Re: CVE-2025-21991: x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes

Re: CVE-2025-21991: x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes

[Siddh Raman Pant]

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On Wed, 2 Apr 2025 13:51:58 +0100, Greg Kroah-Hartman wrote:
> In the Linux kernel, the following vulnerability has been resolved:
> 
> x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes
> 
> [...]
> 
> This does not have any security implications since flashing microcode is
> a privileged operation but I believe this has reliability implications by
> potentially corrupting memory while flashing a microcode update.

If it is explicitly specified that this does not have any security
implication, why is this a CVE?

IMO this should be rejected.

Thanks,
Siddh

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Re: CVE-2025-21991: x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes

[gregkh]

On Wed, Jun 04, 2025 at 09:24:12AM +0000, Siddh Raman Pant wrote:
> On Wed, 2 Apr 2025 13:51:58 +0100, Greg Kroah-Hartman wrote:
> > In the Linux kernel, the following vulnerability has been resolved:
> > 
> > x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes
> > 
> > [...]
> > 
> > This does not have any security implications since flashing microcode is
> > a privileged operation but I believe this has reliability implications by
> > potentially corrupting memory while flashing a microcode update.
> 
> If it is explicitly specified that this does not have any security
> implication, why is this a CVE?
> 
> IMO this should be rejected.

Doesn't "causing corrupted memory when flashing a microcode update" fit
the cve.org definition of a "vulnerabilty"?

thanks,

greg k-h

Re: CVE-2025-21991: x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes

[Siddh Raman Pant]

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On Wed, Jun 04 2025 at 14:58:03 +0530, gregkh@linuxfoundation.org
wrote:
> Doesn't "causing corrupted memory when flashing a microcode update" fit
> the cve.org definition of a "vulnerabilty"?

This only happens on CPU bring-up so I don't see it getting triggered
without already being exploited.

Thanks,
Siddh

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Re: CVE-2025-21991: x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes

[gregkh]

On Wed, Jun 04, 2025 at 09:54:55AM +0000, Siddh Raman Pant wrote:
> On Wed, Jun 04 2025 at 14:58:03 +0530, gregkh@linuxfoundation.org
> wrote:
> > Doesn't "causing corrupted memory when flashing a microcode update" fit
> > the cve.org definition of a "vulnerabilty"?
> 
> This only happens on CPU bring-up so I don't see it getting triggered
> without already being exploited.

If you can get the maintainers/developers involved with this change to
agree, we will be glad to reject this.

thanks,

greg k-h

Re: CVE-2025-21991: x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes

[Siddh Raman Pant]

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On Wed, Jun 04 2025 at 15:30:54 +0530, gregkh@linuxfoundation.org
wrote:
> On Wed, Jun 04, 2025 at 09:54:55AM +0000, Siddh Raman Pant wrote:
> > On Wed, Jun 04 2025 at 14:58:03 +0530, gregkh@linuxfoundation.org
> > wrote:
> > > Doesn't "causing corrupted memory when flashing a microcode update" fit
> > > the cve.org definition of a "vulnerabilty"?
> > 
> > This only happens on CPU bring-up so I don't see it getting triggered
> > without already being exploited.
> 
> If you can get the maintainers/developers involved with this change to
> agree, we will be glad to reject this.

Oops, went through it in more detail, you are right.

I should have done my homework better.

Very sorry for the noise,
Siddh

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