From mboxrd@z Thu Jan 1 00:00:00 1970 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 DF8EF25F78D; Tue, 11 Mar 2025 15:40:21 +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=1741707622; cv=none; b=I2El+a0D6qSK+aBeKeyCiYVTa4U/eKRbdnGU5v6VlM/E0U2tzhC0aZXNFCjl0hjUWdAcX9uoCJ+eteOQFoUGhtwNtavdDsVrZ9r54RxeBZVmK1/vN4VO8eVK2fACZQBYzJ7wFS0dW1c69TVShW9N76XFnEMrlp1jBqglFJbsO8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741707622; c=relaxed/simple; bh=nowvR8z9b2cFXPbv49uUcxPzoqj0rXJT+zUTelPvP4I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jI4mp0DSA5zmycXr4J7BLfrMoU9p+n+ON/dlW80/RFAuHRGRkI0qhBcV/a/4nhEGyQtIqsmyju7DZeJf+uTD+xugIG1I0mVMxomyLg3DjtP/Giwb7rhATpi6eB1FNuj5WTazWF4TzDHHXRUQmymr4e9tFd4+gEZedUBgj/H9qkY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IefOVrF5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="IefOVrF5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65656C4CEE9; Tue, 11 Mar 2025 15:40:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741707621; bh=nowvR8z9b2cFXPbv49uUcxPzoqj0rXJT+zUTelPvP4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IefOVrF548pGg6A8MzH8MBpWykVD1+Qz4rtlC54Zaw3L5iqtqPp5cwDF9WXesbo/y SthBgT7KG+VFP/j5bKL69CgclMNJmz+MINZdEeQGxxw+z87WnaHGWE4Z9aIUbtV1BP vx0Gq08CM/nq+63B2agzcJxjy2Wh+NXxuWQLVTzk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+91161fe81857b396c8a0@syzkaller.appspotmail.com, Oscar Maes , Jiri Pirko , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.10 420/462] vlan: enforce underlying device type Date: Tue, 11 Mar 2025 16:01:26 +0100 Message-ID: <20250311145814.927998772@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145758.343076290@linuxfoundation.org> References: <20250311145758.343076290@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oscar Maes [ Upstream commit b33a534610067ade2bdaf2052900aaad99701353 ] Currently, VLAN devices can be created on top of non-ethernet devices. Besides the fact that it doesn't make much sense, this also causes a bug which leaks the address of a kernel function to usermode. When creating a VLAN device, we initialize GARP (garp_init_applicant) and MRP (mrp_init_applicant) for the underlying device. As part of the initialization process, we add the multicast address of each applicant to the underlying device, by calling dev_mc_add. __dev_mc_add uses dev->addr_len to determine the length of the new multicast address. This causes an out-of-bounds read if dev->addr_len is greater than 6, since the multicast addresses provided by GARP and MRP are only 6 bytes long. This behaviour can be reproduced using the following commands: ip tunnel add gretest mode ip6gre local ::1 remote ::2 dev lo ip l set up dev gretest ip link add link gretest name vlantest type vlan id 100 Then, the following command will display the address of garp_pdu_rcv: ip maddr show | grep 01:80:c2:00:00:21 Fix the bug by enforcing the type of the underlying device during VLAN device initialization. Fixes: 22bedad3ce11 ("net: convert multicast list to list_head") Reported-by: syzbot+91161fe81857b396c8a0@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/000000000000ca9a81061a01ec20@google.com/ Signed-off-by: Oscar Maes Reviewed-by: Jiri Pirko Link: https://patch.msgid.link/20250303155619.8918-1-oscmaes92@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/8021q/vlan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 64a94c9812da1..b45b9c9b12684 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -128,7 +128,8 @@ int vlan_check_real_dev(struct net_device *real_dev, { const char *name = real_dev->name; - if (real_dev->features & NETIF_F_VLAN_CHALLENGED) { + if (real_dev->features & NETIF_F_VLAN_CHALLENGED || + real_dev->type != ARPHRD_ETHER) { pr_info("VLANs not supported on %s\n", name); NL_SET_ERR_MSG_MOD(extack, "VLANs not supported on device"); return -EOPNOTSUPP; -- 2.39.5