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 E385D611A for ; Mon, 28 Aug 2023 10:44:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 029E5C433C7; Mon, 28 Aug 2023 10:44:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693219454; bh=MFTT5R5u/rNisn1JPmJcJgnd+MRRIvk8KHHgsHAK5po=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EszN/Pc4ix1UCLUlTacOePyCHt9mbEif42/fwMdzZsvPTPk9MGZ79Dl+8bxsP79WG v4NA/DZ6eBYEOntcJBWo9L3niPWzJwBQHV/bg9RWBJRw3OtxXexQ7obZlwN0PMQtz2 BRuJksX0IJ0ylC65B3cu0kfAliljbzC4NFAnI9SA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com, Ido Schimmel , Jiri Pirko , Jakub Kicinski , Paolo Abeni , Sasha Levin Subject: [PATCH 5.15 41/89] rtnetlink: Reject negative ifindexes in RTM_NEWLINK Date: Mon, 28 Aug 2023 12:13:42 +0200 Message-ID: <20230828101151.564388223@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101150.163430842@linuxfoundation.org> References: <20230828101150.163430842@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ido Schimmel [ Upstream commit 30188bd7838c16a98a520db1fe9df01ffc6ed368 ] Negative ifindexes are illegal, but the kernel does not validate the ifindex in the ancillary header of RTM_NEWLINK messages, resulting in the kernel generating a warning [1] when such an ifindex is specified. Fix by rejecting negative ifindexes. [1] WARNING: CPU: 0 PID: 5031 at net/core/dev.c:9593 dev_index_reserve+0x1a2/0x1c0 net/core/dev.c:9593 [...] Call Trace: register_netdevice+0x69a/0x1490 net/core/dev.c:10081 br_dev_newlink+0x27/0x110 net/bridge/br_netlink.c:1552 rtnl_newlink_create net/core/rtnetlink.c:3471 [inline] __rtnl_newlink+0x115e/0x18c0 net/core/rtnetlink.c:3688 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3701 rtnetlink_rcv_msg+0x439/0xd30 net/core/rtnetlink.c:6427 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:728 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:751 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2538 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2592 __sys_sendmsg+0x117/0x1e0 net/socket.c:2621 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 38f7b870d4a6 ("[RTNETLINK]: Link creation API") Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: Jakub Kicinski Link: https://lore.kernel.org/r/20230823064348.2252280-1-idosch@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/core/rtnetlink.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 7c1a2fd7d9532..1b71e5c582bbc 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3318,6 +3318,9 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, if (ifm->ifi_index > 0) { link_specified = true; dev = __dev_get_by_index(net, ifm->ifi_index); + } else if (ifm->ifi_index < 0) { + NL_SET_ERR_MSG(extack, "ifindex can't be negative"); + return -EINVAL; } else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME]) { link_specified = true; dev = rtnl_dev_get(net, NULL, tb[IFLA_ALT_IFNAME], ifname); -- 2.40.1