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 E3C5022D4F4; Mon, 10 Mar 2025 17:34:43 +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=1741628084; cv=none; b=UaVqi/9o33QuAWu9etM77JQrE21wk+4KIrJnj2F8hbv6RYBbCmo60fnbNNKFdgwgVssIFGNvOpTpPvMAJTA9kTZrWF3siAA89i7T88vPepU6jEaKUfNmQe2zmrAKmJPrhAd0wz8cn81u69gd5j9vFawIOndxtcmuw88MoFQlUrE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741628084; c=relaxed/simple; bh=GKZH3yuEhZ6dq7r+J5VRdKaZERbV4DqnQz1Wgmt+0IE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ssls/kQYS16YV9oOmDWZgx4QJpTNsZDHXuGNFAPXKqnVi2JRJtlp7+bjwbpEoZy30CTpR61q/zX4pSoiPpVz7ahJQv7Aj0ZLxOdfWtYpTpzSvLNQtTtUh10iQ0ASjVpTgjm0LEvPHz1wFGAWcuq3N8r4z9xOC83sXhlbio5QeLs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GKpESJfk; 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="GKpESJfk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D8EAC4CEE5; Mon, 10 Mar 2025 17:34:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741628083; bh=GKZH3yuEhZ6dq7r+J5VRdKaZERbV4DqnQz1Wgmt+0IE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GKpESJfk+fxa1OMhkfN+8+vuqwF5o/K5LUldtkP51mKEZNgwRd8EVNm2uCRw2vwKS M8DNEZT1B+3Iit8A0lIk3LcR+VklOkqk+m49XE6hNqVF+YBRtE18V1X7VvahVScIRE br5sTI0Hrr0voWxZTvw/bGJdKn68P8Cyqjrj5URY= 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 6.6 082/145] vlan: enforce underlying device type Date: Mon, 10 Mar 2025 18:06:16 +0100 Message-ID: <20250310170438.068895260@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170434.733307314@linuxfoundation.org> References: <20250310170434.733307314@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 6.6-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 e40aa3e3641cb..b477ba37a6991 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -131,7 +131,8 @@ 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