[PATCH] Check if skb_alloc returns Null in function fw_download_code

[PATCH] Check if skb_alloc returns Null in function fw_download_code

[Nicholas Krause]

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
---
 drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
index 1a95d1f..11e915e 100644
--- a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
+++ b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
@@ -61,11 +61,13 @@ static bool fw_download_code(struct net_device *dev, u8 *code_virtual_address,
 		}
 
 		skb  = dev_alloc_skb(frag_length + 4);
+		if (!skb) {
 		memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev));
 		tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
 		tcb_desc->queue_index = TXCMD_QUEUE;
 		tcb_desc->bCmdOrInit = DESC_PACKET_TYPE_INIT;
 		tcb_desc->bLastIniPkt = bLastIniPkt;
+		}
 
 		seg_ptr = skb->data;
 		for (i = 0; i < frag_length; i += 4) {
-- 
1.9.1

Re: [PATCH] Check if skb_alloc returns Null in function fw_download_code

[Greg KH]

On Mon, Jun 16, 2014 at 11:23:13PM -0400, Nicholas Krause wrote:
> Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
> ---
>  drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
> index 1a95d1f..11e915e 100644
> --- a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
> +++ b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
> @@ -61,11 +61,13 @@ static bool fw_download_code(struct net_device *dev, u8 *code_virtual_address,
>  		}
>  
>  		skb  = dev_alloc_skb(frag_length + 4);
> +		if (!skb) {
>  		memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev));
>  		tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
>  		tcb_desc->queue_index = TXCMD_QUEUE;
>  		tcb_desc->bCmdOrInit = DESC_PACKET_TYPE_INIT;
>  		tcb_desc->bLastIniPkt = bLastIniPkt;
> +		}
>  

Please run your patches through scripts/checkpatch.pl to find the errors
before sending them out and having someone else point them out to you...

thanks,

greg k-h

Re: [PATCH] Check if skb_alloc returns Null in function fw_download_code

[Dave Jones]

On Mon, Jun 16, 2014 at 09:07:45PM -0700, Greg KH wrote:
 > On Mon, Jun 16, 2014 at 11:23:13PM -0400, Nicholas Krause wrote:
 > > Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
 > > ---
 > >  drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c | 2 ++
 > >  1 file changed, 2 insertions(+)
 > > 
 > > diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
 > > index 1a95d1f..11e915e 100644
 > > --- a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
 > > +++ b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
 > > @@ -61,11 +61,13 @@ static bool fw_download_code(struct net_device *dev, u8 *code_virtual_address,
 > >  		}
 > >  
 > >  		skb  = dev_alloc_skb(frag_length + 4);
 > > +		if (!skb) {
 > >  		memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev));
 > >  		tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
 > >  		tcb_desc->queue_index = TXCMD_QUEUE;
 > >  		tcb_desc->bCmdOrInit = DESC_PACKET_TYPE_INIT;
 > >  		tcb_desc->bLastIniPkt = bLastIniPkt;
 > > +		}
 > >  
 > 
 > Please run your patches through scripts/checkpatch.pl to find the errors
 > before sending them out and having someone else point them out to you...

I suspect checkpatch would pick up the indentation mess, but
indentation is the least of this patch's problems.

if that alloc_skb fails, going around the loop again is pointless, and
harmful. (we'll oops right below that added bracket).

on failure, this should be returning 0 so that the caller
handles the failure appropriately.

	Dave

Re: [PATCH] Check if skb_alloc returns Null in function fw_download_code

[Dan Carpenter]

On Mon, Jun 16, 2014 at 11:23:13PM -0400, Nicholas Krause wrote:
> Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
> ---
>  drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
> index 1a95d1f..11e915e 100644
> --- a/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
> +++ b/drivers/staging/rtl8192e/rtl8192e/r8192E_firmware.c
> @@ -61,11 +61,13 @@ static bool fw_download_code(struct net_device *dev, u8 *code_virtual_address,
>  		}
>  
>  		skb  = dev_alloc_skb(frag_length + 4);
> +		if (!skb) {

This test is reversed and causes a NULL dereference on the next line.

regards,
dan carpenter

>  		memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev));
>  		tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
>  		tcb_desc->queue_index = TXCMD_QUEUE;
>  		tcb_desc->bCmdOrInit = DESC_PACKET_TYPE_INIT;
>  		tcb_desc->bLastIniPkt = bLastIniPkt;
> +		}
>  
>  		seg_ptr = skb->data;
>  		for (i = 0; i < frag_length; i += 4) {
> -- 
> 1.9.1
> 
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