Re: CVE-2024-26827: i2c: qcom-geni: Correct I2C TRE sequence

[Jean Delvare <jdelvare@suse.de>]

On Thu, 2024-04-18 at 15:05 +0200, Greg Kroah-Hartman wrote:
> On Thu, Apr 18, 2024 at 02:56:33PM +0200, Jean Delvare wrote:
> > Hi Greg,
> > 
> > On Wed, 2024-04-17 at 11:44 +0200, Greg Kroah-Hartman wrote:
> > > Description
> > > ===========
> > > 
> > > In the Linux kernel, the following vulnerability has been resolved:
> > > 
> > > i2c: qcom-geni: Correct I2C TRE sequence
> > > 
> > > For i2c read operation in GSI mode, we are getting timeout
> > > due to malformed TRE basically incorrect TRE sequence
> > > in gpi(drivers/dma/qcom/gpi.c) driver.
> > > (...)
> > 
> > I was assigned the task to backport this security fix to the SUSE
> > kernels. However, from the description, I fail to see how this fix
> > qualifies as a security fix. I can't find the reason why a CVE was
> > assigned to the issue.
> > 
> > What is the considered attack vector? Or if there is no attack vector,
> > what consequence does this bug have, which would put the system
> > security at stake?
> 
> We reviewed this commit as fitting the fact that timeouts due to
> malformed messages would fit into the definition of "vulnerability" in
> the CVE world as it would cause a system to incure "negative impact to
> confidentiality, integrity, or availability".

If the timeout could be triggered on purpose, then I would agree, as
this could possibly be used for a denial-of-service type of attack. But
this isn't the case here.

All we have is a failure to read data from a random I2C device due to
an incorrect programming of the I2C controller. Simple lack of
functionality.

> If as the i2c maintainer, you don't think this would be the case, we
> will be glad to revoke this CVE and just mark it down as a "normal
> bugfix".

Yes, please.


-- 
Jean Delvare
SUSE L3 Support