From nobody Sun Feb 8 18:32:29 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 3EAAE2DF152; Tue, 6 Jan 2026 10:01:50 +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=1767693710; cv=none; b=lbtCpV9+7qnfWkmBy8dmU1vkDCuH1Tg1Ys+AL+jl/h4rC1DpFVVps+lZwKLTPOEHXy58oQh8MzaX4s7dyKCx4/WRWMo2PEbfM/L7DLPOCca7olwQWeohKkzZuyzl2rghcoKb3t9va5RzRx7+N67zb6k/GG+ND5/FcxQpP82E55k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767693710; c=relaxed/simple; bh=3Avwk9ah4fvsu5pW2Hk/IxHeMU3rEwQMuWdy8ZlvDv0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=B6z9+aDeJ0AQtzkaINEdh5ScUnY00zO93+okPVqG6v9kuVJk+/wR37dSZ96ygojktEPSqbVVy4P3WWWjOQ6Jy7D7o7J0NXLG4s+GhXrnO1Mv61Ucev0VTYqyjTIL5eQHxHkYUR52Mw5RjH6g6D99m1DC1tVvOBIfPoY//yRoIaM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U/910rDE; 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="U/910rDE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB9ABC116C6; Tue, 6 Jan 2026 10:01:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767693709; bh=3Avwk9ah4fvsu5pW2Hk/IxHeMU3rEwQMuWdy8ZlvDv0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U/910rDE7bMhtYdfWx/jDSmtv0FxbwK2ijV5f/xtPl31v60lvsiU/O/g50dPbpMm3 0oGhriGXbYeXa4dzFfWW5unorQ56BmnIqujsK8mkjic0FoWY5NMH9wIT2xT3vkOqs4 NGOeJjkd8r7PPzV3zrgnwtyOqkMcRlFOdVLdfPVmNvi4GOHPbg7QjOfngB1c5k28P6 o+yCESIkb0l5KLVrgQrsRd9gEWnzerfBKVQyv8SUtp5/0nl2F7QKr+zLtm21xF0r/F nztqgBTqu1ED7EA3he/VAlxMfpuQk6ZYq4+tezzwA9YcvD2jd04lTFoM5TCR1T9Tx2 40NEGd8mb9y/Q== Received: from mchehab by mail.kernel.org with local (Exim 4.99) (envelope-from ) id 1vd3sq-000000008ZM-004n; Tue, 06 Jan 2026 11:01:48 +0100 From: Mauro Carvalho Chehab To: Ard Biesheuvel Cc: Mauro Carvalho Chehab , Dan Williams , Dave Jiang , Gregory Price , Jonathan Cameron , Smita Koralahalli , linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 2/4] efi/cper: don't go past the ARM processor CPER record buffer Date: Tue, 6 Jan 2026 11:01:36 +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-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Sender: Mauro Carvalho Chehab 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