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rtnetlink: fix link attribute validation with IFLA_GROUP

PATCH Applied Patrick McHardy 3 participants 3 messages Jan 20, 2011 – Jan 21, 2011

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Patrick McHardy

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#0 lore raw

PATCH 1/1 rtnetlink: fix link attribute validation with IFLA_GROUP

Fix a few semantic problems with the new IFLA_GROUP attribute.

Vlad, could you please give this is a try to see whether it still behaves as expected?

commit e4b31d565a45e06ed2e51a005f5c00ff1d00725c

Author: Patrick McHardy <[email protected]>
Date:   Thu Jan 20 13:55:25 2011 +0100

rtnetlink: fix link attribute validation with IFLA_GROUP

rtnl_group_changelink() is invoked by rtnl_newlink() before the link attributes have been validated. Additionally the group changes are performed even if NLM_F_CREATE is specified and a new link is created, while more reasonable semantics would be to set the group value on the newly created link.

Fix both problems by moving the rtnl_group_changelink() invocation down to the handling of non-existant links without NLM_F_CREATE() and add a dev_set_group() call to rtnl_create_link().

Signed-off-by Patrick McHardy <[email protected]>
net/core/rtnetlink.c +8 -5
index a0b2eeb..310eb80 100644
@@ -1548,6 +1548,8 @@ struct net_device *rtnl_create_link(struct net *src_net, struct net *net,
 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
 	if (tb[IFLA_LINKMODE])
 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
+	if (tb[IFLA_GROUP])
+		dev_set_group(dev, nla_get_u32(tb[IFLA_GROUP]));
 
 	return dev;
 

@@ -1606,10 +1608,6 @@ replay:
 	else {
 		if (ifname[0])
 			dev = __dev_get_by_name(net, ifname);
-		else if (tb[IFLA_GROUP])
-			return rtnl_group_changelink(net,
-					nla_get_u32(tb[IFLA_GROUP]),
-					ifm, tb);
 		else
 			dev = NULL;
 	}

@@ -1676,8 +1674,13 @@ replay:
 			return do_setlink(dev, ifm, tb, ifname, modified);
 		}
 
-		if (!(nlh->nlmsg_flags & NLM_F_CREATE))
+		if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
+			if (ifm->ifi_index == 0 && tb[IFLA_GROUP])
+				return rtnl_group_changelink(net,
+						nla_get_u32(tb[IFLA_GROUP]),
+						ifm, tb);
 			return -ENODEV;
+		}
 
 		if (ifm->ifi_index)
 			return -EOPNOTSUPP;
Acked-by on v1 1/1
#1 lore raw
Quoted 17 lines · Patrick McHardy

Fix a few semantic problems with the new IFLA_GROUP attribute.

Vlad, could you please give this is a try to see whether it still behaves as expected?

commit e4b31d565a45e06ed2e51a005f5c00ff1d00725c

Author: Patrick McHardy <[email protected]>
Date:   Thu Jan 20 13:55:25 2011 +0100

rtnetlink: fix link attribute validation with IFLA_GROUP

rtnl_group_changelink() is invoked by rtnl_newlink() before the link attributes have been validated. Additionally the group changes are performed even if NLM_F_CREATE is specified and a new link is created, while more reasonable semantics would be to set the group value on the newly created link.

Quoted 5 lines

Fix both problems by moving the rtnl_group_changelink() invocation down to the handling of non-existant links without NLM_F_CREATE() and add a dev_set_group() call to rtnl_create_link().

Signed-off-by Patrick McHardy <[email protected]>
Acked-by Vlad Dogaru <[email protected]>

This looks OK and behaves as before. Thanks for taking the time to look through it, the new semantics do seem saner.

There is a slight difference, though: in the (yet unapplied) iproute2 patch, ifi_index is set to -1 and kernel space checks that it is <= 0; your patch checks for == 0. I will update the iproute2 patches with setting ifi_index to 0 (and other changes) and resubmit them.

maintainer Applied
#2 lore raw

From: Vlad Dogaru <[email protected]>
Date: Thu, 20 Jan 2011 18:09:10 +0200

Quoted 18 lines · Patrick McHardy
Quoted 17 lines

Fix a few semantic problems with the new IFLA_GROUP attribute.

Vlad, could you please give this is a try to see whether it still behaves as expected?

commit e4b31d565a45e06ed2e51a005f5c00ff1d00725c

Author: Patrick McHardy <[email protected]>
Date:   Thu Jan 20 13:55:25 2011 +0100

rtnetlink: fix link attribute validation with IFLA_GROUP

rtnl_group_changelink() is invoked by rtnl_newlink() before the link attributes have been validated. Additionally the group changes are performed even if NLM_F_CREATE is specified and a new link is created, while more reasonable semantics would be to set the group value on the newly created link.

Quoted 7 lines
Quoted 5 lines

Fix both problems by moving the rtnl_group_changelink() invocation down to the handling of non-existant links without NLM_F_CREATE() and add a dev_set_group() call to rtnl_create_link().

Signed-off-by Patrick McHardy <[email protected]>
Acked-by Vlad Dogaru <[email protected]>

Applied, thanks everyone.