[PATCH] rtnetlink: Fix error handling in do_setlink()

[PATCH] rtnetlink: Fix error handling in do_setlink()

[David Howells]

Commit c02db8c6290bb992442fec1407643c94cc414375:

	Author:  Chris Wright <chrisw@sous-sol.org>
	Date:    Sun May 16 01:05:45 2010 -0700
	Subject: rtnetlink: make SR-IOV VF interface symmetric

adds broken error handling to do_setlink() in net/core/rtnetlink.c.  The
problem is the following chunk of code:

	if (tb[IFLA_VFINFO_LIST]) {
		struct nlattr *attr;
		int rem;
		nla_for_each_nested(attr, tb[IFLA_VFINFO_LIST], rem) {
			if (nla_type(attr) != IFLA_VF_INFO)
  ---->				goto errout;
			err = do_setvfinfo(dev, attr);
			if (err < 0)
				goto errout;
			modified = 1;
		}
	}

which can get to errout without setting err, resulting in the following error:

net/core/rtnetlink.c: In function 'do_setlink':
net/core/rtnetlink.c:904: warning: 'err' may be used uninitialized in this function

Change the code to return -EINVAL in this case.  Note that this might not be
the appropriate error though.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chris Wright <chrisw@sous-sol.org>
cc: David S. Miller <davem@davemloft.net>
---

 net/core/rtnetlink.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)


diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 31e85d3..56b4157 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1030,8 +1030,10 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 		struct nlattr *attr;
 		int rem;
 		nla_for_each_nested(attr, tb[IFLA_VFINFO_LIST], rem) {
-			if (nla_type(attr) != IFLA_VF_INFO)
+			if (nla_type(attr) != IFLA_VF_INFO) {
+				err = -EINVAL;
 				goto errout;
+			}
 			err = do_setvfinfo(dev, attr);
 			if (err < 0)
 				goto errout;

Re: [PATCH] rtnetlink: Fix error handling in do_setlink()

[Chris Wright]

* David Howells (dhowells@redhat.com) wrote:
> Commit c02db8c6290bb992442fec1407643c94cc414375:
> 
> 	Author:  Chris Wright <chrisw@sous-sol.org>
> 	Date:    Sun May 16 01:05:45 2010 -0700
> 	Subject: rtnetlink: make SR-IOV VF interface symmetric
> 
> adds broken error handling to do_setlink() in net/core/rtnetlink.c.  The
> problem is the following chunk of code:
> 
> 	if (tb[IFLA_VFINFO_LIST]) {
> 		struct nlattr *attr;
> 		int rem;
> 		nla_for_each_nested(attr, tb[IFLA_VFINFO_LIST], rem) {
> 			if (nla_type(attr) != IFLA_VF_INFO)
>   ---->				goto errout;
> 			err = do_setvfinfo(dev, attr);
> 			if (err < 0)
> 				goto errout;
> 			modified = 1;
> 		}
> 	}
> 
> which can get to errout without setting err, resulting in the following error:
> 
> net/core/rtnetlink.c: In function 'do_setlink':
> net/core/rtnetlink.c:904: warning: 'err' may be used uninitialized in this function
> 
> Change the code to return -EINVAL in this case.  Note that this might not be
> the appropriate error though.
> 
> Signed-off-by: David Howells <dhowells@redhat.com>

Acked-by: Chris Wright <chrisw@sous-sol.org>

Thank you David, that's correct.  I have some other pending changes
here, so I don't mind collecting them together.

thanks,
-chris

Re: [PATCH] rtnetlink: Fix error handling in do_setlink()

[David Miller]

From: Chris Wright <chrisw@sous-sol.org>
Date: Fri, 21 May 2010 23:52:12 -0700

> * David Howells (dhowells@redhat.com) wrote:
>> Commit c02db8c6290bb992442fec1407643c94cc414375:
>> 
>> 	Author:  Chris Wright <chrisw@sous-sol.org>
>> 	Date:    Sun May 16 01:05:45 2010 -0700
>> 	Subject: rtnetlink: make SR-IOV VF interface symmetric
>> 
>> adds broken error handling to do_setlink() in net/core/rtnetlink.c.  The
>> problem is the following chunk of code:
>> 
>> 	if (tb[IFLA_VFINFO_LIST]) {
>> 		struct nlattr *attr;
>> 		int rem;
>> 		nla_for_each_nested(attr, tb[IFLA_VFINFO_LIST], rem) {
>> 			if (nla_type(attr) != IFLA_VF_INFO)
>>   ---->				goto errout;
>> 			err = do_setvfinfo(dev, attr);
>> 			if (err < 0)
>> 				goto errout;
>> 			modified = 1;
>> 		}
>> 	}
>> 
>> which can get to errout without setting err, resulting in the following error:
>> 
>> net/core/rtnetlink.c: In function 'do_setlink':
>> net/core/rtnetlink.c:904: warning: 'err' may be used uninitialized in this function
>> 
>> Change the code to return -EINVAL in this case.  Note that this might not be
>> the appropriate error though.
>> 
>> Signed-off-by: David Howells <dhowells@redhat.com>
> 
> Acked-by: Chris Wright <chrisw@sous-sol.org>

Applied, thanks.