From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f73.google.com (mail-qv1-f73.google.com [209.85.219.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB35533ADB4 for ; Fri, 21 Nov 2025 08:33:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763713995; cv=none; b=Dfw9S0Q7EOjthspQP4+4Qi2eEVri66FowB+ePFYF5x1eVt0Uz+f1z91oQFZz8SvNnpIdPznltvegrOLyDLZ94b9wYSUtBj03uL/E9kRNrWJfdad6oOWgHDskRE2uC3Y00lphZI8GRVM+YtS8gbVM049NWcKkmGp8wYXisz4rdnE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763713995; c=relaxed/simple; bh=DaYh4eacIzj7fnVYuLbFxktmBe5fYbH300IH3QLNkBE=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=BfD8mL+J3fpoTljZw0M+h1IOH355DwLfGg3BZgZozKhB2f92F2+smkV5pfgKnbjcKMzwapFcnhtyP9V0/Bxfo4L1sLjcHdBEgDzQdPQF9/sUH5YnVrfXbh4N7pRPXNdXHZbzMsKYr7wQn4CrZ2DzFUbf89VokIBGhHHPV9HaPGs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=BZeQsKiw; arc=none smtp.client-ip=209.85.219.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="BZeQsKiw" Received: by mail-qv1-f73.google.com with SMTP id 6a1803df08f44-88041f9e686so55844726d6.1 for ; Fri, 21 Nov 2025 00:33:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1763713993; x=1764318793; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Y+O/PECJ9fW+HIpQreYW08Vwvliv5LsH0C5HRev27oE=; b=BZeQsKiw8g9nkQCXX9xv+j2CFKKak+ggGxXVQw+/w8RZbflsz2AFsUADUpuSCi9w5Y V3ETYhhxtWCYAmI7v22odqQK3s0fYleJAOO2Cmo8yK/Q44GjrghrJv/+mMvSbXKpCbL+ 77FOuXyU5P2lYPjraa89du06V95ONaNjWoj2TXjkhUgDN4QpQEw+axaA5COrpHnYow39 vNC7C2LfnBoVOCEHXOpvTRJSpyTAcjvA6kZBsOfAL5XaJw1Xd4t8hvh3EA2FESs7MNWY w0JVe4x614NDNcYKvfPReQOBhIXrydOSKV3UJ+RbzAkbV8o0Xn2TnXfModBkuik2Q6Mv P/Mg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763713993; x=1764318793; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Y+O/PECJ9fW+HIpQreYW08Vwvliv5LsH0C5HRev27oE=; b=Zh0d15cGv7XFBweXMGySFZZhUdccYRN5DsYW4cZZYIWvG7Rz3pGjmgyYskbH+KEsym /sflTKtliRsGYLV60Y+XzxHqbBp0aRRaPwI1vHIrxwB0FTqWWjxQ9p0RX8BLapzVZzs7 oF0RAi6972S3mXTEIfrVNZPC8e1g9qsygEBoTq2eYMrmjqBWzYVxNxuQmO5AsjEdmrHO wPibCEKkdIAQCDDpB5KF6LMptMMne+G0T6ZbAHOuJtAluVuXZ0HI9tPdaEECD8JLS5UB X1hZr+k8oo8PWCQ+czkTy2QokQIAoNbrBh/TjlOkrbevX9bSSE3w6rLSvkaZ7t+Ry5y5 98Fg== X-Forwarded-Encrypted: i=1; AJvYcCVJwre2sDF3iZ2PgwZn3Ss7Uvy8QYVI/5FmQQPpEN8CG0DX8t0EJ7X43i132ZGEL0g/LPGDh6g=@vger.kernel.org X-Gm-Message-State: AOJu0YzcxdBsbxJPlsFgXyHS5d7RSOD63Gq5eYsxXlsvek/8McljFO9x dyC7vgFKvSHpYl+xpXAYrw8JJWiZeUHJcZxnbOcgDBta00i8iZr/+H5g5ZeNq+QHe7hWvm29f8V p1CMPCmoyOqg+qQ== X-Google-Smtp-Source: AGHT+IEBIuUMOSTo1/GDd4HexicW2Cm/f7InEONKZSe/8dWSFOa4riuKAq2W1e2T9jyZ6pW+jfqkg4KXtyyU+w== X-Received: from qvbpf7.prod.google.com ([2002:a05:6214:4987:b0:880:44cc:d923]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6214:1d06:b0:880:48c6:ad02 with SMTP id 6a1803df08f44-8847c53435fmr21203746d6.52.1763713992891; Fri, 21 Nov 2025 00:33:12 -0800 (PST) Date: Fri, 21 Nov 2025 08:32:53 +0000 In-Reply-To: <20251121083256.674562-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251121083256.674562-1-edumazet@google.com> X-Mailer: git-send-email 2.52.0.460.gd25c4c69ec-goog Message-ID: <20251121083256.674562-12-edumazet@google.com> Subject: [PATCH v3 net-next 11/14] net: annotate a data-race in __dev_xmit_skb() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Jamal Hadi Salim , Cong Wang , Jiri Pirko , "=?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?=" , Kuniyuki Iwashima , Willem de Bruijn , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" q->limit is read locklessly, add a READ_ONCE(). Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption") Signed-off-by: Eric Dumazet --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index 53e2496dc4292284072946fd9131d3f9a0c0af44..10042139dbb054b9a93dfb019477a80263feb029 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4194,7 +4194,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 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; } -- 2.52.0.460.gd25c4c69ec-goog