From patchwork Tue Oct 15 15:26:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheng Zengkai X-Patchwork-Id: 13836600 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D9CB5D216BF for ; Tue, 15 Oct 2024 14:54:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=DaLTiHv/rdymEqE2sjMrq0eJcOGk2rx3XmF8d4nL/HY=; b=vGB/4fZdRkeq3fbttHg9cMfrUz ifCXY9oOawT0q/tZM/MjCf5d6psr2KmDmYxmNqZGpDfqlY3Xrg3d9+0aHVOqQsEEhNqi0rd+QWQlA 9SXr4bwcWF3lG8DTWCaDjSu5cA1uqZCHnHHGET/UnnFgXnnydtFv3WUmGlro3xwUgiKODYSOekQPK 6SOXDFRQsnnSD91QKy2oTE5IilSHq/j2jFwouczS634u9gB/B4oNqaAd4NLclYqE6vqlzoul99JDl 5ScM+wOYuzYVQQFLHxFDS8rG/991u3HquVX1PXuKohqZlejEqj75uW7AF8q6vgUbjnaJEXMMaRdwJ sSqnNG0w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t0iw5-00000008aT8-2kk6; Tue, 15 Oct 2024 14:54:09 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t0iue-00000008aEK-1fqJ for linux-arm-kernel@lists.infradead.org; Tue, 15 Oct 2024 14:52:42 +0000 Received: from mail.maildlp.com (unknown [172.19.163.17]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4XScR75WqCz1HL2t; Tue, 15 Oct 2024 22:48:19 +0800 (CST) Received: from kwepemd200010.china.huawei.com (unknown [7.221.188.124]) by mail.maildlp.com (Postfix) with ESMTPS id 333BB1A0188; Tue, 15 Oct 2024 22:52:32 +0800 (CST) Received: from huawei.com (10.175.113.25) by kwepemd200010.china.huawei.com (7.221.188.124) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 15 Oct 2024 22:52:31 +0800 From: Zheng Zengkai To: , , , , , , CC: , , , , , Subject: [PATCH v3] ACPI: GTDT: Tighten the check for the array of platform timer structures Date: Tue, 15 Oct 2024 23:26:02 +0800 Message-ID: <20241015152602.184108-1-zhengzengkai@huawei.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Originating-IP: [10.175.113.25] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemd200010.china.huawei.com (7.221.188.124) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241015_075240_976127_D27EAFB8 X-CRM114-Status: GOOD ( 18.10 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org As suggested by Marc and Lorenzo, first we need to check whether the platform_timer entry pointer is within gtdt bounds (< gtdt_end) before de-referencing what it points at to detect the length of the platform timer struct and then check that the length of current platform_timer struct is also valid, i.e. the length is not zero and within gtdt_end. Now next_platform_timer() only checks against gtdt_end for the entry of subsequent platform timer without checking the length of it and will not report error if the check failed and the existing check in function acpi_gtdt_init() is also not enough. Modify the for_each_platform_timer() iterator and use it combined with a dedicated check function platform_timer_valid() to do the check against table length (gtdt_end) for each element of platform timer array in function acpi_gtdt_init(), making sure that both their entry and length actually fit in the table. Suggested-by: Lorenzo Pieralisi Co-developed-by: Marc Zyngier Signed-off-by: Marc Zyngier Signed-off-by: Zheng Zengkai Reviewed-by: Lorenzo Pieralisi --- Changes in v3: - based on Marc's patch and reuse the for_each_platform_timer() loop Changes in v2: - Check against gtdt_end for both entry and len of each array element Link to v2: https://lore.kernel.org/linux-arm-kernel/20241012085343.6594-1-zhengzengkai@huawei.com/ Link to v1: https://lore.kernel.org/all/20241010144703.113728-1-zhengzengkai@huawei.com/ --- drivers/acpi/arm64/gtdt.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c index c0e77c1c8e09..3583c99afb0d 100644 --- a/drivers/acpi/arm64/gtdt.c +++ b/drivers/acpi/arm64/gtdt.c @@ -36,19 +36,25 @@ struct acpi_gtdt_descriptor { static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata; -static inline __init void *next_platform_timer(void *platform_timer) +static __init bool platform_timer_valid(void *platform_timer) { struct acpi_gtdt_header *gh = platform_timer; - platform_timer += gh->length; - if (platform_timer < acpi_gtdt_desc.gtdt_end) - return platform_timer; + return (platform_timer >= (void *)(acpi_gtdt_desc.gtdt + 1) && + platform_timer < acpi_gtdt_desc.gtdt_end && + gh->length != 0 && + platform_timer + gh->length <= acpi_gtdt_desc.gtdt_end); +} + +static __init void *next_platform_timer(void *platform_timer) +{ + struct acpi_gtdt_header *gh = platform_timer; - return NULL; + return platform_timer + gh->length; } -#define for_each_platform_timer(_g) \ - for (_g = acpi_gtdt_desc.platform_timer; _g; \ +#define for_each_platform_timer(_g, first_entry) \ + for (_g = first_entry; platform_timer_valid(_g); \ _g = next_platform_timer(_g)) static inline bool is_timer_block(void *platform_timer) @@ -155,8 +161,9 @@ bool __init acpi_gtdt_c3stop(int type) int __init acpi_gtdt_init(struct acpi_table_header *table, int *platform_timer_count) { - void *platform_timer; + void *platform_timer, *tmp; struct acpi_table_gtdt *gtdt; + int cnt = 0; gtdt = container_of(table, struct acpi_table_gtdt, header); acpi_gtdt_desc.gtdt = gtdt; @@ -177,7 +184,10 @@ int __init acpi_gtdt_init(struct acpi_table_header *table, } platform_timer = (void *)gtdt + gtdt->platform_timer_offset; - if (platform_timer < (void *)table + sizeof(struct acpi_table_gtdt)) { + for_each_platform_timer(tmp, platform_timer) + cnt++; + + if (cnt != gtdt->platform_timer_count) { pr_err(FW_BUG "invalid timer data.\n"); return -EINVAL; } @@ -305,7 +315,7 @@ int __init acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem, void *platform_timer; *timer_count = 0; - for_each_platform_timer(platform_timer) { + for_each_platform_timer(platform_timer, acpi_gtdt_desc.platform_timer) { if (is_timer_block(platform_timer)) { ret = gtdt_parse_timer_block(platform_timer, timer_mem); if (ret) @@ -398,7 +408,7 @@ static int __init gtdt_sbsa_gwdt_init(void) if (ret || !timer_count) goto out_put_gtdt; - for_each_platform_timer(platform_timer) { + for_each_platform_timer(platform_timer, acpi_gtdt_desc.platform_timer) { if (is_non_secure_watchdog(platform_timer)) { ret = gtdt_import_sbsa_gwdt(platform_timer, gwdt_count); if (ret)