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    SubjectRe: [PATCH] x86: add missing verify_cpu to 32bit wakeup
    Hi Pavel,

    On Sun, Jul 03, 2011 at 02:15:49PM +0200, Pavel Machek wrote:
    > > 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 <>
    > > Cc:
    > Looks ok to me, but I'm not sure it is stable material.

    Well, I figured anything that shipped with
    ebba638ae723d8a8fc2f7abce5ec18b688b791d7 should get it, since it is
    a regression in the 32bit PAE with BIOS-disabled NX corner-case.


    Kees Cook
    Ubuntu Security Team

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      Last update: 2011-07-03 21:21    [W:0.078 / U:18.124 seconds]
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