Re: [PATCH] net: ethernet: marvell: sky2.c: Cleaning up missing null-terminate in conjunction with strncpy

From: Stephen Hemminger
Date: Sun Sep 14 2014 - 22:06:28 EST


On Sun, 14 Sep 2014 19:33:43 +0200
Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx> wrote:

> Replacing strncpy with strlcpy to avoid strings that lacks null terminate.
>
> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/marvell/sky2.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c
> index dba48a5c..7053d38 100644
> --- a/drivers/net/ethernet/marvell/sky2.c
> +++ b/drivers/net/ethernet/marvell/sky2.c
> @@ -4907,7 +4907,7 @@ static const char *sky2_name(u8 chipid, char *buf, int sz)
> };
>
> if (chipid >= CHIP_ID_YUKON_XL && chipid <= CHIP_ID_YUKON_OP_2)
> - strncpy(buf, name[chipid - CHIP_ID_YUKON_XL], sz);
> + strlcpy(buf, name[chipid - CHIP_ID_YUKON_XL], sz);
> else
> snprintf(buf, sz, "(chip %#x)", chipid);
> return buf;

Useless and unnecessary since the list of names is right there.
Why not avoid the copy all together?

Subject: sky2: avoid strncpy

Don't use strncpy() since security thought police think it is bad.

Signed-off-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>


--- a/drivers/net/ethernet/marvell/sky2.c 2014-08-25 09:01:16.292060455 -0700
+++ b/drivers/net/ethernet/marvell/sky2.c 2014-09-14 19:02:26.731034094 -0700
@@ -4889,7 +4889,7 @@ static int sky2_test_msi(struct sky2_hw
}

/* This driver supports yukon2 chipset only */
-static const char *sky2_name(u8 chipid, char *buf, int sz)
+static const char *sky2_name(u8 chipid)
{
const char *name[] = {
"XL", /* 0xb3 */
@@ -4905,11 +4905,12 @@ static const char *sky2_name(u8 chipid,
"OptimaEEE", /* 0xbd */
"Optima 2", /* 0xbe */
};
+ static char buf[16];

if (chipid >= CHIP_ID_YUKON_XL && chipid <= CHIP_ID_YUKON_OP_2)
- strncpy(buf, name[chipid - CHIP_ID_YUKON_XL], sz);
- else
- snprintf(buf, sz, "(chip %#x)", chipid);
+ return name[chipid - CHIP_ID_YUKON_XL];
+
+ snprintf(buf, sizeof(buf), "(chip %#x)", chipid);
return buf;
}

@@ -4919,7 +4920,6 @@ static int sky2_probe(struct pci_dev *pd
struct sky2_hw *hw;
int err, using_dac = 0, wol_default;
u32 reg;
- char buf1[16];

err = pci_enable_device(pdev);
if (err) {
@@ -5014,7 +5014,7 @@ static int sky2_probe(struct pci_dev *pd
}

dev_info(&pdev->dev, "Yukon-2 %s chip revision %d\n",
- sky2_name(hw->chip_id, buf1, sizeof(buf1)), hw->chip_rev);
+ sky2_name(hw->chip_id), hw->chip_rev);

sky2_reset(hw);

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