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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 25CC9C433E2 for ; Tue, 9 Jun 2020 00:10:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E6A5F2072F for ; Tue, 9 Jun 2020 00:10:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591661425; bh=ELK744J/8qKjfSZZ7rJvMXPHFOvT+Jq9rLbg63EOrh0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZCMev6Wb6mwA6OiofrOC2TCHB5Ff2Vbbx/Z+Utjf9aS3D7+fGcgYQF+5ptdj8kaGw 5JmD0PIs+IeFeOhYZd8amxxk8pxqPbcnhNJ3cypuJH6mXOm9kmD44IHMvAm6MBkkCi NMSMRMxa2rq7lAo7mDrQLwRDX6grLjNMJIxBBGPM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730929AbgFHXUQ (ORCPT ); Mon, 8 Jun 2020 19:20:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:37758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730212AbgFHXQZ (ORCPT ); Mon, 8 Jun 2020 19:16:25 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D2ED220774; Mon, 8 Jun 2020 23:16:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658184; bh=ELK744J/8qKjfSZZ7rJvMXPHFOvT+Jq9rLbg63EOrh0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WuulyLi5frMwDGoh7bhnwR86621qQ28qkW4juvOnp6BRKDL1NtLvorC5Tg/Ce85fX z2HiCkMdoDrNMttTkkvAreN++YJ3hkzRxQjW105csj4qtHulelp4Oc5TM5/RfF2Bty 5FhDjo5tKLpFdIoS0y02c8VrZXXlB0uQ6Agf/KMI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , syzbot , "David S . Miller" , Greg Kroah-Hartman , linux-hams@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 207/606] ax25: fix setsockopt(SO_BINDTODEVICE) Date: Mon, 8 Jun 2020 19:05:32 -0400 Message-Id: <20200608231211.3363633-207-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608231211.3363633-1-sashal@kernel.org> References: <20200608231211.3363633-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit 687775cec056b38a4c8f3291e0dd7a9145f7b667 ] syzbot was able to trigger this trace [1], probably by using a zero optlen. While we are at it, cap optlen to IFNAMSIZ - 1 instead of IFNAMSIZ. [1] BUG: KMSAN: uninit-value in strnlen+0xf9/0x170 lib/string.c:569 CPU: 0 PID: 8807 Comm: syz-executor483 Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 strnlen+0xf9/0x170 lib/string.c:569 dev_name_hash net/core/dev.c:207 [inline] netdev_name_node_lookup net/core/dev.c:277 [inline] __dev_get_by_name+0x75/0x2b0 net/core/dev.c:778 ax25_setsockopt+0xfa3/0x1170 net/ax25/af_ax25.c:654 __compat_sys_setsockopt+0x4ed/0x910 net/compat.c:403 __do_compat_sys_setsockopt net/compat.c:413 [inline] __se_compat_sys_setsockopt+0xdd/0x100 net/compat.c:410 __ia32_compat_sys_setsockopt+0x62/0x80 net/compat.c:410 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f57dd9 Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000ffae8c1c EFLAGS: 00000217 ORIG_RAX: 000000000000016e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000101 RDX: 0000000000000019 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Local variable ----devname@ax25_setsockopt created at: ax25_setsockopt+0xe6/0x1170 net/ax25/af_ax25.c:536 ax25_setsockopt+0xe6/0x1170 net/ax25/af_ax25.c:536 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ax25/af_ax25.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index ff57ea89c27e..fd91cd34f25e 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -635,8 +635,10 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname, break; case SO_BINDTODEVICE: - if (optlen > IFNAMSIZ) - optlen = IFNAMSIZ; + if (optlen > IFNAMSIZ - 1) + optlen = IFNAMSIZ - 1; + + memset(devname, 0, sizeof(devname)); if (copy_from_user(devname, optval, optlen)) { res = -EFAULT; -- 2.25.1