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 0027139D3D0; Tue, 13 Oct 2026 12:48:04 +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=1791895686; cv=none; b=EVuYe60gS7GbUQrryCj52ICv+j13mTqEjyxWVLbUrWtRIZ3oXxo1EcJ10lwo1k3QCp94B1I5MsJd/OM4imlpKMg+D4s07o0t2Ku4+MM8sqSV8gZVkAlrF4WyjNO6soL2rFXGHsytzp+vVolK2ARpo8Q3urSDn8q50X6QTVxjres= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791895686; c=relaxed/simple; bh=tfEysrGUlX5Q/VYAsBfL0Af9ISSpeA2Q5Eg0PXp5md4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LGX5PUiDVHg0cFThjtPKc1E+y6G1PHFM3sHG4Iq6CsvA9/jCRXVHWaLSdgNt6XJh/QeosbKNb9H5wiQBbGUFXdw1xgER4mvEX79njoIFpnVysBX/2dlc6pAoPzcWt/i+WYEuYJ38vWpVPZqkZ/siIzXfHcKbz+T4N5bg8kkNEik= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Dc7X337W; 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="Dc7X337W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E8CA1F000FF; Tue, 13 Oct 2026 12:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791895684; bh=TJMX+kcJLMe+nwZZ3rA92bbw0RhpQlbiz5ld7IHsxa4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Dc7X337WInSZE5S009lAsK3VV1EiZVgV3iZf6+0uDImAGA5yUQk848bhUlvgUF6PK mHY50C7ThJB3hO78ip9raUXvjmFn4se6fUlMKYQ+kXz70/UQpHNIXPKhC1QqPjoUKK rLOxVXiBHcnDwHYJjCoAa1ZOPqM10aNwcUvgJWuY= 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 6.12 357/497] ipv4: do not warn on route notification size race Date: Tue, 13 Oct 2026 13:38:44 +0200 Message-ID: <20261013112916.379865570@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112907.864180619@linuxfoundation.org> References: <20261013112907.864180619@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 6.12-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 @@ -1085,8 +1085,6 @@ 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; }