From patchwork Wed Oct 16 09:54:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheng Zengkai X-Patchwork-Id: 835870 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4AB5D1D90DD; Wed, 16 Oct 2024 09:21:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729070495; cv=none; b=L5lx18YhiNvAOCR1BAzYHs9S2bNm0Scn4uPUQZWzZX5xgPsPJ5DdqoLiF1qSrwJxxgkq6pN6w55RLL2iTfFzPw/h4Jd2cE869vrEPpEiGDwPnKzl3jNcTHWDRHRxmnwQeCapqof8H2GazrgZRFPfIChFcyMVg8Wc/GnIYFHAyLQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729070495; c=relaxed/simple; bh=re5iF3yVOjF2BgRHj3pjVBxIhCLycoiqhjrd3dLPAvA=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=VEZO9uhRG7t76266zyHEhSAcxKk7SZME/udVFzt3kyW71vRxnqjlUBEgAc/jxEkgntoNjytmrt3+E5XD6iqHJtgKpTr7Cuj/qVxh6OrV9FSMNigxlgvsRbZYSy6STv/rMq2/0FM/WQhEwMRY3RtYY51VJWa8cqeuqTEbORZywWg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.105]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4XT55J22WtzpX4f; Wed, 16 Oct 2024 17:19:32 +0800 (CST) Received: from kwepemd200010.china.huawei.com (unknown [7.221.188.124]) by mail.maildlp.com (Postfix) with ESMTPS id A30DD1402C8; Wed, 16 Oct 2024 17:21:30 +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; Wed, 16 Oct 2024 17:21:29 +0800 From: Zheng Zengkai To: , , , , , , CC: , , , , , Subject: [PATCH v4] ACPI: GTDT: Tighten the check for the array of platform timer structures Date: Wed, 16 Oct 2024 17:54:58 +0800 Message-ID: <20241016095458.34126-1-zhengzengkai@huawei.com> X-Mailer: git-send-email 2.20.1 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemd200010.china.huawei.com (7.221.188.124) 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: Hanjun Guo Tested-by: Hanjun Guo --- Changes in v4: - remove the tmp pointer to make the code more concise. Changes in v3: - based on Marc's patch and reuse the for_each_platform_timer() loop Link to v3: https://lore.kernel.org/linux-arm-kernel/20241015152602.184108-1-zhengzengkai@huawei.com/ 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/ Link to previous related patches: https://lore.kernel.org/all/20241008082429.33646-1-zhengzengkai@huawei.com/ https://lore.kernel.org/all/20240930030716.179992-1-zhengzengkai@huawei.com/ --- drivers/acpi/arm64/gtdt.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c index c0e77c1c8e09..d7c4e1b9915b 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; \ + for (_g = acpi_gtdt_desc.platform_timer; platform_timer_valid(_g);\ _g = next_platform_timer(_g)) static inline bool is_timer_block(void *platform_timer) @@ -157,6 +163,7 @@ int __init acpi_gtdt_init(struct acpi_table_header *table, { void *platform_timer; struct acpi_table_gtdt *gtdt; + int cnt = 0; gtdt = container_of(table, struct acpi_table_gtdt, header); acpi_gtdt_desc.gtdt = gtdt; @@ -176,12 +183,16 @@ int __init acpi_gtdt_init(struct acpi_table_header *table, return 0; } - platform_timer = (void *)gtdt + gtdt->platform_timer_offset; - if (platform_timer < (void *)table + sizeof(struct acpi_table_gtdt)) { + acpi_gtdt_desc.platform_timer = (void *)gtdt + gtdt->platform_timer_offset; + for_each_platform_timer(platform_timer) + cnt++; + + if (cnt != gtdt->platform_timer_count) { + acpi_gtdt_desc.platform_timer = NULL; pr_err(FW_BUG "invalid timer data.\n"); return -EINVAL; } - acpi_gtdt_desc.platform_timer = platform_timer; + if (platform_timer_count) *platform_timer_count = gtdt->platform_timer_count;