Re: [PATCH][rfc] md: Close mem leak in userspace_ctr()

From: Jesper Juhl
Date: Fri Dec 17 2010 - 07:25:14 EST


On Tue, 14 Dec 2010, Mike Snitzer wrote:

> On Mon, Dec 13 2010 at 6:40pm -0500,
> Jesper Juhl <jj@xxxxxxxxxxxxx> wrote:
>
> > Hi,
> >
> > There's a small memory leak in
> > drivers/md/dm-log-userspace-base.c::userspace_ctr().
> >
> > The call to build_constructor_string() dynamically allocates memory for
> > its last argument, but we do not always clean up that allocated memory.
>
> I'm not seeing a leak.
>
> The kfree() that you've added to the build_constructor_string() failure
> path isn't needed because build_constructor_string() only returns error
> if the kzalloc() failed.
>

Hmm, that's true, assuming that there are no bugs (and never will be) in
strlen() or sprintf() that result in 'str_size' becoming negative the code
is safe. That's probably a safe assumption ;-)

Sorry about the noise.

--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
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