From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 04C70C54ED0 for ; Thu, 22 May 2025 16:38:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3O0pdcT50X2JtFUldvuuHQcfp3v/Gsxzw8U7YWSBo5w=; b=JifHOaNV8LD/NyZMqzFUdV1lfE f8mjhphMz2Trks0PJV6ckYq8vlyvEmQFK1pRgJAbvfIon2cgGJVvaCVCG1lG4pgCvNO77Md3POOPo r5gX7icXhYpTog0tMjPoSSfWLaDqLWnoEfhk/MDsc8Du7WibpFtl5RBbUAR4RJlDMGyc60TrMFDNJ BmVYq0fw1bMj4fYiP3R+jhBuCEiv9l6Nu5P62dRn9QWDnHfH6EDDK1vLlOLH5OzoROyqC31BlK9Z4 Rnj0vg+tm8+sqkdy+1yc72iU+kybigUWa19S2DoPdAq3EHiIJBwHmCaVVa3RLk3UynHj6N5lnjDsR p79+qbRQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uI8w3-00000001c3H-189S; Thu, 22 May 2025 16:38:23 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uHqKY-0000000Go0x-1iZ7 for linux-nvme@lists.infradead.org; Wed, 21 May 2025 20:46:27 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 70FE04A6DB; Wed, 21 May 2025 20:46:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 322E2C4CEEA; Wed, 21 May 2025 20:46:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747860385; bh=l0FQvf1M3ScltpOkIqN+MDVq9vIgvD938vpt9yDUCJ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vBKLuJ7sKUSpfyXuxBqq39G79W7Rz+UgR7DuXV2nFijDXVirka3E+lf3mI6fXB0Yo mZOUQfG73t+Xuth33SjGVYKaekrLaoII2/T3K6AZjNEhr0CPUF8ElsWBpwwwveUigJ ggl0EEtsqlQRlArrV8y7Eilmbkxj8H7zTcXtCzT9hboQyrqMZpNFXmf8Rn/4VDah9J TPGWWMi38PnhlLxhpPZ3PHppOIRAeJ2aNCzY68IyOav836l3I6flsMl32tjnY/gMza WxFzQG4WJNLON5DDl6tmYOC3c4khu2AQm7il4HADgQwwQxxOQsHUTU5BUtanTzVtfR U34EqaLwCIOwg== From: Kees Cook To: Kuniyuki Iwashima Cc: Kees Cook , "Gustavo A . R . Silva" , Eric Dumazet , Jakub Kicinski , "David S. Miller" , Paolo Abeni , Simon Horman , Ido Schimmel , netdev@vger.kernel.org, Willem de Bruijn , "Martin K. Petersen" , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , Mike Christie , Max Gurtovoy , Maurizio Lombardi , Dmitry Bogdanov , Mingzhe Zou , Christophe Leroy , "Dr. David Alan Gilbert" , Andrew Lunn , Stanislav Fomichev , Cosmin Ratiu , Lei Yang , Samuel Mendoza-Jonas , Paul Fertser , Alexander Aring , Stefan Schmidt , Miquel Raynal , Hayes Wang , Douglas Anderson , Grant Grundler , Jay Vosburgh , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Jiri Pirko , Jason Wang , Vladimir Oltean , Florian Fainelli , Kory Maincent , Maxim Georgiev , Aleksander Jan Bajkowski , Philipp Hahn , Eric Biggers , Ard Biesheuvel , Al Viro , Ahmed Zaki , Alexander Lobakin , Xiao Liang , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-wpan@vger.kernel.org, linux-usb@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH net-next v2 7/8] rtnetlink: do_setlink: Use struct sockaddr_storage Date: Wed, 21 May 2025 13:46:15 -0700 Message-Id: <20250521204619.2301870-7-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250521204310.it.500-kees@kernel.org> References: <20250521204310.it.500-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2148; i=kees@kernel.org; h=from:subject; bh=l0FQvf1M3ScltpOkIqN+MDVq9vIgvD938vpt9yDUCJ4=; b=owGbwMvMwCVmps19z/KJym7G02pJDBl61tMbYmZ7vqv3y5thHs3r9nVXSVtZ7MEJ73YFLVVlf crw4fn/jlIWBjEuBlkxRZYgO/c4F4+37eHucxVh5rAygQxh4OIUgImYKjAyfDV1aEz44sad4qiz 39HRp5zLnFf5iffcMym3Px+wdE/gY/ineFOBL/PIyU28LFO3x+ZnOm9YpcfdFuQ7kyW368Lt3AU cAA== X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250521_134626_489618_35597F61 X-CRM114-Status: GOOD ( 14.38 ) X-Mailman-Approved-At: Thu, 22 May 2025 09:38:03 -0700 X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Instead of a heap allocating a variably sized struct sockaddr and lying about the type in the call to netif_set_mac_address(), use a stack allocated struct sockaddr_storage. This lets us drop the cast and avoid the allocation. Putting "ss" on the stack means it will get a reused stack slot since it is the same size (128B) as other existing single-scope stack variables, like the vfinfo array (128B), so no additional stack space is used by this function. Acked-by: Gustavo A. R. Silva Signed-off-by: Kees Cook --- Cc: Kuniyuki Iwashima Cc: Eric Dumazet Cc: Jakub Kicinski Cc: "David S. Miller" Cc: Paolo Abeni Cc: Simon Horman Cc: Ido Schimmel Cc: --- net/core/rtnetlink.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9743f1c2ae3c..f9a35bdc58ad 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3080,17 +3080,7 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev, } if (tb[IFLA_ADDRESS]) { - struct sockaddr *sa; - int len; - - len = sizeof(sa_family_t) + max_t(size_t, dev->addr_len, - sizeof(*sa)); - sa = kmalloc(len, GFP_KERNEL); - if (!sa) { - err = -ENOMEM; - goto errout; - } - sa->sa_family = dev->type; + struct sockaddr_storage ss = { }; netdev_unlock_ops(dev); @@ -3098,10 +3088,9 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev, down_write(&dev_addr_sem); netdev_lock_ops(dev); - memcpy(sa->sa_data, nla_data(tb[IFLA_ADDRESS]), - dev->addr_len); - err = netif_set_mac_address(dev, (struct sockaddr_storage *)sa, extack); - kfree(sa); + ss.ss_family = dev->type; + memcpy(ss.__data, nla_data(tb[IFLA_ADDRESS]), dev->addr_len); + err = netif_set_mac_address(dev, &ss, extack); if (err) { up_write(&dev_addr_sem); goto errout; -- 2.34.1