linux-kernel - Re: [PATCH v5 4/4] efi/cper: don't dump the entire memory region

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260107175306.00005d5c@huawei.com>
Date: Wed, 7 Jan 2026 17:53:06 +0000
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
CC: "Rafael J. Wysocki" <rafael@...nel.org>, Ard Biesheuvel <ardb@...nel.org>,
	<acpica-devel@...ts.linux.dev>, <linux-acpi@...r.kernel.org>,
	<linux-edac@...r.kernel.org>, <linux-efi@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v5 4/4] efi/cper: don't dump the entire memory region

On Wed,  7 Jan 2026 17:41:52 +0100
Mauro Carvalho Chehab <mchehab+huawei@...nel.org> wrote:

> The current logic at cper_print_fw_err() doesn't check if the
> error record length is big enough to handle offset. On a bad firmware,
> if the ofset is above the actual record, length -= offset will
> underflow, making it dump the entire memory.
> 
> The end result can be:
> 
> - the logic taking a lot of time dumping large regions of memory;
> - data disclosure due to the memory dumps;
> - an OOPS, if it tries to dump an unmapped memory region.
> 
> Fix it by checking if the section length is too small before doing
> a hex dump.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>