RE: [PATCH] video_device: don't free_irq() an element past arrayvpif_obj.dev[] and fix test

From: Karicheri, Muralidharan
Date: Thu Feb 18 2010 - 11:32:44 EST


Roel,

Thanks for the patch.

>In vpif_get_std_info(): std_info doesn't need the NULL test, it was already
>dereferenced anyway. If std_info->stdid is 0 we could early return -1.
>
>In vpif_probe(): local variable q was only assigned. If we error out with
>either last two goto's then j equals VPIF_DISPLAY_MAX_DEVICES. So after the
>probe_out: label, k also reaches VPIF_DISPLAY_MAX_DEVICES after the loop.
>In
>the first iteration in the loop after vpif_int_err: a free_irq() can occur
>of an element &vpif_obj.dev[VPIF_DISPLAY_MAX_DEVICES]->channel_id which is
>outside vpif_obj.dev[] array boundaries.
>
>Signed-off-by: Roel Kluin <roel.kluin@xxxxxxxxx>
>---
>Or am I mistaken?
>
>diff --git a/drivers/media/video/davinci/vpif_display.c
>b/drivers/media/video/davinci/vpif_display.c
>index dfddef7..8f6605d 100644
>--- a/drivers/media/video/davinci/vpif_display.c
>+++ b/drivers/media/video/davinci/vpif_display.c
>@@ -383,7 +383,7 @@ static int vpif_get_std_info(struct channel_obj *ch)
> int index;
>
> std_info->stdid = vid_ch->stdid;
>- if (!std_info)
>+ if (!std_info->stdid)
> return -1;
>
This is a NACK. We shouldn't check for stdid since the function is supposed
to update std_info. So just remove

if (!std_info)
return -1;

I am okay with the below change. So please re-submit the patch with the
above change and my ACK.

Thanks

Murali

> for (index = 0; index < ARRAY_SIZE(ch_params); index++) {
>@@ -1423,7 +1423,7 @@ static __init int vpif_probe(struct platform_device
>*pdev)
> {
> struct vpif_subdev_info *subdevdata;
> struct vpif_display_config *config;
>- int i, j = 0, k, q, m, err = 0;
>+ int i, j = 0, k, m, err = 0;
> struct i2c_adapter *i2c_adap;
> struct common_obj *common;
> struct channel_obj *ch;
>@@ -1573,10 +1573,12 @@ probe_out:
> video_device_release(ch->video_dev);
> ch->video_dev = NULL;
> }
>+ if (k == VPIF_DISPLAY_MAX_DEVICES)
>+ k = VPIF_DISPLAY_MAX_DEVICES - 1;
> vpif_int_err:
> v4l2_device_unregister(&vpif_obj.v4l2_dev);
> vpif_err("VPIF IRQ request failed\n");
>- for (q = k; k >= 0; k--) {
>+ for (; k >= 0; k--) {
> for (m = i; m >= res->start; m--)
> free_irq(m, (void *)(&vpif_obj.dev[k]->channel_id));
> res = platform_get_resource(pdev, IORESOURCE_IRQ, k-1);
>--
>To unsubscribe from this list: send the line "unsubscribe linux-media" in
>the body of a message to majordomo@xxxxxxxxxxxxxxx
>More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/