2006-10-18 04:32:09

by Amit Choudhary

Subject: [PATCH 2.6.19-rc2] [REVISED] drivers/media/video/se401.c: check kmalloc() return value.

Description: Check the return value of kmalloc() in function se401_start_stream(), in file drivers/media/video/se401.c.

Signed-off-by: Amit Choudhary <[email protected]>

diff --git a/drivers/media/video/se401.c b/drivers/media/video/se401.c
index 7aeec57..fe94227 100644
--- a/drivers/media/video/se401.c
+++ b/drivers/media/video/se401.c
@@ -450,6 +450,8 @@ static int se401_start_stream(struct usb
}
for (i=0; i<SE401_NUMSBUF; i++) {
se401->sbuf[i].data=kmalloc(SE401_PACKETSIZE, GFP_KERNEL);
+ if (!se401->sbuf[i].data)
+ goto nomem_err;
}

se401->bayeroffset=0;
@@ -458,13 +460,15 @@ static int se401_start_stream(struct usb
se401->scratch_overflow=0;
for (i=0; i<SE401_NUMSCRATCH; i++) {
se401->scratch[i].data=kmalloc(SE401_PACKETSIZE, GFP_KERNEL);
+ if (!se401->scratch[i].data)
+ goto nomem_err;
se401->scratch[i].state=BUFFER_UNUSED;
}

for (i=0; i<SE401_NUMSBUF; i++) {
urb=usb_alloc_urb(0, GFP_KERNEL);
if(!urb)
- return -ENOMEM;
+ goto nomem_err;

usb_fill_bulk_urb(urb, se401->dev,
usb_rcvbulkpipe(se401->dev, SE401_VIDEO_ENDPOINT),
@@ -482,6 +486,20 @@ static int se401_start_stream(struct usb
se401->framecount=0;

return 0;
+
+ nomem_err:
+ for (i=0; i<SE401_NUMSBUF; i++) {
+ usb_kill_urb(se401->urb[i]);
+ usb_free_urb(se401->urb[i]);
+ se401->urb[i] = NULL;
+ kfree(se401->sbuf[i].data);
+ se401->sbuf[i].data = NULL;
+ }
+ for (i=0; i<SE401_NUMSCRATCH; i++) {
+ kfree(se401->scratch[i].data);
+ se401->scratch[i].data = NULL;
+ }
+ return -ENOMEM;
}

static int se401_stop_stream(struct usb_se401 *se401)

2006-10-18 08:24:30

by Jarek Poplawski

Subject: Re: [PATCH 2.6.19-rc2] [REVISED] drivers/media/video/se401.c: check kmalloc() return value.

On 18-10-2006 06:31, Amit Choudhary wrote:
> Description: Check the return value of kmalloc() in function se401_start_stream(), in file drivers/media/video/se401.c.
>
> Signed-off-by: Amit Choudhary <[email protected]>
>
> diff --git a/drivers/media/video/se401.c b/drivers/media/video/se401.c
> index 7aeec57..fe94227 100644
> --- a/drivers/media/video/se401.c
> +++ b/drivers/media/video/se401.c
> @@ -450,6 +450,8 @@ static int se401_start_stream(struct usb
> }
> for (i=0; i<SE401_NUMSBUF; i++) {
> se401->sbuf[i].data=kmalloc(SE401_PACKETSIZE, GFP_KERNEL);
> + if (!se401->sbuf[i].data)
> + goto nomem_err;
> }
>
> se401->bayeroffset=0;
> @@ -458,13 +460,15 @@ static int se401_start_stream(struct usb
> se401->scratch_overflow=0;
> for (i=0; i<SE401_NUMSCRATCH; i++) {
> se401->scratch[i].data=kmalloc(SE401_PACKETSIZE, GFP_KERNEL);
> + if (!se401->scratch[i].data)
> + goto nomem_err;
> se401->scratch[i].state=BUFFER_UNUSED;
> }
>
> for (i=0; i<SE401_NUMSBUF; i++) {
> urb=usb_alloc_urb(0, GFP_KERNEL);
> if(!urb)
> - return -ENOMEM;
> + goto nomem_err;
>
> usb_fill_bulk_urb(urb, se401->dev,
> usb_rcvbulkpipe(se401->dev, SE401_VIDEO_ENDPOINT),
> @@ -482,6 +486,20 @@ static int se401_start_stream(struct usb
> se401->framecount=0;
>
> return 0;
> +
> + nomem_err:
> + for (i=0; i<SE401_NUMSBUF; i++) {
> + usb_kill_urb(se401->urb[i]);
> + usb_free_urb(se401->urb[i]);
> + se401->urb[i] = NULL;
> + kfree(se401->sbuf[i].data);
...

I see before se401_start_stream usually this is done:

static int se401_stop_stream(struct usb_se401 *se401)
{
...
for (i=0; i<SE401_NUMSBUF; i++) if (se401->urb[i]) {
usb_kill_urb(se401->urb[i]);
usb_free_urb(se401->urb[i]);
se401->urb[i]=NULL;
kfree(se401->sbuf[i].data);
}
for (i=0; i<SE401_NUMSCRATCH; i++) {
kfree(se401->scratch[i].data);
se401->scratch[i].data=NULL;
}

return 0;
}

... but because above there is no:
se401->sbuf[i].data=NULL;
after kfree(se401->sbuf[i].data);
it is possible that in se401_start_stream we have
kmalloc error for e.g. i == 0 but kfree for i >= 1,
which could be not NULL (but kfreed)...

Regards,

Jarek P.