This is a note to let you know that I've just added the patch titled
xfrm: Fix unregister netdevice hang on hardware offload.
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:
xfrm-fix-unregister-netdevice-hang-on-hardware-offlo.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 27e9d16a6bef5c95218546e3e74b556582a262e4
Author: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Date: Thu Jun 20 08:47:24 2024 +0200
xfrm: Fix unregister netdevice hang on hardware offload.
[ Upstream commit 07b87f9eea0c30675084d50c82532d20168da009 ]
When offloading xfrm states to hardware, the offloading
device is attached to the skbs secpath. If a skb is free
is deferred, an unregister netdevice hangs because the
netdevice is still refcounted.
Fix this by removing the netdevice from the xfrm states
when the netdevice is unregistered. To find all xfrm states
that need to be cleared we add another list where skbs
linked to that are unlinked from the lists (deleted)
but not yet freed.
Fixes: d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API")
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index a3fd2cfed5e33..b280e7c460116 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -176,7 +176,10 @@ struct xfrm_state {
struct hlist_node gclist;
struct hlist_node bydst;
};
- struct hlist_node bysrc;
+ union {
+ struct hlist_node dev_gclist;
+ struct hlist_node bysrc;
+ };
struct hlist_node byspi;
struct hlist_node byseq;
@@ -1584,7 +1587,7 @@ int xfrm_state_check_expire(struct xfrm_state *x);
static inline void xfrm_dev_state_update_curlft(struct xfrm_state *x)
{
struct xfrm_dev_offload *xdo = &x->xso;
- struct net_device *dev = xdo->dev;
+ struct net_device *dev = READ_ONCE(xdo->dev);
if (x->xso.type != XFRM_DEV_OFFLOAD_PACKET)
return;
@@ -1943,13 +1946,16 @@ int xfrm_dev_policy_add(struct net *net, struct xfrm_policy *xp,
struct xfrm_user_offload *xuo, u8 dir,
struct netlink_ext_ack *extack);
bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x);
+void xfrm_dev_state_delete(struct xfrm_state *x);
+void xfrm_dev_state_free(struct xfrm_state *x);
static inline void xfrm_dev_state_advance_esn(struct xfrm_state *x)
{
struct xfrm_dev_offload *xso = &x->xso;
+ struct net_device *dev = READ_ONCE(xso->dev);
- if (xso->dev && xso->dev->xfrmdev_ops->xdo_dev_state_advance_esn)
- xso->dev->xfrmdev_ops->xdo_dev_state_advance_esn(x);
+ if (dev && dev->xfrmdev_ops->xdo_dev_state_advance_esn)
+ dev->xfrmdev_ops->xdo_dev_state_advance_esn(x);
}
static inline bool xfrm_dst_offload_ok(struct dst_entry *dst)
@@ -1970,28 +1976,6 @@ static inline bool xfrm_dst_offload_ok(struct dst_entry *dst)
return false;
}
-static inline void xfrm_dev_state_delete(struct xfrm_state *x)
-{
- struct xfrm_dev_offload *xso = &x->xso;
-
- if (xso->dev)
- xso->dev->xfrmdev_ops->xdo_dev_state_delete(x);
-}
-
-static inline void xfrm_dev_state_free(struct xfrm_state *x)
-{
- struct xfrm_dev_offload *xso = &x->xso;
- struct net_device *dev = xso->dev;
-
- if (dev && dev->xfrmdev_ops) {
- if (dev->xfrmdev_ops->xdo_dev_state_free)
- dev->xfrmdev_ops->xdo_dev_state_free(x);
- xso->dev = NULL;
- xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
- netdev_put(dev, &xso->dev_tracker);
- }
-}
-
static inline void xfrm_dev_policy_delete(struct xfrm_policy *x)
