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 281EF4F0546; Tue, 13 Oct 2026 11:45:55 +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=1791891957; cv=none; b=OFdWZEAJK0pu3quVjy1IZU2m8ysouShP9tlblCYufl+Lqp+oxR5sNEjO0esL8WipCGIoZUtDW08SWc+NeyedTme6BO3dXqxd9n69O6OdGiThqsiQ87hHptkaZgEqnQWiT2OfewBMyr6RTlwkCxiqIfLE+8xw5jSeMdyDF7lNvL8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791891957; c=relaxed/simple; bh=BAXfVSHul4PBQ9THPgvK8HM3c0rj+btP60XpNL2m1Z8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JvtWiUVIbDddIE3IRscYxuhsZIWiSwB7NulARGwl3bxSiyZ5+WnBNDbUJMHKC4WdDZAduBK2OkuUux24JzXOvGm/hNPxloEAEkpUyC1dGYDQCmKO32YBI48QWE+lakI6cqs4M802MX26FlJf3tHfKfjZ8KL9FZ0sLr1eTfTY3Ew= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PyZ/+oqa; 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="PyZ/+oqa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2FA461F000FF; Tue, 13 Oct 2026 11:45:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791891955; bh=aZeFBig4gsNSP0S1iZtNutsXd7tswssnwaRL3lgzILs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PyZ/+oqaAuOxutkYMeEhZcPMpLvvlgLC6l5eBzUfC4zqVj+gIz5XyAuCXI9umshN8 Q3pRe0pRz+0aG12uM3WNSk95aMEkCGxmA2Ru/Ri3kHwPZ3EJdsRF1JSS2FeV29HdKk AKIq/0S4PkwIUKKFdDxHsseGKqkgrvhUzPWgEMMU= 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 7.2 013/281] ipv4: do not warn on route notification size race Date: Tue, 13 Oct 2026 13:35:29 +0200 Message-ID: <20261013112855.371107730@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112855.045212108@linuxfoundation.org> References: <20261013112855.045212108@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 7.2-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; }