From: Eric Dumazet <edumazet@google.com>
Date: Fri, 21 Nov 2025 08:32:53 +0000 (+0000)
Subject: net: annotate a data-race in __dev_xmit_skb()
X-Git-Tag: v6.19-rc1~170^2~83^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4792c3a4c1470202b0d5bf44b6058cb0fb050ba8;p=thirdparty%2Fkernel%2Flinux.git

net: annotate a data-race in __dev_xmit_skb()

q->limit is read locklessly, add a READ_ONCE().

Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-12-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index 53e2496dc4292..10042139dbb05 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4194,7 +4194,7 @@ no_lock_out:
 	do {
 		if (first_n && !defer_count) {
 			defer_count = atomic_long_inc_return(&q->defer_count);
-			if (unlikely(defer_count > q->limit)) {
+			if (unlikely(defer_count > READ_ONCE(q->limit))) {
 				kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP);
 				return NET_XMIT_DROP;
 			}