Re: [PATCH 1/3] cw1200: Don't leak memory if krealloc failes

From: Johannes Thumshirn
Date: Fri Sep 30 2016 - 09:00:44 EST


On Fri, Sep 30, 2016 at 03:56:45PM +0300, Sergei Shtylyov wrote:
> Hello.
>
> On 9/30/2016 3:11 PM, Johannes Thumshirn wrote:
>
> > The call to krealloc() in wsm_buf_reserve() directly assigns the newly
> > returned memory to buf->begin. This is all fine except when krealloc()
> > failes we loose the ability to free the old memory pointed to by
>
> Fails.
>
> > buf->begin. If we just create a temporary variable to assign memory to
> > and assign the memory to it we can mitigate the memory leak.
> >
> > Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
> > ---
> > drivers/net/wireless/st/cw1200/wsm.c | 16 +++++++++-------
> > 1 file changed, 9 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/net/wireless/st/cw1200/wsm.c b/drivers/net/wireless/st/cw1200/wsm.c
> > index 680d60e..12fad99 100644
> > --- a/drivers/net/wireless/st/cw1200/wsm.c
> > +++ b/drivers/net/wireless/st/cw1200/wsm.c
> > @@ -1807,16 +1807,18 @@ static int wsm_buf_reserve(struct wsm_buf *buf, size_t extra_size)
> > {
> > size_t pos = buf->data - buf->begin;
> > size_t size = pos + extra_size;
> > + u8 *tmp;
> >
> > size = round_up(size, FWLOAD_BLOCK_SIZE);
> >
> > - buf->begin = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA);
> > - if (buf->begin) {
> > - buf->data = &buf->begin[pos];
> > - buf->end = &buf->begin[size];
> > - return 0;
> > - } else {
> > - buf->end = buf->data = buf->begin;
> > + tmp = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA);
> > + if (tmp) {
>
> !tmp, you mean?

Yes, I've already sent out a v2.

--
Johannes Thumshirn Storage
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