Re: [PATCH] platform/x86: think-lmi: Fix "Call Trace" error warning

[Gou Tongchen]

On 7/7/26 21:31, Mark Pearson wrote:
Hi
> Hi
>
> On Tue, Jul 7, 2026, at 5:15 AM, goutongchen@xxxxxxxxxxxxx wrote:
> > From: goutongchen <goutongchen@xxxxxxxxxxxxx>
> >
> > The maximum BIOS password length returned by the Lenovo platform BIOS/WMI
> > exceeded the size assumed by the think_lmi driver's internal static
> > buffer, causing the driver to trigger a WARN_ON() during self-checks.
> >
> > Increase TLMI_PWD_BUFSIZE from 128 to 256 to eliminate the recurring
> > Call Trace warnings.
> >
> > Here is the kernel warning triggered by the bug:
> >
> >    kernel: WARNING: CPU: 4 PID: 665 at drivers/platform/x86/think-lmi.c:326
> >    kernel:        tlmi_get_pwd_settings.constprop.0+0xe6/0x130 [think_lmi]
> >    kernel: Call Trace:
> >    kernel:  tlmi_analyze+0x31c/0x640 [think_lmi]
> >    ...
> >
> > Fixes: 651b57dd4087 ("platform/x86: Move Lenovo files into lenovo subdir")
> Minor - but I don't think this is really the culprit :)
Gou Tongchen - Because it was initially discovered on an older kernel 
version, the path hadn't been changed at that time.
> > Signed-off-by: goutongchen <goutongchen@xxxxxxxxxxxxx>
> > ---
> >   drivers/platform/x86/lenovo/think-lmi.h | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/platform/x86/lenovo/think-lmi.h
> > b/drivers/platform/x86/lenovo/think-lmi.h
> > index 017644323d46..d643cf3b81b0 100644
> > --- a/drivers/platform/x86/lenovo/think-lmi.h
> > +++ b/drivers/platform/x86/lenovo/think-lmi.h
> > @@ -8,7 +8,7 @@
> >
> >   #define TLMI_SETTINGS_COUNT  256
> >   #define TLMI_SETTINGS_MAXLEN 512
> > -#define TLMI_PWD_BUFSIZE     129
> > +#define TLMI_PWD_BUFSIZE     256
> >   #define TLMI_LANG_MAXLEN       4
> >   #define TLMI_INDEX_MAX        32
> >
> > --
> > 2.20.1
> Which platform are you seeing this on please? The maxlen for passwords from the BIOS is supposed to be 128 so I'm intrigued as to where you're seeing different. It maybe should be fixed in a platform BIOS?
>
> Mark

The hardware platform is a Lenovo X7h with a Hygon 4 CPU. The specific model and BIOS version are as follows:

kernel: DMI: KaiTian /LXKT-HG4M-X7, BIOS W0WKT1FA 11/18/2025

I found through kernel log printing that the BIOS returned a password length of 255, so I increased TLMI_PWD_BUFSIZE to 256.

Thanks.

Gou Tongchen

>