* [PATCH net] rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string
@ 2017-05-04 14:48 Michal Schmidt
2017-05-04 15:24 ` David Miller
2017-05-04 16:14 ` David Ahern
0 siblings, 2 replies; 3+ messages in thread
From: Michal Schmidt @ 2017-05-04 14:48 UTC (permalink / raw)
To: netdev; +Cc: Thomas Haller, David Ahern
IFLA_PHYS_PORT_NAME is a string attribute, so terminate it with \0.
Otherwise libnl3 fails to validate netlink messages with this attribute.
"ip -detail a" assumes too that the attribute is NUL-terminated when
printing it. It often was, due to padding.
I noticed this as libvirtd failing to start on a system with sfc driver
after upgrading it to Linux 4.11, i.e. when sfc added support for
phys_port_name.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
---
net/core/rtnetlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index c4e84c5582..69daf393cb 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1056,7 +1056,7 @@ static int rtnl_phys_port_name_fill(struct sk_buff *skb, struct net_device *dev)
return err;
}
- if (nla_put(skb, IFLA_PHYS_PORT_NAME, strlen(name), name))
+ if (nla_put_string(skb, IFLA_PHYS_PORT_NAME, name))
return -EMSGSIZE;
return 0;
--
2.12.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net] rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string
2017-05-04 14:48 [PATCH net] rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string Michal Schmidt
@ 2017-05-04 15:24 ` David Miller
2017-05-04 16:14 ` David Ahern
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2017-05-04 15:24 UTC (permalink / raw)
To: mschmidt; +Cc: netdev, thaller, dsahern
From: Michal Schmidt <mschmidt@redhat.com>
Date: Thu, 4 May 2017 16:48:58 +0200
> IFLA_PHYS_PORT_NAME is a string attribute, so terminate it with \0.
> Otherwise libnl3 fails to validate netlink messages with this attribute.
> "ip -detail a" assumes too that the attribute is NUL-terminated when
> printing it. It often was, due to padding.
>
> I noticed this as libvirtd failing to start on a system with sfc driver
> after upgrading it to Linux 4.11, i.e. when sfc added support for
> phys_port_name.
>
> Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Good catch, applied and queued up for -stable, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net] rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string
2017-05-04 14:48 [PATCH net] rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string Michal Schmidt
2017-05-04 15:24 ` David Miller
@ 2017-05-04 16:14 ` David Ahern
1 sibling, 0 replies; 3+ messages in thread
From: David Ahern @ 2017-05-04 16:14 UTC (permalink / raw)
To: Michal Schmidt, netdev; +Cc: Thomas Haller
On 5/4/17 8:48 AM, Michal Schmidt wrote:
> IFLA_PHYS_PORT_NAME is a string attribute, so terminate it with \0.
> Otherwise libnl3 fails to validate netlink messages with this attribute.
> "ip -detail a" assumes too that the attribute is NUL-terminated when
> printing it. It often was, due to padding.
>
> I noticed this as libvirtd failing to start on a system with sfc driver
> after upgrading it to Linux 4.11, i.e. when sfc added support for
> phys_port_name.
>
> Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
> ---
> net/core/rtnetlink.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index c4e84c5582..69daf393cb 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -1056,7 +1056,7 @@ static int rtnl_phys_port_name_fill(struct sk_buff *skb, struct net_device *dev)
> return err;
> }
>
> - if (nla_put(skb, IFLA_PHYS_PORT_NAME, strlen(name), name))
> + if (nla_put_string(skb, IFLA_PHYS_PORT_NAME, name))
> return -EMSGSIZE;
>
> return 0;
>
Thanks for fixing.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-05-04 16:14 ` David Ahern
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