From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 04FB12772E for ; Wed, 20 May 2026 06:39:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779259172; cv=none; b=c46eIv/ysVOygsndhbCe/NYYhodWPR1CtRRQyORx+P1z4K+0djnT/RzCFz+0ZMrSK3GY8FviBPz+tJwbSat3fQ3mvnFsxhShwd00/IzeNdT6G8fy6otib2lYEmqFnCBFx1C8jAMebEVhlGS4OWqLw3y+JTTtr86XIN9aWWxW3TQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779259172; c=relaxed/simple; bh=G9YObRbn7FyUP+d8PJ+dI4Tvdp/EUY0J8aKHGnzu3f0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QZsxN8FqrdswHOyJl82WPUSF1aB5G78Pf8givCnK9OgF1yc643Bjo2YDxext6IfDFc5jf0uWoVLlIETf+QZvprKL0oPd4Vly814/NVxoLdRfhswQt3tZLKLQd3+ghsB756AKwC64lIE5smjtQ/zsDPpfu5mbN+RY/dUGYgrvcng= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=rVFK+2oo; arc=none smtp.client-ip=91.218.175.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="rVFK+2oo" Message-ID: <7cf35e75-28a6-40b4-86d5-82b0aa9773bd@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779259168; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1VS63f0SQXp0YYrkvpu+Ut5OR4TyOTvu00sYK25+llw=; b=rVFK+2ooCe+s1qUlIqsyYfg2l3g7T249B6Cw4prECA3od3StnQ8H4g3q64UorzEj8SsiKJ jEboaAeRQ0x7mIzvJQ181P0LJOfsKCNsacEX331SnKe5aIrdGEhlOHMZuo1q/zzfAQpNf2 lpumkI0Z0bvtgPDkxGE9xtBz/Qo1WTo= Date: Wed, 20 May 2026 14:39:20 +0800 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH net] ipv4: use WARN_ON_ONCE() in ip_rt_bug() To: Eric Dumazet , "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Ido Schimmel , David Ahern , netdev@vger.kernel.org, eric.dumazet@gmail.com References: <20260519193248.4018872-1-edumazet@google.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Jiayuan Chen In-Reply-To: <20260519193248.4018872-1-edumazet@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 5/20/26 3:32 AM, Eric Dumazet wrote: > It turns out ip_rt_bug() can be called more than expected. > > syzbot will still panic (because of panic_on_warn=1), but non debug > kernels will no longer die while repeating stack traces on the console. > > Fixes: c378a9c019cf ("ipv4: Give backtrace in ip_rt_bug().") > Signed-off-by: Eric Dumazet > --- > net/ipv4/route.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/route.c b/net/ipv4/route.c > index bc1296f0ea69b0705e00e547a0d550129e03326a..3d62d45d84bda986db8b3592c0c7f5c81da3fb7e 100644 > --- a/net/ipv4/route.c > +++ b/net/ipv4/route.c > @@ -1272,7 +1272,7 @@ static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) > __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, > skb->dev ? skb->dev->name : "?"); > kfree_skb(skb); > - WARN_ON(1); > + WARN_ON_ONCE(1); > return 0; > } > Reviewed-by: Jiayuan Chen Recently I backported one missing patch to stable because of excessive ip_rt_bug() prints. So I think it is reasonable to carry a Fixes tag for backporting. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-6.6.y&id=da54b3039d436227deebbc202cefea63bd318a38