From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 058883B6BFE; Sat, 17 Oct 2026 17:12:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792257147; cv=none; b=At0hVr1mEE24hV5pIiWVJA9EO083CKAJPQJ4TjV6xstG2Nnq0+VhzIwAwxZLMQ0jVspGL4elQQtkMhtQpLEHmXmvLjXhrepZMVfm/z2nYkypQDsZGAl2KXmpVLAvpGigrhRLUBhwRlv7DUYKr2pKdIkEu4PrRopvZnzHc8tGHTs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792257147; c=relaxed/simple; bh=JvffVdUaoTM+GnPxVQE6SVg6AiTgdGQNmxd3lPYqBNo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gTNGFKhYKktWFeMuMVitbn4UplbBzMfrBnyJlAq/wUAqh4M/aDokQ8d5yHYvwvOeGcVersM41BEVJgRb1ZrIumLRC/a8nENjcBH43mhsEs+OWOjK4Yze5pFhbLtT0Vi0lNXlWaDTsUP86fTfGthPaW5iU2jSvGnn6iNsPfhMo7I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VfVxHdhY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="VfVxHdhY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 511081F000C4; Sat, 17 Oct 2026 17:12:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792257145; bh=Z5E0ZJAfdpSECoM3fO/0wsUvF8krgaYp8IYDoIXbZ5Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VfVxHdhYQ5FiU+bA1wt47qSdONuWMmw/35lZ1DC1t3XmV8cn2NK7UCBS0aA+5t7/o UQ6MIisr0t4+7YnG6bUFrz2BxHdRzxVuHzqawyRk+oxYyCRNdylD8mm6sbM2P1vEmN SdDEzx2W45HxOgywM0Ux9cz3ZGrKtP8afiCdjDFw= 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 6.6 0465/1674] ipv4: do not warn on route notification size race Date: Sat, 17 Oct 2026 17:45:37 +0200 Message-ID: <20261017160443.056180884@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-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 @@ -1084,8 +1084,6 @@ 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; }