From c16f74dc1d75d0e2e7670076d5375deda110ebeb Mon Sep 17 00:00:00 2001 From: Zhengchuan Liang Date: Fri, 22 May 2026 17:31:55 +0800 Subject: [PATCH] xfrm: input: hold netns during deferred transport reinjection Transport-mode reinjection stores a struct net pointer in skb->cb and uses it later from xfrm_trans_reinject(). That pointer must stay valid until the deferred callback runs. Take a netns reference when queueing deferred reinjection work and drop it after the callback completes. Use maybe_get_net() so the queueing path does not revive a namespace that is already being torn down. This keeps the existing workqueue design and fixes the netns lifetime handling in one place for all users of xfrm_trans_queue_net(). Fixes: 7b3801927e52 ("xfrm: introduce xfrm_trans_queue_net") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Xin Liu Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zhengchuan Liang Signed-off-by: Ren Wei Assisted-by: Codex:gpt-5.4 Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_input.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index f65291eba1f6..e4c2cd24936d 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -797,9 +797,12 @@ static void xfrm_trans_reinject(struct work_struct *work) spin_unlock_bh(&trans->queue_lock); local_bh_disable(); - while ((skb = __skb_dequeue(&queue))) - XFRM_TRANS_SKB_CB(skb)->finish(XFRM_TRANS_SKB_CB(skb)->net, - NULL, skb); + while ((skb = __skb_dequeue(&queue))) { + struct net *net = XFRM_TRANS_SKB_CB(skb)->net; + + XFRM_TRANS_SKB_CB(skb)->finish(net, NULL, skb); + put_net(net); + } local_bh_enable(); } @@ -808,6 +811,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb, struct sk_buff *)) { struct xfrm_trans_tasklet *trans; + struct net *hold_net; trans = this_cpu_ptr(&xfrm_trans_tasklet); @@ -816,8 +820,12 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb, BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb)); + hold_net = maybe_get_net(net); + if (!hold_net) + return -ENODEV; + XFRM_TRANS_SKB_CB(skb)->finish = finish; - XFRM_TRANS_SKB_CB(skb)->net = net; + XFRM_TRANS_SKB_CB(skb)->net = hold_net; spin_lock_bh(&trans->queue_lock); __skb_queue_tail(&trans->queue, skb); spin_unlock_bh(&trans->queue_lock);