Re: [PATCH] fbdev: fix possible NULL pointer derefernce

From: Jean-Christophe PLAGNIOL-VILLARD
Date: Wed Apr 16 2014 - 09:56:40 EST



On Apr 16, 2014, at 5:40 PM, Daeseok Youn <daeseok.youn@xxxxxxxxx> wrote:

>
> The spec->modedb can be NULL by fb_create_modedb().
>
> And also smatch says:
> drivers/video/fbdev/core/fbmon.c:975 fb_edid_to_monspecs() error:
> potential null dereference 'specs->modedb'.
> (fb_create_modedb returns null)
>
> Signed-off-by: Daeseok Youn <daeseok.youn@xxxxxxxxx>
> ---
> drivers/video/fbdev/core/fbmon.c | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/video/fbdev/core/fbmon.c b/drivers/video/fbdev/core/fbmon.c
> index c204ebe..db274ca 100644
> --- a/drivers/video/fbdev/core/fbmon.c
> +++ b/drivers/video/fbdev/core/fbmon.c
> @@ -966,6 +966,9 @@ void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
>
> specs->modedb = fb_create_modedb(edid, &specs->modedb_len);
>
> + if (!specs->modedb)
> + return;
> +

we need to return an error and trace it

Best Regards,
J.
> /*
> * Workaround for buggy EDIDs that sets that the first
> * detailed timing is preferred but has not detailed
> --
> 1.7.4.4
>

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