{
struct xfrm_dev_offload *xdo = &x->xdo;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index bda5327bf34df..e5308bb75eea2 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -49,6 +49,7 @@ static struct kmem_cache *xfrm_state_cache __ro_after_init;
static DECLARE_WORK(xfrm_state_gc_work, xfrm_state_gc_task);
static HLIST_HEAD(xfrm_state_gc_list);
+static HLIST_HEAD(xfrm_state_dev_gc_list);
static inline bool xfrm_state_hold_rcu(struct xfrm_state __rcu *x)
{
@@ -214,6 +215,7 @@ static DEFINE_SPINLOCK(xfrm_state_afinfo_lock);
static struct xfrm_state_afinfo __rcu *xfrm_state_afinfo[NPROTO];
static DEFINE_SPINLOCK(xfrm_state_gc_lock);
+static DEFINE_SPINLOCK(xfrm_state_dev_gc_lock);
int __xfrm_state_delete(struct xfrm_state *x);
@@ -683,6 +685,40 @@ struct xfrm_state *xfrm_state_alloc(struct net *net)
}
EXPORT_SYMBOL(xfrm_state_alloc);
+#ifdef CONFIG_XFRM_OFFLOAD
+void xfrm_dev_state_delete(struct xfrm_state *x)
+{
+ struct xfrm_dev_offload *xso = &x->xso;
+ struct net_device *dev = READ_ONCE(xso->dev);
+
+ if (dev) {
+ dev->xfrmdev_ops->xdo_dev_state_delete(x);
+ spin_lock_bh(&xfrm_state_dev_gc_lock);
+ hlist_add_head(&x->dev_gclist, &xfrm_state_dev_gc_list);
+ spin_unlock_bh(&xfrm_state_dev_gc_lock);
+ }
+}
+
+void xfrm_dev_state_free(struct xfrm_state *x)
+{
+ struct xfrm_dev_offload *xso = &x->xso;
+ struct net_device *dev = READ_ONCE(xso->dev);
+
+ if (dev && dev->xfrmdev_ops) {
+ spin_lock_bh(&xfrm_state_dev_gc_lock);
+ if (!hlist_unhashed(&x->dev_gclist))
+ hlist_del(&x->dev_gclist);
+ spin_unlock_bh(&xfrm_state_dev_gc_lock);
+
+ if (dev->xfrmdev_ops->xdo_dev_state_free)
+ dev->xfrmdev_ops->xdo_dev_state_free(x);
+ WRITE_ONCE(xso->dev, NULL);
+ xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
+ netdev_put(dev, &xso->dev_tracker);
+ }
+}
+#endif
+
void __xfrm_state_destroy(struct xfrm_state *x, bool sync)
{
WARN_ON(x->km.state != XFRM_STATE_DEAD);
@@ -848,6 +884,9 @@ EXPORT_SYMBOL(xfrm_state_flush);
int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_valid)
{
+ struct xfrm_state *x;
+ struct hlist_node *tmp;
+ struct xfrm_dev_offload *xso;
int i, err = 0, cnt = 0;
spin_lock_bh(&net->xfrm.xfrm_state_lock);
@@ -857,8 +896,6 @@ int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_vali
err = -ESRCH;
for (i = 0; i <= net->xfrm.state_hmask; i++) {
- struct xfrm_state *x;
- struct xfrm_dev_offload *xso;
restart:
hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
xso = &x->xso;
@@ -868,6 +905,8 @@ int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_vali
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
err = xfrm_state_delete(x);
+ xfrm_dev_state_free(x);
+
xfrm_audit_state_delete(x, err ? 0 : 1,
task_valid);
xfrm_state_put(x);
@@ -884,6 +923,24 @@ int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_vali
out:
spin_unlock_bh(&net->xfrm.xfrm_state_lock);
+
+ spin_lock_bh(&xfrm_state_dev_gc_lock);
+restart_gc:
+ hlist_for_each_entry_safe(x, tmp, &xfrm_state_dev_gc_list, dev_gclist) {
+ xso = &x->xso;
+
+ if (xso->dev == dev) {
+ spin_unlock_bh(&xfrm_state_dev_gc_lock);
+ xfrm_dev_state_free(x);
+ spin_lock_bh(&xfrm_state_dev_gc_lock);
+ goto restart_gc;
+ }
+
+ }
+ spin_unlock_bh(&xfrm_state_dev_gc_lock);
+
+ xfrm_flush_gc();
+
return err;
}
EXPORT_SYMBOL(xfrm_dev_state_flush);
