This is a note to let you know that I've just added the patch titled
netpoll: Ensure clean state on setup failures
to the 6.6-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:
netpoll-ensure-clean-state-on-setup-failures.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c0c013d6e5411583dde34d59b2d2b44b70eb6ba5
Author: Breno Leitao <leitao@xxxxxxxxxx>
Date: Thu Aug 22 04:10:47 2024 -0700
netpoll: Ensure clean state on setup failures
[ Upstream commit ae5a0456e0b4cfd7e61619e55251ffdf1bc7adfb ]
Modify netpoll_setup() and __netpoll_setup() to ensure that the netpoll
structure (np) is left in a clean state if setup fails for any reason.
This prevents carrying over misconfigured fields in case of partial
setup success.
Key changes:
- np->dev is now set only after successful setup, ensuring it's always
NULL if netpoll is not configured or if netpoll_setup() fails.
- np->local_ip is zeroed if netpoll setup doesn't complete successfully.
- Added DEBUG_NET_WARN_ON_ONCE() checks to catch unexpected states.
- Reordered some operations in __netpoll_setup() for better logical flow.
These changes improve the reliability of netpoll configuration, since it
assures that the structure is fully initialized or totally unset.
Suggested-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
Link: https://patch.msgid.link/20240822111051.179850-2-leitao@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 55bcacf67df3b..e082139004093 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -626,12 +626,9 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
const struct net_device_ops *ops;
int err;
- np->dev = ndev;
- strscpy(np->dev_name, ndev->name, IFNAMSIZ);
-
if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
np_err(np, "%s doesn't support polling, aborting\n",
- np->dev_name);
+ ndev->name);
err = -ENOTSUPP;
goto out;
}
@@ -649,7 +646,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
refcount_set(&npinfo->refcnt, 1);
- ops = np->dev->netdev_ops;
+ ops = ndev->netdev_ops;
if (ops->ndo_netpoll_setup) {
err = ops->ndo_netpoll_setup(ndev, npinfo);
if (err)
@@ -660,6 +657,8 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
refcount_inc(&npinfo->refcnt);
}
+ np->dev = ndev;
+ strscpy(np->dev_name, ndev->name, IFNAMSIZ);
npinfo->netpoll = np;
/* last thing to do is link it to the net device structure */
@@ -677,6 +676,7 @@ EXPORT_SYMBOL_GPL(__netpoll_setup);
int netpoll_setup(struct netpoll *np)
{
struct net_device *ndev = NULL;
+ bool ip_overwritten = false;
struct in_device *in_dev;
int err;
@@ -741,6 +741,7 @@ int netpoll_setup(struct netpoll *np)
}
np->local_ip.ip = ifa->ifa_local;
+ ip_overwritten = true;
np_info(np, "local IP %pI4\n", &np->local_ip.ip);
} else {
#if IS_ENABLED(CONFIG_IPV6)
@@ -757,6 +758,7 @@ int netpoll_setup(struct netpoll *np)
!!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
continue;
np->local_ip.in6 = ifp->addr;
+ ip_overwritten = true;
err = 0;
break;
}
@@ -787,6 +789,9 @@ int netpoll_setup(struct netpoll *np)
return 0;
put:
+ DEBUG_NET_WARN_ON_ONCE(np->dev);
+ if (ip_overwritten)
+ memset(&np->local_ip, 0, sizeof(np->local_ip));
netdev_put(ndev, &np->dev_tracker);
unlock:
rtnl_unlock();
