[v1] bnxt: avoid overflow in bnxt_get_nvram_directory()

[PATCH] bnxt: avoid overflow in bnxt_get_nvram_directory()

Posted by Maxim Korotkov 2 years, 6 months ago

The value of an arithmetic expression is subject
of possible overflow due to a failure to cast operands to a larger data
type before performing arithmetic. Used macro for multiplication instead
operator for avoiding overflow.

Found by Security Code and Linux Verification
Center (linuxtesting.org) with SVACE.

Signed-off-by: Maxim Korotkov <korotkov.maxim.s@gmail.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index ec573127b707..696f32dfe41f 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -2862,7 +2862,7 @@ static int bnxt_get_nvram_directory(struct net_device *dev, u32 len, u8 *data)
 	if (rc)
 		return rc;
 
-	buflen = dir_entries * entry_length;
+	buflen = mul_u32_u32(dir_entries, entry_length);
 	buf = hwrm_req_dma_slice(bp, req, buflen, &dma_handle);
 	if (!buf) {
 		hwrm_req_drop(bp, req);
-- 
2.37.2

Re: [PATCH] bnxt: avoid overflow in bnxt_get_nvram_directory()

Posted by Pavan Chebbi 2 years, 6 months ago

On Sat, Feb 18, 2023 at 3:20 PM Maxim Korotkov
<korotkov.maxim.s@gmail.com> wrote:
>
> The value of an arithmetic expression is subject
> of possible overflow due to a failure to cast operands to a larger data
> type before performing arithmetic. Used macro for multiplication instead
> operator for avoiding overflow.
>
> Found by Security Code and Linux Verification
> Center (linuxtesting.org) with SVACE.
>

Looks OK to me. May need a fixes tag.

> Signed-off-by: Maxim Korotkov <korotkov.maxim.s@gmail.com>
> ---
>  drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> index ec573127b707..696f32dfe41f 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
> @@ -2862,7 +2862,7 @@ static int bnxt_get_nvram_directory(struct net_device *dev, u32 len, u8 *data)
>         if (rc)
>                 return rc;
>
> -       buflen = dir_entries * entry_length;
> +       buflen = mul_u32_u32(dir_entries, entry_length);
>         buf = hwrm_req_dma_slice(bp, req, buflen, &dma_handle);
>         if (!buf) {
>                 hwrm_req_drop(bp, req);
> --
> 2.37.2
>