Re: [PATCH] x86: add missing verify_cpu to 32bit wakeup

From: Pavel Machek
Date: Sun Jul 03 2011 - 08:26:10 EST


Hi!

> Some BIOSes will reset the Intel XD_DISABLE MSR bit when resuming from S3,
> which can interact poorly with ebba638ae723d8a8fc2f7abce5ec18b688b791d7.
> In 32bit PAE mode, this can lead to a fault when EFER is restored by
> the kernel wakeup routines, due to it setting the NX bit for a CPU
> that (thanks to the BIOS reset) now incorrectly thinks it lacks the NX
> feature. 64bit wakeup already handled this through its common call path
> that would hit verify_cpu(). 32bit has a separate path for restoring
> CPU state on S3 wakeup, and needed to call verify_cpu() to handle this
> situation.
>
> Signed-off-by: Kees Cook <kees.cook@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxx

Looks ok to me, but I'm not sure it is stable material.
Pavel
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