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

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* [PATCH 1/3] cw1200: Don't leak memory if krealloc failes
@ 2016-09-30 12:11 Johannes Thumshirn
       [not found] ` <1475237495-15030-1-git-send-email-jthumshirn-l3A5Bk7waGM@public.gmane.org>
  2016-09-30 12:56 ` Sergei Shtylyov
  0 siblings, 2 replies; 5+ messages in thread
From: Johannes Thumshirn @ 2016-09-30 12:11 UTC (permalink / raw)
  To: Solomon Peachy, Kalle Valo
  Cc: linux-wireless, netdev, linux-kernel, Johannes Thumshirn

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
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@suse.de>
---
 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) {
+		wsm_buf_deinit(buf);
 		return -ENOMEM;
 	}
+
+	buf->begin = tmp;
+	buf->data = &buf->begin[pos];
+	buf->end = &buf->begin[size];
+	return 0;
 }
-- 
1.8.5.6

^ permalink raw reply related	[flat|nested] 5+ messages in thread

[parent not found: <1475237495-15030-1-git-send-email-jthumshirn-l3A5Bk7waGM@public.gmane.org>]

* Re: [PATCH 1/3] cw1200: Don't leak memory if krealloc failes
       [not found] ` <1475237495-15030-1-git-send-email-jthumshirn-l3A5Bk7waGM@public.gmane.org>
@ 2016-09-30 12:29   ` Johannes Berg
  2016-09-30 12:33     ` Johannes Thumshirn
  0 siblings, 1 reply; 5+ messages in thread
From: Johannes Berg @ 2016-09-30 12:29 UTC (permalink / raw)
  To: Johannes Thumshirn, Solomon Peachy, Kalle Valo
  Cc: linux-wireless-u79uwXL29TY76Z2rM5mHXA,
	netdev-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA


> +	tmp = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA);
> +	if (tmp) {
> 
I think that check is inverted?

johannes

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/3] cw1200: Don't leak memory if krealloc failes
  2016-09-30 12:29   ` Johannes Berg
@ 2016-09-30 12:33     ` Johannes Thumshirn
  0 siblings, 0 replies; 5+ messages in thread
From: Johannes Thumshirn @ 2016-09-30 12:33 UTC (permalink / raw)
  To: Johannes Berg
  Cc: Solomon Peachy, Kalle Valo, linux-wireless, netdev, linux-kernel

On Fri, Sep 30, 2016 at 02:29:39PM +0200, Johannes Berg wrote:
> 
> > +	tmp = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA);
> > +	if (tmp) {
> > 
> I think that check is inverted?
> 
> johannes

Fu.. you're right, of cause it's !tmp.

I'll resend.

Thanks,
	Johannes

-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/3] cw1200: Don't leak memory if krealloc failes
  2016-09-30 12:11 [PATCH 1/3] cw1200: Don't leak memory if krealloc failes Johannes Thumshirn
       [not found] ` <1475237495-15030-1-git-send-email-jthumshirn-l3A5Bk7waGM@public.gmane.org>
@ 2016-09-30 12:56 ` Sergei Shtylyov
       [not found]   ` <25a38254-f0e3-1f4e-de46-688d9fd1b736-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
  1 sibling, 1 reply; 5+ messages in thread
From: Sergei Shtylyov @ 2016-09-30 12:56 UTC (permalink / raw)
  To: Johannes Thumshirn, Solomon Peachy, Kalle Valo
  Cc: linux-wireless, netdev, linux-kernel

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@suse.de>
> ---
>  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?

> +		wsm_buf_deinit(buf);
>  		return -ENOMEM;
>  	}
> +
> +	buf->begin = tmp;
> +	buf->data = &buf->begin[pos];
> +	buf->end = &buf->begin[size];
> +	return 0;
>  }

MBR, Sergei

^ permalink raw reply	[flat|nested] 5+ messages in thread

[parent not found: <25a38254-f0e3-1f4e-de46-688d9fd1b736-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>]

* Re: [PATCH 1/3] cw1200: Don't leak memory if krealloc failes
       [not found]   ` <25a38254-f0e3-1f4e-de46-688d9fd1b736-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
@ 2016-09-30 13:00     ` Johannes Thumshirn
  0 siblings, 0 replies; 5+ messages in thread
From: Johannes Thumshirn @ 2016-09-30 13:00 UTC (permalink / raw)
  To: Sergei Shtylyov
  Cc: Solomon Peachy, Kalle Valo, linux-wireless-u79uwXL29TY76Z2rM5mHXA,
	netdev-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA

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-l3A5Bk7waGM@public.gmane.org>
> > ---
> >  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
jthumshirn-l3A5Bk7waGM@public.gmane.org                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

^ permalink raw reply	[flat|nested] 5+ messages in thread

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2016-09-30 12:11 [PATCH 1/3] cw1200: Don't leak memory if krealloc failes Johannes Thumshirn
     [not found] ` <1475237495-15030-1-git-send-email-jthumshirn-l3A5Bk7waGM@public.gmane.org>
2016-09-30 12:29   ` Johannes Berg
2016-09-30 12:33     ` Johannes Thumshirn
2016-09-30 12:56 ` Sergei Shtylyov
     [not found]   ` <25a38254-f0e3-1f4e-de46-688d9fd1b736-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-09-30 13:00     ` Johannes Thumshirn

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