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 59F3122D799; Mon, 10 Mar 2025 17:26:59 +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=1741627619; cv=none; b=TXxei7BAzB1LE6vKPfhP6VS3S45ug3OMFmPduegaSLq9LOLNYtS6W5s58OSalwJhSd1hSXKB6GqEbxyL/FcFI/wtHwlwk/LgVNOkVsF0EcCgmhee+Ll6eeGXeVIyVoESMel7WJFp8RfkfcSS0KaNnwJm2QBVQajwMLKGnqCUnlA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741627619; c=relaxed/simple; bh=BE0eYc9MxovCFBI7bv/GJ7UfnCTsDtfgZTWujyHdk/Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BKEAaL/JdxTXnCdpkaCjObKJCluY4a9jxt093nN8tuDN4+i6xzjS1C8mDB/wLgm6/OloKl0DEW0WHKUBowjdcKMgeQA19MCJWR3P0a/D8NpXUt8MgOT5tFz8lylsX9kWlstFwDpE0Y2kocOudVvvSlYcNh0ucRNuJ7A6xA14LUE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=m5uuLmB7; 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="m5uuLmB7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8803C4CEE5; Mon, 10 Mar 2025 17:26:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741627619; bh=BE0eYc9MxovCFBI7bv/GJ7UfnCTsDtfgZTWujyHdk/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m5uuLmB7KlW3XAr0VhEX3tlAH8wXjc+nDiSnuFwDl98eb/JdznnGRh++ORT+PpOSg ycyx8tvyBUD3Y0g2apq3Or8FEOaDAA7Fj+1w1YvKXhMYAgrzv5bh5ozIV/UNQ9mL/c EwS5aOfLAw81M0yNdoLMZXynk52cIQTL5oUPXmYk= 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 6.12 192/269] vlan: enforce underlying device type Date: Mon, 10 Mar 2025 18:05:45 +0100 Message-ID: <20250310170505.355930921@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170457.700086763@linuxfoundation.org> References: <20250310170457.700086763@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 6.12-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 e45187b882206..41be38264493d 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