[PATCH net] net: Zero ifla_vf_info in rtnl_fill_vfinfo()

[PATCH net] net: Zero ifla_vf_info in rtnl_fill_vfinfo()

[Yuval Mintz]

Some of the structure's fields are not initialized by the
rtnetlink. If driver doesn't set those in ndo_get_vf_config(),
they'd leak memory to user.

Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
CC: Michal Schmidt <mschmidt@redhat.com>
---
 net/core/rtnetlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 9e2c0a7..5e61456 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1124,6 +1124,8 @@ static noinline_for_stack int rtnl_fill_vfinfo(struct sk_buff *skb,
 	struct ifla_vf_mac vf_mac;
 	struct ifla_vf_info ivi;
 
+	memset(&ivi, 0, sizeof(ivi));
+
 	/* Not all SR-IOV capable drivers support the
 	 * spoofcheck and "RSS query enable" query.  Preset to
 	 * -1 so the user space tool can detect that the driver
@@ -1132,7 +1134,6 @@ static noinline_for_stack int rtnl_fill_vfinfo(struct sk_buff *skb,
 	ivi.spoofchk = -1;
 	ivi.rss_query_en = -1;
 	ivi.trusted = -1;
-	memset(ivi.mac, 0, sizeof(ivi.mac));
 	/* The default value for VF link state is "auto"
 	 * IFLA_VF_LINK_STATE_AUTO which equals zero
 	 */
-- 
2.9.4

Re: [PATCH net] net: Zero ifla_vf_info in rtnl_fill_vfinfo()

[Greg Rose]

On 06/07/2017 11:00 AM, Yuval Mintz wrote:
> Some of the structure's fields are not initialized by the
> rtnetlink. If driver doesn't set those in ndo_get_vf_config(),
> they'd leak memory to user.
>
> Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
> CC: Michal Schmidt <mschmidt@redhat.com>
> ---
>   net/core/rtnetlink.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 9e2c0a7..5e61456 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -1124,6 +1124,8 @@ static noinline_for_stack int rtnl_fill_vfinfo(struct sk_buff *skb,
>       struct ifla_vf_mac vf_mac;
>       struct ifla_vf_info ivi;
>
> +    memset(&ivi, 0, sizeof(ivi));
> +
>       /* Not all SR-IOV capable drivers support the
>        * spoofcheck and "RSS query enable" query.  Preset to
>        * -1 so the user space tool can detect that the driver
> @@ -1132,7 +1134,6 @@ static noinline_for_stack int rtnl_fill_vfinfo(struct sk_buff *skb,
>       ivi.spoofchk = -1;
>       ivi.rss_query_en = -1;
>       ivi.trusted = -1;
> -    memset(ivi.mac, 0, sizeof(ivi.mac));
>       /* The default value for VF link state is "auto"
>        * IFLA_VF_LINK_STATE_AUTO which equals zero
>        */
>
It's been a few years since I worked in this code but I do recall this portion.  Good idea...

Thanks!

Reviewed-by: Greg Rose <gvrose8192@gmail.com>

Re: [PATCH net] net: Zero ifla_vf_info in rtnl_fill_vfinfo()

[David Miller]

From: Yuval Mintz <Yuval.Mintz@cavium.com>
Date: Wed, 7 Jun 2017 21:00:33 +0300

> Some of the structure's fields are not initialized by the
> rtnetlink. If driver doesn't set those in ndo_get_vf_config(),
> they'd leak memory to user.
> 
> Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
> CC: Michal Schmidt <mschmidt@redhat.com>

Good catch, applied and queued up for -stable, thanks.