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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97642C433F5 for ; Mon, 25 Oct 2021 19:43:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EF3B6112F for ; Mon, 25 Oct 2021 19:43:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237207AbhJYTph (ORCPT ); Mon, 25 Oct 2021 15:45:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:59360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237402AbhJYTng (ORCPT ); Mon, 25 Oct 2021 15:43:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 92B236112F; Mon, 25 Oct 2021 19:37:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635190666; bh=4qRojGq1/efZNWYMCbmU9TRiIk0DdEoCaOqKrf8hOkQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1Kjp7Gm1P7ZTZwatVCQ0goxCv3a7nxTpnaG+6YnwrGDcmdQrMGHVnyTBOZlRowQQo NXQKWNWsPMDi323iIEgHsN2ukAgl3l3utBCcxqqy+5hPHpH1ttlIiDv+RKh5q0avWC cTaU75ht9+0SeEAITvmyx2BmmJa4Z13ni222st48= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Juhee Kang , Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 5.14 024/169] netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value Date: Mon, 25 Oct 2021 21:13:25 +0200 Message-Id: <20211025191020.849184458@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211025191017.756020307@linuxfoundation.org> References: <20211025191017.756020307@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Juhee Kang [ Upstream commit 902c0b1887522a099aa4e1e6b4b476c2fe5dd13e ] Currently, when the rule related to IDLETIMER is added, idletimer_tg timer structure is initialized by kmalloc on executing idletimer_tg_create function. However, in this process timer->timer_type is not defined to a specific value. Thus, timer->timer_type has garbage value and it occurs kernel panic. So, this commit fixes the panic by initializing timer->timer_type using kzalloc instead of kmalloc. Test commands: # iptables -A OUTPUT -j IDLETIMER --timeout 1 --label test $ cat /sys/class/xt_idletimer/timers/test Killed Splat looks like: BUG: KASAN: user-memory-access in alarm_expires_remaining+0x49/0x70 Read of size 8 at addr 0000002e8c7bc4c8 by task cat/917 CPU: 12 PID: 917 Comm: cat Not tainted 5.14.0+ #3 79940a339f71eb14fc81aee1757a20d5bf13eb0e Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: dump_stack_lvl+0x6e/0x9c kasan_report.cold+0x112/0x117 ? alarm_expires_remaining+0x49/0x70 __asan_load8+0x86/0xb0 alarm_expires_remaining+0x49/0x70 idletimer_tg_show+0xe5/0x19b [xt_IDLETIMER 11219304af9316a21bee5ba9d58f76a6b9bccc6d] dev_attr_show+0x3c/0x60 sysfs_kf_seq_show+0x11d/0x1f0 ? device_remove_bin_file+0x20/0x20 kernfs_seq_show+0xa4/0xb0 seq_read_iter+0x29c/0x750 kernfs_fop_read_iter+0x25a/0x2c0 ? __fsnotify_parent+0x3d1/0x570 ? iov_iter_init+0x70/0x90 new_sync_read+0x2a7/0x3d0 ? __x64_sys_llseek+0x230/0x230 ? rw_verify_area+0x81/0x150 vfs_read+0x17b/0x240 ksys_read+0xd9/0x180 ? vfs_write+0x460/0x460 ? do_syscall_64+0x16/0xc0 ? lockdep_hardirqs_on+0x79/0x120 __x64_sys_read+0x43/0x50 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f0cdc819142 Code: c0 e9 c2 fe ff ff 50 48 8d 3d 3a ca 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 RSP: 002b:00007fff28eee5b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f0cdc819142 RDX: 0000000000020000 RSI: 00007f0cdc032000 RDI: 0000000000000003 RBP: 00007f0cdc032000 R08: 00007f0cdc031010 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 00005607e9ee31f0 R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 Fixes: 68983a354a65 ("netfilter: xtables: Add snapshot of hardidletimer target") Signed-off-by: Juhee Kang Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/xt_IDLETIMER.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c index 7b2f359bfce4..2f7cf5ecebf4 100644 --- a/net/netfilter/xt_IDLETIMER.c +++ b/net/netfilter/xt_IDLETIMER.c @@ -137,7 +137,7 @@ static int idletimer_tg_create(struct idletimer_tg_info *info) { int ret; - info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL); + info->timer = kzalloc(sizeof(*info->timer), GFP_KERNEL); if (!info->timer) { ret = -ENOMEM; goto out; -- 2.33.0