From patchwork Thu Mar 19 13:04:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229027 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B34AC4332D for ; Thu, 19 Mar 2020 13:28:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1FFB2080C for ; Thu, 19 Mar 2020 13:28:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624519; bh=jJkSqg+i9P7iPzHlRnCaYYKLwrXSs46x9cFnO80Ekvk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qLer4JNkGN8j9aJIrRWwzq3Q/NK5BAMvYefIrw3T0OrI//ZFrPns3KaaMTWWxxhGv 0fTbcEHtc3UBqZQxmJGJG6eRNdSNEBRM9VmGt/gNQwJAFt42NvcIF+hD8Hyt8I6rXL zYPPm58bo3yJI0QC+b9l3yUcex+PTd8198H33PzY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730469AbgCSN0h (ORCPT ); Thu, 19 Mar 2020 09:26:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:54636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730795AbgCSN0g (ORCPT ); Thu, 19 Mar 2020 09:26:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5101E20658; Thu, 19 Mar 2020 13:26:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624395; bh=jJkSqg+i9P7iPzHlRnCaYYKLwrXSs46x9cFnO80Ekvk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WHLc4gijUgZuClmceHp+cWKVgrdM0DwVHX6W7xMFksIOzpeQevCkIsOGzNWa6AcRM O+4s069WcFnHhlCm86dTwCnFe5HfXi9iewGVaPjhM9rJsZy2sayAGo1TUegBWOvvG7 yneji/Ltop9DwD91CrLYjJYSNjhCd/uICSmoPSf4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Taehee Yoo , "David S. Miller" , Sasha Levin Subject: [PATCH 5.5 47/65] net: rmnet: fix NULL pointer dereference in rmnet_changelink() Date: Thu, 19 Mar 2020 14:04:29 +0100 Message-Id: <20200319123941.236811843@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123926.466988514@linuxfoundation.org> References: <20200319123926.466988514@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Taehee Yoo [ Upstream commit 1eb1f43a6e37282348a41e3d68f5e9a6a4359212 ] In the rmnet_changelink(), it uses IFLA_LINK without checking NULL pointer. tb[IFLA_LINK] could be NULL pointer. So, NULL-ptr-deref could occur. rmnet already has a lower interface (real_dev). So, after this patch, rmnet_changelink() does not use IFLA_LINK anymore. Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet0 link dummy0 type rmnet mux_id 1 ip link set rmnet0 type rmnet mux_id 2 Splat looks like: [ 90.578726][ T1131] general protection fault, probably for non-canonical address 0xdffffc0000000000I [ 90.581121][ T1131] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 90.582380][ T1131] CPU: 2 PID: 1131 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 90.584285][ T1131] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 90.587506][ T1131] RIP: 0010:rmnet_changelink+0x5a/0x8a0 [rmnet] [ 90.588546][ T1131] Code: 83 ec 20 48 c1 ea 03 80 3c 02 00 0f 85 6f 07 00 00 48 8b 5e 28 48 b8 00 00 00 00 00 0 [ 90.591447][ T1131] RSP: 0018:ffff8880ce78f1b8 EFLAGS: 00010247 [ 90.592329][ T1131] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8880ce78f8b0 [ 90.593253][ T1131] RDX: 0000000000000000 RSI: ffff8880ce78f4a0 RDI: 0000000000000004 [ 90.594058][ T1131] RBP: ffff8880cf543e00 R08: 0000000000000002 R09: 0000000000000002 [ 90.594859][ T1131] R10: ffffffffc0586a40 R11: 0000000000000000 R12: ffff8880ca47c000 [ 90.595690][ T1131] R13: ffff8880ca47c000 R14: ffff8880cf545000 R15: 0000000000000000 [ 90.596553][ T1131] FS: 00007f21f6c7e0c0(0000) GS:ffff8880da400000(0000) knlGS:0000000000000000 [ 90.597504][ T1131] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 90.599418][ T1131] CR2: 0000556e413db458 CR3: 00000000c917a002 CR4: 00000000000606e0 [ 90.600289][ T1131] Call Trace: [ 90.600631][ T1131] __rtnl_newlink+0x922/0x1270 [ 90.601194][ T1131] ? lock_downgrade+0x6e0/0x6e0 [ 90.601724][ T1131] ? rtnl_link_unregister+0x220/0x220 [ 90.602309][ T1131] ? lock_acquire+0x164/0x3b0 [ 90.602784][ T1131] ? is_bpf_image_address+0xff/0x1d0 [ 90.603331][ T1131] ? rtnl_newlink+0x4c/0x90 [ 90.603810][ T1131] ? kernel_text_address+0x111/0x140 [ 90.604419][ T1131] ? __kernel_text_address+0xe/0x30 [ 90.604981][ T1131] ? unwind_get_return_address+0x5f/0xa0 [ 90.605616][ T1131] ? create_prof_cpu_mask+0x20/0x20 [ 90.606304][ T1131] ? arch_stack_walk+0x83/0xb0 [ 90.606985][ T1131] ? stack_trace_save+0x82/0xb0 [ 90.607656][ T1131] ? stack_trace_consume_entry+0x160/0x160 [ 90.608503][ T1131] ? deactivate_slab.isra.78+0x2c5/0x800 [ 90.609336][ T1131] ? kasan_unpoison_shadow+0x30/0x40 [ 90.610096][ T1131] ? kmem_cache_alloc_trace+0x135/0x350 [ 90.610889][ T1131] ? rtnl_newlink+0x4c/0x90 [ 90.611512][ T1131] rtnl_newlink+0x65/0x90 [ ... ] Fixes: 23790ef12082 ("net: qualcomm: rmnet: Allow to configure flags for existing devices") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c index 471e3b2a1403a..ac58f584190bd 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c @@ -300,10 +300,8 @@ static int rmnet_changelink(struct net_device *dev, struct nlattr *tb[], if (!dev) return -ENODEV; - real_dev = __dev_get_by_index(dev_net(dev), - nla_get_u32(tb[IFLA_LINK])); - - if (!real_dev || !rmnet_is_real_dev_registered(real_dev)) + real_dev = priv->real_dev; + if (!rmnet_is_real_dev_registered(real_dev)) return -ENODEV; port = rmnet_get_port_rtnl(real_dev);