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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_2 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 DCDA1C433F5 for ; Thu, 23 Sep 2021 11:22:26 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A506660EC0 for ; Thu, 23 Sep 2021 11:22:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A506660EC0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:CC:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=dHLawDzZR4LPRth4KPgAGfIQL2k81EM32LZRdlG2Ofw=; b=AxF5uGBHFgvzsT 0rzeD0Tn2RGSn1XkYuBxB2EEvC39q6RATc3EbMyb5tAQsA6qmJlFHve4n0YQmw6kGV68xHi7xwyFl s5bG7God/Yq7HOdve/bFBcpdIT04sCwTiylvVVWQx+gWU3JlFWmKr7/zLGucN/DeVrK3CyNXQePCG uGUwEekAFcRihCo9nID3XjFeyF6s/jvtJTSV+aZSmCcDXi7GCC/EmXBmoI6VC5/+uuif64LGrxzBI gikvSgcs5LPDBwyQmZK6HYrcAa9eb6jBPmK+Hl7hJMzwLKAEFnJoA/xphsU3HsTqtVaiyoNVOXJcP FSb7B87MxeGYlxhxcAcw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTMld-00B4GQ-MI; Thu, 23 Sep 2021 11:19:53 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTMlZ-00B4Fy-7Q; Thu, 23 Sep 2021 11:19:50 +0000 X-UUID: 6c90333d6dfa46a4830d6a1a9d3eb111-20210923 X-UUID: 6c90333d6dfa46a4830d6a1a9d3eb111-20210923 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1490345102; Thu, 23 Sep 2021 04:19:43 -0700 Received: from mtkexhb02.mediatek.inc (172.21.101.103) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 23 Sep 2021 04:19:41 -0700 Received: from MTKCAS06.mediatek.inc (172.21.101.30) by mtkexhb02.mediatek.inc (172.21.101.103) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 23 Sep 2021 19:19:28 +0800 Received: from mtksdccf07 (172.21.84.99) by MTKCAS06.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 23 Sep 2021 19:19:22 +0800 Message-ID: <5f7a9ed1dabba25596c38a8e7c32ee5750b80459.camel@mediatek.com> Subject: Re: [PATCH] scs: Release kasan vmalloc poison in scs_free process From: Kuan-Ying Lee To: , CC: , , "Matthias Brugger" , Will Deacon , "Sami Tolvanen" , "moderated list:ARM/Mediatek SoC support" , "moderated list:ARM/Mediatek SoC support" Date: Thu, 23 Sep 2021 19:19:21 +0800 In-Reply-To: <20210923095316.13867-1-yee.lee@mediatek.com> References: <20210923095316.13867-1-yee.lee@mediatek.com> X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210923_041949_330060_C3889967 X-CRM114-Status: GOOD ( 19.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 2021-09-23 at 17:53 +0800, yee.lee@mediatek.com wrote: > From: Yee Lee > > Since scs allocation has been moved to vmalloc region, the > shadow stack is protected by kasan_posion_vmalloc. > However, the vfree_atomic operation needs to access > its context for scs_free process and causes kasan error > as the dump info below. > > This patch Adds kasan_unpoison_vmalloc() before vfree_atomic, > which aligns to the prior flow as using kmem_cache. > The vmalloc region will go back posioned in the following > vumap() operations. > > ================================================================== > BUG: KASAN: vmalloc-out-of-bounds in llist_add_batch+0x60/0xd4 > Write of size 8 at addr ffff8000100b9000 by task kthreadd/2 > > CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.15.0-rc2-11681-(skip) > Hardware name: linux,dummy-virt (DT) > Call trace: > dump_backtrace+0x0/0x43c > show_stack+0x1c/0x2c > dump_stack_lvl+0x68/0x84 > print_address_description+0x80/0x394 > kasan_report+0x180/0x1dc > __asan_report_store8_noabort+0x48/0x58 > llist_add_batch+0x60/0xd4 > vfree_atomic+0x60/0xe0 > scs_free+0x1dc/0x1fc > scs_release+0xa4/0xd4 > free_task+0x30/0xe4 > __put_task_struct+0x1ec/0x2e0 > delayed_put_task_struct+0x5c/0xa0 > rcu_do_batch+0x62c/0x8a0 > rcu_core+0x60c/0xc14 > rcu_core_si+0x14/0x24 > __do_softirq+0x19c/0x68c > irq_exit+0x118/0x2dc > handle_domain_irq+0xcc/0x134 > gic_handle_irq+0x7c/0x1bc > call_on_irq_stack+0x40/0x70 > do_interrupt_handler+0x78/0x9c > el1_interrupt+0x34/0x60 > el1h_64_irq_handler+0x1c/0x2c > el1h_64_irq+0x78/0x7c > _raw_spin_unlock_irqrestore+0x40/0xcc > sched_fork+0x4f0/0xb00 > copy_process+0xacc/0x3648 > kernel_clone+0x168/0x534 > kernel_thread+0x13c/0x1b0 > kthreadd+0x2bc/0x400 > ret_from_fork+0x10/0x20 > > Memory state around the buggy address: > ffff8000100b8f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 > ffff8000100b8f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 > >ffff8000100b9000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 > ^ > ffff8000100b9080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 > ffff8000100b9100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 > ================================================================== > > CC: Matthias Brugger > CC: Will Deacon > CC: Sami Tolvanen > Signed-off-by: Yee Lee > --- > kernel/scs.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/scs.c b/kernel/scs.c > index e2a71fc82fa0..25c0d8e416e6 100644 > --- a/kernel/scs.c > +++ b/kernel/scs.c > @@ -68,6 +68,7 @@ void scs_free(void *s) > > __scs_account(s, -1); > > + kasan_unpoison_vmalloc(s, SCS_SIZE); > /* > * We cannot sleep as this can be called in interrupt context, > * so use this_cpu_cmpxchg to update the cache, and > vfree_atomic I'm not sure if we need to add kasan_unpoison_vmalloc() and kasan_poison_vmalloc() in this file. As far as I know, vmalloc() and vfree() will do these two functions. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel