2014-06-17 03:23:19

by Nicholas Krause

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

Signed-off-by: Nicholas Krause <[email protected]>
---
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

2014-06-17 04:07:55

by Greg Kroah-Hartman

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

On Mon, Jun 16, 2014 at 11:23:13PM -0400, Nicholas Krause wrote:
> Signed-off-by: Nicholas Krause <[email protected]>
> ---
> 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

2014-06-17 04:20:33

by Dave Jones

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

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 <[email protected]>
> > ---
> > 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

2014-06-17 06:08:02

by Dan Carpenter

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

On Mon, Jun 16, 2014 at 11:23:13PM -0400, Nicholas Krause wrote:
> Signed-off-by: Nicholas Krause <[email protected]>
> ---
> 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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