2018-05-29 07:00:29

by Nick Desaulniers

Subject: [PATCH] video/hdmi: prefer strlcpy to strncpy

Fixes a stringop-truncation warning from gcc-8.

Signed-off-by: Nick Desaulniers <[email protected]>
---
drivers/video/hdmi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index 111a0ab..46c184c 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -168,8 +168,8 @@ int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
frame->version = 1;
frame->length = HDMI_SPD_INFOFRAME_SIZE;

- strncpy(frame->vendor, vendor, sizeof(frame->vendor));
- strncpy(frame->product, product, sizeof(frame->product));
+ strlcpy(frame->vendor, vendor, sizeof(frame->vendor));
+ strlcpy(frame->product, product, sizeof(frame->product));

return 0;
}
--
2.7.4

2018-05-30 02:00:29

by Nick Desaulniers

Subject: Re: [PATCH] video/hdmi: prefer strlcpy to strncpy

On Mon, May 28, 2018 at 11:59 PM, Nick Desaulniers
<[email protected]> wrote:
> Fixes a stringop-truncation warning from gcc-8.
>
> Signed-off-by: Nick Desaulniers <[email protected]>
> ---
> drivers/video/hdmi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> index 111a0ab..46c184c 100644
> --- a/drivers/video/hdmi.c
> +++ b/drivers/video/hdmi.c
> @@ -168,8 +168,8 @@ int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
> frame->version = 1;
> frame->length = HDMI_SPD_INFOFRAME_SIZE;
>
> - strncpy(frame->vendor, vendor, sizeof(frame->vendor));
> - strncpy(frame->product, product, sizeof(frame->product));
> + strlcpy(frame->vendor, vendor, sizeof(frame->vendor));
> + strlcpy(frame->product, product, sizeof(frame->product));
>
> return 0;
> }
> --
> 2.7.4
>

Eric points out this can leak kernel memory if size is less than length of src.