From nobody Mon Feb 9 10:29:46 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 45FB82F6928; Fri, 19 Dec 2025 10:41:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766140866; cv=none; b=CxyOdZLxDyPaThwuRSN/QRxl2P1FPp3FunC8reN1Aa0RH1K9Sq/eK5IKlPgqy6PnQij1Cqoumgtp8HoqVbhetxqJfgL2S42GTAELGckbEkVRJ6RrwZUtDl00leWLHbcWMw+635RmPb2i3TecGpGV0F3xuC0NQoeqUZrWIMDQfxc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766140866; c=relaxed/simple; bh=pjJIBdeGr/2HUnvT1qt1BXIGueYL8pPwlvX7pDcJC/U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pKJsJ78K3TyVQs3iB/FhVldtjKr2xINdT5U2q+mRqKfIqdiB/MbG9hcfcRNNCf/ZlwiPPayDSpdf1q0kP0LRmQLqVrlDhSXUpQSqVo0XyU6oWLgN84o8uCS8TxWQX12/8XlfCMs5gOrLpNTrJBcz1LwecSkxpwUf+4shm84d7FQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aRM2m+J7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aRM2m+J7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8278C116D0; Fri, 19 Dec 2025 10:41:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766140865; bh=pjJIBdeGr/2HUnvT1qt1BXIGueYL8pPwlvX7pDcJC/U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aRM2m+J7tNKKhZU5aJNvPmNCyHID+lL07a06UMgrbLNP3BMBGSiby8ntNjUhNPv9V b30CI8suXkOQbrIFpJduqwF6ULwwJmyEnGQA1hU7NuDGJXkhD0F4bF7vvFcyQ2+0BZ LHo3JOPpSoJrDbR/a6ROMvImUkOrr/+aXFaxOofz1vHBBhaK8kSRb3U/UZBZwZdj9O VhN6OTLLoKITfV8kiCYCBhRahq9KfxkSK1OdbCdeM9X9maxBgLUj8DTJJ/u6yQQ911 ++tTcbHBzuGCQM9JzXtyfQMjfJF2FIdgLH/q6D3UEtKyHh+gI367VScwbalbO//z+k LnjgTTRtwDfYg== Received: from mchehab by mail.kernel.org with local (Exim 4.99) (envelope-from ) id 1vWXux-00000005ktu-45Mz; Fri, 19 Dec 2025 11:41:03 +0100 From: Mauro Carvalho Chehab To: "Rafael J. Wysocki" Cc: Mauro Carvalho Chehab , "Ard Biesheuvel" , "Borislav Petkov" , "Dave Jiang" , "Fan Ni" , "Jonathan Cameron" , "Shuai Xue" , "Smita Koralahalli" , linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] efi/cper: don't go past the ARM processor CPER record buffer Date: Fri, 19 Dec 2025 11:40:44 +0100 Message-ID: X-Mailer: git-send-email 2.52.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: Mauro Carvalho Chehab Content-Type: text/plain; charset="utf-8" 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_length, producing a very long dump. For instance, a 67 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 Reviewed-by: Jonathan Cameron --- drivers/firmware/efi/cper-arm.c | 12 ++++++++---- drivers/firmware/efi/cper.c | 3 ++- include/linux/cper.h | 3 ++- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/firmware/efi/cper-arm.c b/drivers/firmware/efi/cper-ar= m.c index 76542a53e202..b21cb1232d82 100644 --- a/drivers/firmware/efi/cper-arm.c +++ b/drivers/firmware/efi/cper-arm.c @@ -226,7 +226,8 @@ static void cper_print_arm_err_info(const char *pfx, u3= 2 type, } =20 void cper_print_proc_arm(const char *pfx, - const struct cper_sec_proc_arm *proc) + const struct cper_sec_proc_arm *proc, + u32 length) { int i, len, max_ctx_type; struct cper_arm_err_info *err_info; @@ -238,9 +239,12 @@ void cper_print_proc_arm(const char *pfx, =20 len =3D proc->section_length - (sizeof(*proc) + proc->err_info_num * (sizeof(*err_info))); - if (len < 0) { - printk("%ssection length: %d\n", pfx, proc->section_length); - printk("%ssection length is too small\n", pfx); + + if (len < 0 || proc->section_length > length) { + printk("%ssection length: %d, CPER size: %d\n", + pfx, proc->section_length, length); + printk("%ssection length is too %s\n", pfx, + (len < 0) ? "small" : "big"); printk("%sfirmware-generated error record is incorrect\n", pfx); printk("%sERR_INFO_NUM is %d\n", pfx, proc->err_info_num); return; diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c index 0232bd040f61..88fc0293f876 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -659,7 +659,8 @@ cper_estatus_print_section(const char *pfx, struct acpi= _hest_generic_data *gdata =20 printk("%ssection_type: ARM processor error\n", newpfx); if (gdata->error_data_length >=3D sizeof(*arm_err)) - cper_print_proc_arm(newpfx, arm_err); + cper_print_proc_arm(newpfx, arm_err, + gdata->error_data_length); else goto err_section_too_small; #endif diff --git a/include/linux/cper.h b/include/linux/cper.h index 5b1236d8c65b..440b35e459e5 100644 --- a/include/linux/cper.h +++ b/include/linux/cper.h @@ -595,7 +595,8 @@ void cper_mem_err_pack(const struct cper_sec_mem_err *, const char *cper_mem_err_unpack(struct trace_seq *, struct cper_mem_err_compact *); void cper_print_proc_arm(const char *pfx, - const struct cper_sec_proc_arm *proc); + const struct cper_sec_proc_arm *proc, + u32 length); void cper_print_proc_ia(const char *pfx, const struct cper_sec_proc_ia *proc); int cper_mem_err_location(struct cper_mem_err_compact *mem, char *msg); --=20 2.52.0