From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793211345; b=MlxmczRCjY/LnWs3c+96vFHg95eSJODGa0R45D8MhKmnsIXw6jYpTuh0T38ZmHiFihn7 E4wOcS2Ikg07LRImsFpw9tGuf/1UUTDsa6Kf0OKjtrHEgsifVxb86E248n8aK2YQepnMJ BpzVmPFFN/af6GidIdX3IWHzd8mh9AmFZO/+zZmTyGxpVhXth/F/i1gTeGmd0evozZE7I Ypc6SWthew/hCCn38kr2lBixaWnGOZXi4YX8pAzwLfWJagGrGD+wyOYpZbdN/UwK70jcL NrXy/JFifKIpiacc2jFGJ6BA7YfnQlWOGurAmvSOfF7jaEjUyRiCW0etgdJMFKwFYMg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793211345; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=20CFTGHSnyzGjmnH1nBQIsBtPdqDuE3N1bY81N5B07c=; b=aqwqM9wRuLZa1HLemQmwsUPPsS1RN093dceuqqsTEFgwxAnYiaV1/urP+rWXAK0XgnE5 qusJ5jHEAGkE3ZRsqji58ezwv2iMLjgkxQxcMWoWYN+XhNvo0jCW5YgwU1hNBR4DoFplL oT7q69qsLtWlLANeNiw5uZllWYU0YsRPNi4MkhCu9CyTFkOP4tgdAmJmRbikhtBD4APRT OROtBTYSL8Xn2p0/r39Fs5GDu0BXenSkYbL5Fy9UAYH2kT71ETM3WypufUaMSLQpXtpyf HgeOcCy8+eLy1rSI3YuTHuGJysDYNMyiegEWuzu+mak2es5Eh+ZHKw9XwNyi1E3y00w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=KoOd7YIJ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 123DA606A32A; Wed, 28 Oct 2026 18:15:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=KoOd7YIJ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63C551F01825; Wed, 28 Oct 2026 18:15:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793211344; bh=20CFTGHSnyzGjmnH1nBQIsBtPdqDuE3N1bY81N5B07c=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KoOd7YIJ5l6LmVtQjqXtv3tL/7hFiSWelAmGzmoXgRLIOoCoUVbeqqklvjQ0+PycG UxiIQWLhSOHIf7v7ao8H9y/+sfCfncg2GZEYPG0B5s4xbIWDgpZHengooqPqLFjdxD cdK2EWEJzFhYqEohkR+lXI+a6WJVQrzlSWfNEp5o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ido Schimmel , Daehyeon Ko <4ncienth@gmail.com>, Jakub Kicinski Subject: [PATCH 5.15 345/571] ipv4: do not warn on route notification size race Date: Wed, 28 Oct 2026 17:58:12 +0100 Message-ID: <20261028170016.203729766@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daehyeon Ko <4ncienth@gmail.com> commit e02a5b6588161673ef75a4bc5cdfb62bd493374d upstream. Commit 680aea08e78c ("net: ipv4: Emit notification when fib hardware flags are changed") added asynchronous route notifications for hardware flag changes. fib_alias_hw_flags_set() sizes the skb with fib_nlmsg_size() and later fills it with fib_dump_info() while holding only RCU. With nexthop compatibility mode enabled, a concurrent replacement can grow the group between these independent snapshots. fib_dump_info() can then legitimately return -EMSGSIZE, so the warning does not prove a sizing bug. Remove the warning. The existing error path still frees the skb and reports the error to listeners. Fixes: 680aea08e78c ("net: ipv4: Emit notification when fib hardware flags are changed") Reported-by: Ido Schimmel Link: https://lore.kernel.org/netdev/20261004082043.GB92032@shredder/ Suggested-by: Ido Schimmel Cc: stable@vger.kernel.org Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Link: https://patch.msgid.link/b7e203fc5867651cb67ef84aa03e082f0f76008e.1791423190.git.4ncienth@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/ipv4/fib_trie.c | 2 -- 1 file changed, 2 deletions(-) --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -1079,8 +1079,6 @@ void fib_alias_hw_flags_set(struct net * err = fib_dump_info(skb, 0, 0, RTM_NEWROUTE, fri, 0); if (err < 0) { - /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ - WARN_ON(err == -EMSGSIZE); kfree_skb(skb); goto errout; }