Patch "netdev: let netlink core handle -EMSGSIZE errors" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    netdev: let netlink core handle -EMSGSIZE errors

to the 6.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netdev-let-netlink-core-handle-emsgsize-errors.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit f776e28a960ff183e2d35cf461c32a33bcbeb0c6
Author: Jakub Kicinski <kuba@xxxxxxxxxx>
Date:   Sat Mar 2 21:24:07 2024 -0800

    netdev: let netlink core handle -EMSGSIZE errors
    
    [ Upstream commit 0b11b1c5c320555483e8a94c44549db24c289987 ]
    
    Previous change added -EMSGSIZE handling to af_netlink, we don't
    have to hide these errors any longer.
    
    Theoretically the error handling changes from:
     if (err == -EMSGSIZE)
    to
     if (err == -EMSGSIZE && skb->len)
    
    everywhere, but in practice it doesn't matter.
    All messages fit into NLMSG_GOODSIZE, so overflow of an empty
    skb cannot happen.
    
    Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index fd98936da3aec..918b109e0cf40 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -152,10 +152,7 @@ int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 	rtnl_unlock();
 
-	if (err != -EMSGSIZE)
-		return err;
-
-	return skb->len;
+	return err;
 }
 
 static int
@@ -287,10 +284,7 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 	rtnl_unlock();
 
-	if (err != -EMSGSIZE)
-		return err;
-
-	return skb->len;
+	return err;
 }
 
 static int
@@ -463,10 +457,7 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 	rtnl_unlock();
 
-	if (err != -EMSGSIZE)
-		return err;
-
-	return skb->len;
+	return err;
 }
 
 static int netdev_genl_netdevice_event(struct notifier_block *nb,
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 278294aca66ab..3a3277ba167b1 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -103,8 +103,6 @@ netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
 	mutex_unlock(&page_pools_lock);
 	rtnl_unlock();
 
-	if (skb->len && err == -EMSGSIZE)
-		return skb->len;
 	return err;
 }