Re: NULL pointer dereference in call_fext_func [fujitsu_laptop]

From: Jonathan Woithe
Date: Tue Sep 19 2017 - 04:20:18 EST

On Tue, Sep 19, 2017 at 09:56:47AM +0200, Jiri Slaby wrote:
> we have this report from 4.13.1:
> BUG: unable to handle kernel NULL pointer dereference at 00000004
> IP: call_fext_func.isra.3+0x82/0xf0 [fujitsu_laptop]
> *pdpt = 0000000035e79001 *pde = 0000000000000000
> :
> It looks like fext is NULL, but bl_update_status passes it down to
> call_fext_func which obviously blows up.
> This was originally reported here:

Thanks for the report.

This issue is already being discussed. See the platform drivers thread
"[PATCH] platform/x86: fujitsu-laptop: Don't oops when FUJ02E3 is not

> Any ideas?

Until the above post to platform drivers it was thought that all Fujitsu
laptops had FUJ02E3 since this was what was observed on all models we had
access to.

An interim patch is under consideration.