[PATCH net v2] net: ncsi: fix skb leak in error paths

[PATCH net v2] net: ncsi: fix skb leak in error paths

[Jian Zhang]

Early return paths in NCSI RX and AEN handlers fail to release
the received skb, resulting in a memory leak.

Specifically, ncsi_aen_handler() returns on invalid AEN packets
without consuming the skb. Similarly, ncsi_rcv_rsp() exits early
when failing to resolve the NCSI device, response handler, or
request, leaving the skb unfreed.

CC: stable@vger.kernel.org
Fixes: 7a82ecf4cfb8 ("net/ncsi: NCSI AEN packet handler")
Fixes: 138635cc27c9 ("net/ncsi: NCSI response packet handler")
Signed-off-by: Jian Zhang <zhangjian.3032@bytedance.com>
---
Changes in v2:
- use meaningful label
- use kfree_skb to free skb in error paths
- add Fixes label

v1: https://lore.kernel.org/all/20260302054629.1347119-1-zhangjian.3032@bytedance.com/
---
 net/ncsi/ncsi-aen.c |  3 ++-
 net/ncsi/ncsi-rsp.c | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/net/ncsi/ncsi-aen.c b/net/ncsi/ncsi-aen.c
index 62fb1031763d..040a31557201 100644
--- a/net/ncsi/ncsi-aen.c
+++ b/net/ncsi/ncsi-aen.c
@@ -224,7 +224,8 @@ int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
 	if (!nah) {
 		netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
 			    h->type);
-		return -ENOENT;
+		ret = -ENOENT;
+		goto out;
 	}
 
 	ret = ncsi_validate_aen_pkt(h, nah->payload);
diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
index 271ec6c3929e..fbd84bc8026a 100644
--- a/net/ncsi/ncsi-rsp.c
+++ b/net/ncsi/ncsi-rsp.c
@@ -1176,8 +1176,10 @@ int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
 	/* Find the NCSI device */
 	nd = ncsi_find_dev(orig_dev);
 	ndp = nd ? TO_NCSI_DEV_PRIV(nd) : NULL;
-	if (!ndp)
-		return -ENODEV;
+	if (!ndp) {
+		ret = -ENODEV;
+		goto err_free_skb;
+	}
 
 	/* Check if it is AEN packet */
 	hdr = (struct ncsi_pkt_hdr *)skb_network_header(skb);
@@ -1199,7 +1201,8 @@ int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
 	if (!nrh) {
 		netdev_err(nd->dev, "Received unrecognized packet (0x%x)\n",
 			   hdr->type);
-		return -ENOENT;
+		ret = -ENOENT;
+		goto err_free_skb;
 	}
 
 	/* Associate with the request */
@@ -1207,7 +1210,8 @@ int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
 	nr = &ndp->requests[hdr->id];
 	if (!nr->used) {
 		spin_unlock_irqrestore(&ndp->lock, flags);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto err_free_skb;
 	}
 
 	nr->rsp = skb;
@@ -1261,4 +1265,8 @@ int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
 out:
 	ncsi_free_request(nr);
 	return ret;
+
+err_free_skb:
+	kfree_skb(skb);
+	return ret;
 }
-- 
2.20.1

Re: [PATCH net v2] net: ncsi: fix skb leak in error paths

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu,  5 Mar 2026 14:06:55 +0800 you wrote:
> Early return paths in NCSI RX and AEN handlers fail to release
> the received skb, resulting in a memory leak.
> 
> Specifically, ncsi_aen_handler() returns on invalid AEN packets
> without consuming the skb. Similarly, ncsi_rcv_rsp() exits early
> when failing to resolve the NCSI device, response handler, or
> request, leaving the skb unfreed.
> 
> [...]

Here is the summary with links:
  - [net,v2] net: ncsi: fix skb leak in error paths
    https://git.kernel.org/netdev/net/c/5c3398a54266

You are awesome, thank you!
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