From patchwork Mon Nov 4 22:25:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 13862173 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B0F021C32E2; Mon, 4 Nov 2024 22:25:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730759116; cv=none; b=fB0G+B/UHcuozlA0VdBmVk8uYjjOw9itQyU8SfPSZuNaX4+UiVC1cdEjrfZmQTEwxh7OJ2N0PWKF+P89Qsx82ozmH9MOij51lFG3gfzXaGf5SW007J0H1UJSxsfXkCny0dV9F6k4HzAEvfdYjCFEPiV4Hh85D8zVcE7diJznQwc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730759116; c=relaxed/simple; bh=nnathdskUxGu/VhOcY1X1w1dugmZGedEo3+8ThGIWak=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=FVm+XKmadRQe8L9YVo9nUdNVH7RhzZ9FsgWt1URPgRgxKHjXXir8vAOB31Bvi2sPff+utQXUxDmOKaPLNoLKw5gc2JAaYcX5CtX+XCHsRFbqmf7RoYYXjbJCSXdog8S/O0gEQzoVeyFQPM9hQQkwMW5/NXbkawsllQ8DibEoQZ8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F6iEvdNX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="F6iEvdNX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8160EC4CED0; Mon, 4 Nov 2024 22:25:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730759116; bh=nnathdskUxGu/VhOcY1X1w1dugmZGedEo3+8ThGIWak=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F6iEvdNXK1P9b+EeoDpbBDRPc5nyEPF25BUX2NtZe+r1mN4d1dKP997O5Wu39g2nW SJVR8Hbc3B40s9MzXVCDy0NlbgaLBFE5fIboQOsATCBlRzRkB0sa3sqNt2eINQlqSZ iO6e5f4PsGSNUgMpS53nrsiZZKkgvvJbcHfBfgxI2x65pL8rchlm0SYBDYvZqQnNd4 TJbT9/7+4dhk8KOSa1xO1FrnQZLEU433bwhPwwwqKj7Z1F+iI2HcAsv2B0i0Ix1/3M j4domQUn4WsCn8rNXdP87d/JM9oMq2d7AMztS+NriQ5F2Hf7rLvtyeDfz6nR5RLWw1 xirX9VQ5tdQ1A== From: Kees Cook To: Jakub Kicinski Cc: Kees Cook , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH RFC 2/5] net: core: dev.c confirmed to use classic sockaddr Date: Mon, 4 Nov 2024 14:25:04 -0800 Message-Id: <20241104222513.3469025-2-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241104221450.work.053-kees@kernel.org> References: <20241104221450.work.053-kees@kernel.org> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1411; i=kees@kernel.org; h=from:subject; bh=nnathdskUxGu/VhOcY1X1w1dugmZGedEo3+8ThGIWak=; b=owGbwMvMwCVmps19z/KJym7G02pJDOmangcXe0/zuTZ9zjqzEOlFk17VPHGVKPP7/FnKSNH9n Nd0jr2NHaUsDGJcDLJiiixBdu5xLh5v28Pd5yrCzGFlAhnCwMUpABPJf8bIsFto5mf+rK9ehbds Dn/0cdfbtURj05z80LDIKaYfCyou5jAy3Jq4QGP9t/1MRtNsNzncdflxWXFazmadFsaeB5f/Gqh 1MgIA X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Add comments about the sockaddr arguments being actual classic "max 14 bytes in sa_data" sockaddr. Signed-off-by: Kees Cook --- net/core/dev.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index 582466a0176a..c95779cb42a6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9075,7 +9075,8 @@ EXPORT_SYMBOL(dev_pre_changeaddr_notify); /** * dev_set_mac_address - Change Media Access Control Address * @dev: device - * @sa: new address + * @sa: new address in a classic "struct sockaddr", which will never + * have more than 14 bytes in @sa::sa_data * @extack: netlink extended ack * * Change the hardware (MAC) address of the device @@ -9109,6 +9110,7 @@ EXPORT_SYMBOL(dev_set_mac_address); DECLARE_RWSEM(dev_addr_sem); +/* "sa" is a classic sockaddr: it will only ever use 14 bytes from sa_data. */ int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa, struct netlink_ext_ack *extack) { @@ -9121,6 +9123,7 @@ int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa, } EXPORT_SYMBOL(dev_set_mac_address_user); +/* "sa" is a classic sockaddr: it will only ever use 14 bytes from sa_data. */ int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name) { size_t size = sizeof(sa->sa_data);