linux-kernel - Re: [PATCH v2] iTCO_wdt: mask NMI_NOW bit for update_no_reboot

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: <cc652ed1-32c7-4ea2-b494-698b344f24a0@roeck-us.net>
Date: Thu, 12 Sep 2024 14:15:54 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Oleksandr Ocheretnyi <oocheret@...co.com>
Cc: jdelvare@...e.de, linux-kernel@...r.kernel.org,
 linux-watchdog@...r.kernel.org, mika.westerberg@...ux.intel.com,
 wim@...ux-watchdog.org, wsa@...nel.org, xe-linux-external@...co.com
Subject: Re: [PATCH v2] iTCO_wdt: mask NMI_NOW bit for update_no_reboot_bit()
 call

On 9/12/24 07:19, Oleksandr Ocheretnyi wrote:
> Commit da23b6faa8bf ("watchdog: iTCO: Add support for Cannon Lake
> PCH iTCO") does not mask NMI_NOW bit during TCO1_CNT register's
> value comparison for update_no_reboot_bit() call causing following
> failure:
> 
>     ...
>     iTCO_vendor_support: vendor-support=0
>     iTCO_wdt iTCO_wdt: unable to reset NO_REBOOT flag, device
>                                      disabled by hardware/BIOS
>     ...
> 
> and this can lead to unexpected NMIs later during regular
> crashkernel's workflow because of watchdog probe call failures.
> 
> This change masks NMI_NOW bit for TCO1_CNT register values to
> avoid unexpected NMI_NOW bit inversions.
> 
> Fixes: da23b6faa8bf ("watchdog: iTCO: Add support for Cannon Lake PCH iTCO")
> Signed-off-by: Oleksandr Ocheretnyi <oocheret@...co.com>
> ---

Oh, and change log goes here.

Guenter