From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 1D15A30FC30; Mon, 8 Dec 2025 15:55:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765209333; cv=none; b=SK3qcgKrvPiat75zaghICw4Wmq3RCuJXjYgKirfAhmGR2OAJSEvs+af2cLvxMbhH0QtRpB0gz/VIw0o9/w9vta6nBFejUiGA9V27rxRktXm3RC396yBwkh3VKdAsNbJgTKULmKXHfcPxKZ4mB87JxvQNlECFm1i98TMZmhkb1ng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765209333; c=relaxed/simple; bh=RYT1iy3FBB6uZoZKycGu/YHF0Dzox5/SlFNTtF6/wMw=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GsrxDv/RCnoIXes4+4YXXL9TG0FHzWlvXR1/pU3RXfQJgEmzFtrWXIfPJGIwj0uCwq5wHvrGcDHKliyrgVybc6NizEwMSScP+isV8N+B/OJJyjQ/UAjq0OJMEwvdxYDzcSbD6G4f2RYLTSnRB/Kczg0I5ozRDOVuJZz4J30HI80= 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=185.176.79.56 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 [172.18.224.107]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dQ64t1wCRzJ46XJ; Mon, 8 Dec 2025 23:55:10 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 2E5224056E; Mon, 8 Dec 2025 23:55:25 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Mon, 8 Dec 2025 15:55:24 +0000 Date: Mon, 8 Dec 2025 15:55:22 +0000 From: Jonathan Cameron To: Mauro Carvalho Chehab CC: "Rafael J. Wysocki" , Ard Biesheuvel , Borislav Petkov , Breno Leitao , Dave Jiang , Fan Ni , Hanjun Guo , Huang Yiwei , Ira Weiny , Jason Tian , Len Brown , "Mauro Carvalho Chehab" , Peter Zijlstra , Shuai Xue , "Smita Koralahalli" , Tony Luck , , , Subject: Re: [PATCH v2 1/2] apei/ghes: don't go past the ARM processor CPER record buffer Message-ID: <20251208155522.0000162e@huawei.com> In-Reply-To: <0f03f383fa76e41747b95713d50350be21867ccb.1764326826.git.mchehab+huawei@kernel.org> References: <0f03f383fa76e41747b95713d50350be21867ccb.1764326826.git.mchehab+huawei@kernel.org> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500011.china.huawei.com (7.191.174.215) To dubpeml100005.china.huawei.com (7.214.146.113) On Fri, 28 Nov 2025 11:53:00 +0100 Mauro Carvalho Chehab wrote: > There's a logic inside ghes/cper to detect if the section_length > is too small, but it doesn't detect if it is too big. > > Currently, if the firmware receives an ARM processor CPER record > stating that a section length is big, kernel will blindly trust > section_lentgh, producing a very long dump. For instance, a 67 section_length > bytes record with ERR_INFO_NUM set 46198 and section length > set to 854918320 would dump a lot of data going a way past the > firmware memory-mapped area. > > Fix it by adding a logic to prevent it to go past the buffer > if ERR_INFO_NUM is too big, making it report instead: > > [Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 1 > [Hardware Error]: event severity: recoverable > [Hardware Error]: Error 0, type: recoverable > [Hardware Error]: section_type: ARM processor error > [Hardware Error]: MIDR: 0xff304b2f8476870a > [Hardware Error]: section length: 854918320, CPER size: 67 > [Hardware Error]: section length is too big > [Hardware Error]: firmware-generated error record is incorrect > [Hardware Error]: ERR_INFO_NUM is 46198 > > Signed-off-by: Mauro Carvalho Chehab > --- > drivers/acpi/apei/ghes.c | 13 +++++++++++++ > drivers/firmware/efi/cper-arm.c | 14 +++++++++----- > drivers/firmware/efi/cper.c | 3 ++- > include/linux/cper.h | 3 ++- > 4 files changed, 26 insertions(+), 7 deletions(-) > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index 56107aa00274..8b90b6f3e866 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -557,6 +557,7 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, > { > struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata); > int flags = sync ? MF_ACTION_REQUIRED : 0; > + int length = gdata->error_data_length; > char error_type[120]; > bool queued = false; > int sec_sev, i; > @@ -568,7 +569,12 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, > return false; > > p = (char *)(err + 1); > + length -= sizeof(err); > + > for (i = 0; i < err->err_info_num; i++) { > + if (length <= 0) > + break; > + > struct cper_arm_err_info *err_info = (struct cper_arm_err_info *)p; > bool is_cache = err_info->type & CPER_ARM_CACHE_ERROR; > bool has_pa = (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR); > @@ -580,10 +586,17 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, > * and don't filter out 'corrected' error here. > */ > if (is_cache && has_pa) { > + length -= err_info->length; > + if (length < 0) > + break; > queued = ghes_do_memory_failure(err_info->physical_fault_addr, flags); > p += err_info->length; > + > continue; > } > + length -= err_info->length; > + if (length < 0) Indent odd. > + break; > > cper_bits_to_str(error_type, sizeof(error_type), > FIELD_GET(CPER_ARM_ERR_TYPE_MASK, err_info->type),