[PATCH 01/10] xfrm: propagate -EINPROGRESS from validate_xmit_xfrm()
From: Steffen Klassert <steffen.klassert@secunet.com>
Date: 2026-07-10 09:04:02
Subsystem:
networking [general], networking [ipsec], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Steffen Klassert, Herbert Xu, Linus Torvalds
From: Petr Wozniak <redacted>
validate_xmit_xfrm() returns NULL both when a packet is dropped and
when it is stolen by async crypto (-EINPROGRESS from ->xmit()).
Callers cannot distinguish the two cases.
f53c723902d1 ("net: Add asynchronous callbacks for xfrm on layer 2.")
changed the semantics of a NULL return from "dropped" to "stolen or
dropped", but __dev_queue_xmit() was not updated. On virtual/bridge
interfaces (noqueue qdisc) __dev_queue_xmit() initialises rc=-ENOMEM
and jumps to out: when skb is NULL, returning -ENOMEM to the caller
even though the packet will be delivered correctly via xfrm_dev_resume().
Return ERR_PTR(-EINPROGRESS) from validate_xmit_xfrm() for the async
case so callers can tell it apart from a real drop. Update
__dev_queue_xmit() to handle ERR_PTR(-EINPROGRESS) from
validate_xmit_skb() correctly. Update validate_xmit_skb_list() to
use IS_ERR_OR_NULL() so that ERR_PTR(-EINPROGRESS) is not mistakenly
added to the transmitted list.
Fixes: f53c723902d1 ("net: Add asynchronous callbacks for xfrm on layer 2.")
Suggested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Petr Wozniak <redacted>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
net/core/dev.c | 10 ++++++++--
net/xfrm/xfrm_device.c | 4 ++--
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index 4b3d5cfdf6e0..5933c5dab09e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -4018,6 +4018,9 @@ static struct sk_buff *validate_xmit_unreadable_skb(struct sk_buff *skb, return NULL; } +/* Returns the skb on success, NULL if dropped, or ERR_PTR(-EINPROGRESS) + * if stolen by async xfrm crypto (delivered via xfrm_dev_resume()). + */ static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again) { netdev_features_t features;
@@ -4089,7 +4092,7 @@ struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *d skb->prev = skb; skb = validate_xmit_skb(skb, dev, again); - if (!skb) + if (IS_ERR_OR_NULL(skb)) continue; if (!head)
@@ -4860,8 +4863,11 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) goto recursion_alert; skb = validate_xmit_skb(skb, dev, &again); - if (!skb) + if (IS_ERR_OR_NULL(skb)) { + if (PTR_ERR(skb) == -EINPROGRESS) + rc = NET_XMIT_SUCCESS; goto out; + } HARD_TX_LOCK(dev, txq, cpu);
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 630f3dd31cc5..19c77f09acc9 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c@@ -182,7 +182,7 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur err = x->type_offload->xmit(x, skb, esp_features); if (err) { if (err == -EINPROGRESS) - return NULL; + return ERR_PTR(-EINPROGRESS); XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); kfree_skb(skb);
@@ -224,7 +224,7 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur pskb = skb2; } - return skb; + return skb ? skb : ERR_PTR(-EINPROGRESS); } EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
--
2.43.0