From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 AFF213C1D6D; Thu, 30 Jul 2026 14:25:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785421531; cv=none; b=NE7FAUg9FdNW3fUPWzib4R5+QLr/DeQFJNfhmCFHoFslCh5GkKw0mVvANJtD7X8tYupOoTINjfrPUCGHr3B1XVUMR0e1wLUT5T1lFlVheS1QNLvpTABXtH2yFwr57UX6sEblbioBUrGtYHJ4u35BxhMsZNd30EJVTFj/2itNpKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785421531; c=relaxed/simple; bh=KbQlvpfOVN/CtdvfboPtfMwO0MIvPZepgXt09vQ8bNM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qSDK9qLYHghSJ88jnIvAKzDrEk68G5TsZ54eqqBMzeppULIPtJUAkoeUmWqFK38B8NrR7z6O/qHoM8cyO+xI0BoIi1pGLDJ0J7/YV90mMq54wTN8UfTVviy4NpEJsffJDv6Gt117Z81Tq1bQm4Uer5SboSO2DAWACxHm7AaDFmU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qc5WA/VV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qc5WA/VV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 113DC1F000E9; Thu, 30 Jul 2026 14:25:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785421530; bh=EE+ErqsjZJdg+Hq9WTE13aTpFWz2w3bMTTtiOt1ql08=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=qc5WA/VVHXJdZr8eEdSgLsneyeiB3XZGAu9vkoZAaD8L4mk+JxoWFXE1FfjmZMCYi KzIXmCB1pFfj2L/oRUhzNHOblEKfUd53YBAN1oeYBdMPdMf849t4bbvglLOEzIRgJm qmsLbc1cetg8Tv7HXB8606+XCl8Xjf4ph4ZO99D4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiang Mei , Weiming Shi , David Ahern , Paolo Abeni , Sasha Levin Subject: [PATCH 7.1 136/744] mpls: fix NULL deref in mpls_valid_fib_dump_req() on CONFIG_INET=n Date: Thu, 30 Jul 2026 16:06:49 +0200 Message-ID: <20260730141447.170507676@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141444.267951807@linuxfoundation.org> References: <20260730141444.267951807@linuxfoundation.org> User-Agent: quilt/0.69 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 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weiming Shi [ Upstream commit 56d96fededd61192cd7cc8d2b0f36adfd59036c3 ] On CONFIG_INET=n builds, mpls_valid_fib_dump_req() walks the parsed attribute table itself instead of calling ip_valid_fib_dump_req(). The RTA_OIF arm passes tb[RTA_OIF] to nla_get_u32() without checking it is present, so an RTM_GETROUTE dump for AF_MPLS with strict checking and no RTA_OIF hits a NULL dereference. RTM_GETROUTE is RTNL_KIND_GET, which rtnetlink_rcv_msg() permits without CAP_NET_ADMIN, so an unprivileged user can trigger it. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:mpls_valid_fib_dump_req (net/mpls/af_mpls.c:2189) Call Trace: mpls_dump_routes (net/mpls/af_mpls.c:2236) netlink_dump (net/netlink/af_netlink.c:2331) __netlink_dump_start (net/netlink/af_netlink.c:2446) rtnetlink_rcv_msg (net/core/rtnetlink.c:7033) netlink_rcv_skb (net/netlink/af_netlink.c:2556) netlink_unicast (net/netlink/af_netlink.c:1345) netlink_sendmsg (net/netlink/af_netlink.c:1900) __sock_sendmsg (net/socket.c:790) ____sys_sendmsg (net/socket.c:2684) ___sys_sendmsg (net/socket.c:2738) __sys_sendmsg (net/socket.c:2770) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Skip unset attributes, as ip_valid_fib_dump_req() does. Fixes: 196cfebf8972 ("net/mpls: Handle kernel side filtering of route dumps") Assisted-by: Claude:claude-opus-4-8 Reported-by: Xiang Mei Signed-off-by: Weiming Shi Reviewed-by: David Ahern Link: https://patch.msgid.link/20260711114958.1009619-3-bestswngs@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/mpls/af_mpls.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 26340a7306b591..b64a8b1bac0961 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -2186,6 +2186,9 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, int ifindex; if (i == RTA_OIF) { + if (!tb[i]) + continue; + ifindex = nla_get_u32(tb[i]); filter->dev = dev_get_by_index_rcu(net, ifindex); if (!filter->dev) -- 2.53.0