From mboxrd@z Thu Jan 1 00:00:00 1970 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 5A480C43461 for ; Mon, 12 Apr 2021 16:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BC6361379 for ; Mon, 12 Apr 2021 16:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244781AbhDLQ2g (ORCPT ); Mon, 12 Apr 2021 12:28:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:57616 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243408AbhDLQ0M (ORCPT ); Mon, 12 Apr 2021 12:26:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AC00060200; Mon, 12 Apr 2021 16:24:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618244692; bh=iaPirG7GpMnweMUpMRsnT/uw9iCtZxePVwuIJKbij14=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QOf8ark0UDLPRRs0auVZgWB0mW/Q5VKJ1N9pWgi3qflluDxwHsYZuDL7nVKzcyM+c VT/Txc05OoFcwniEBRLLMs4rfmZGjcYh8Awzxx0ZBeOZxIr0Aa49GLEldXTegCIEo4 mfmH8ooMC4gmE2U1EExYKbkhCYmlmZGC0zJVlvLdGCr7L3BV9LK/f03xL1qLwVL6/P 14gqZZdkqILkd8J3DHZQIVrPAZ3piHkk6oEzwtJSnUWqUoleI/QR+2UoT5dAVMTbzp 90BrI2JHBt4+IjNrGh5AwNtjoCVV7BGiL3zgpqDfIvOrUGW+gQL59e65PEpOjMq2eY XEFxemzdjOEsQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Phillip Potter , syzbot+001516d86dbe88862cec@syzkaller.appspotmail.com, Eric Dumazet , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 40/46] net: tun: set tun->dev->addr_len during TUNSETLINK processing Date: Mon, 12 Apr 2021 12:23:55 -0400 Message-Id: <20210412162401.314035-40-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210412162401.314035-1-sashal@kernel.org> References: <20210412162401.314035-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Phillip Potter [ Upstream commit cca8ea3b05c972ffb5295367e6c544369b45fbdd ] When changing type with TUNSETLINK ioctl command, set tun->dev->addr_len to match the appropriate type, using new tun_get_addr_len utility function which returns appropriate address length for given type. Fixes a KMSAN-found uninit-value bug reported by syzbot at: https://syzkaller.appspot.com/bug?id=0766d38c656abeace60621896d705743aeefed51 Reported-by: syzbot+001516d86dbe88862cec@syzkaller.appspotmail.com Diagnosed-by: Eric Dumazet Signed-off-by: Phillip Potter Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/tun.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index accde25a66a0..c671d8e25774 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -69,6 +69,14 @@ #include #include #include +#include +#include +#include +#include +#include +#include +#include +#include #include #include @@ -2978,6 +2986,45 @@ static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog __rcu **prog_p, return __tun_set_ebpf(tun, prog_p, prog); } +/* Return correct value for tun->dev->addr_len based on tun->dev->type. */ +static unsigned char tun_get_addr_len(unsigned short type) +{ + switch (type) { + case ARPHRD_IP6GRE: + case ARPHRD_TUNNEL6: + return sizeof(struct in6_addr); + case ARPHRD_IPGRE: + case ARPHRD_TUNNEL: + case ARPHRD_SIT: + return 4; + case ARPHRD_ETHER: + return ETH_ALEN; + case ARPHRD_IEEE802154: + case ARPHRD_IEEE802154_MONITOR: + return IEEE802154_EXTENDED_ADDR_LEN; + case ARPHRD_PHONET_PIPE: + case ARPHRD_PPP: + case ARPHRD_NONE: + return 0; + case ARPHRD_6LOWPAN: + return EUI64_ADDR_LEN; + case ARPHRD_FDDI: + return FDDI_K_ALEN; + case ARPHRD_HIPPI: + return HIPPI_ALEN; + case ARPHRD_IEEE802: + return FC_ALEN; + case ARPHRD_ROSE: + return ROSE_ADDR_LEN; + case ARPHRD_NETROM: + return AX25_ADDR_LEN; + case ARPHRD_LOCALTLK: + return LTALK_ALEN; + default: + return 0; + } +} + static long __tun_chr_ioctl(struct file *file, unsigned int cmd, unsigned long arg, int ifreq_len) { @@ -3133,6 +3180,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, ret = -EBUSY; } else { tun->dev->type = (int) arg; + tun->dev->addr_len = tun_get_addr_len(tun->dev->type); netif_info(tun, drv, tun->dev, "linktype set to %d\n", tun->dev->type); ret = 0; -- 2.30.2