejun Heo <tj@kernel.org> wrote:
> On Tue, Jun 14, 2011 at 10:07:32AM +0300, Maxin B John wrote:
>> A freed pointer is passed as an argument to the function "devres_destroy()" in
>> "kernel/irq/devres.c" and "lib/devres.c". This patch fixes the possible use
>> after free.
>>
>> It's notabug at this time, but the code is dangerous.
>
> The code is not dangerous.  The pointer value is used strictly as key
> and the code path is always properly serialized.  The change is to
> appease access-after-free detection logic, similar to the way we
> change the code to better accomodate sparse or other code analysys
> tools.  Can you please update the patch description to reflect that?

You are right. I shouldn't have mentioned it as dangerous. I was trying to
make this patch description similar to the description present in the
previous patch:
http://www.spinics.net/lists/mm-commits/msg84313.html

This patch silences the Coverity Prevent's complains about this as
use-after-free bug. Please let me know if the updated patch description is OK.

"
A freed pointer is passed as an argument to the function "devres_destroy()" in
"kernel/irq/devres.c" and "lib/devres.c". This patch fixes the possible use
after free.
The change silences the static analysis tool (Coverity Prevent) complains
about this as use-after-free bug.
"

Best Regards,
Maxin