Re: Backporting CVE-2020-3702 ath9k patches to stable

On Friday 20 August 2021 17:23:08 Sasha Levin wrote:

On Fri, Aug 20, 2021 at 01:35:05PM +0200, Pali Rohár wrote:

quoted

On Wednesday 18 August 2021 11:18:29 Greg KH wrote:

quoted

On Wed, Aug 18, 2021 at 11:10:27AM +0200, Pali Rohár wrote:

quoted

On Wednesday 18 August 2021 11:02:47 Greg KH wrote:

quoted

On Wed, Aug 18, 2021 at 10:48:59AM +0200, Pali Rohár wrote:

quoted

Hello! I would like to request for backporting following ath9k commits
which are fixing CVE-2020-3702 issue.

56c5485c9e44 ("ath: Use safer key clearing with key cache entries")
73488cb2fa3b ("ath9k: Clear key cache explicitly on disabling hardware")
d2d3e36498dd ("ath: Export ath_hw_keysetmac()")
144cd24dbc36 ("ath: Modify ath_key_delete() to not need full key entry")
ca2848022c12 ("ath9k: Postpone key cache entry deletion for TXQ frames reference it")

See also:
https://lore.kernel.org/linux-wireless/87o8hvlx5g.fsf@codeaurora.org/ (local)

This CVE-2020-3702 issue affects ath9k driver in stable kernel versions.
And due to this issue Qualcomm suggests to not use open source ath9k
driver and instead to use their proprietary driver which do not have
this issue.

Details about CVE-2020-3702 are described on the ESET blog post:
https://www.welivesecurity.com/2020/08/06/beyond-kr00k-even-more-wifi-chips-vulnerable-eavesdropping/

Two months ago ESET tested above mentioned commits applied on top of
4.14 stable tree and confirmed that issue cannot be reproduced anymore
with those patches. Commits were applied cleanly on top of 4.14 stable
tree without need to do any modification.

What stable tree(s) do you want to see these go into?

Commits were introduced in 5.12, so it should go to all stable trees << 5.12

quoted

And what order are the above commits to be applied in, top-to-bottom or
bottom-to-top?

Same order in which were applied in 5.12. So first commit to apply is
56c5485c9e44, then 73488cb2fa3b and so on... (from top of the email to
the bottom of email).

Great, all now queued up.  Sad that qcom didn't want to do this
themselves :(

greg k-h

It is sad, but Qualcomm support said that they have fixed it in their
proprietary driver in July 2020 (so more than year ago) and that open
source drivers like ath9k are unsupported and customers should not use
them :( And similar answer is from vendors who put these chips into
their cards / products.

Is there a public statement that says that? Right now the MAINTAINERS
file says it's "supported" and if it's not the case we should at least
fix that and consider deprecating it if it's really orphaned.

No, there is no public statement. This is just (private) response from
official Qualcomm support contact...

And from card vendors were similar replies, that they received only fix
from Qualcomm (for proprietary driver) and for open source ath9k support
I need to ask open source kernel community. They suggested me to wait
until open source kernel community fix it.

I really do not know what is the support state of ath9k, but the fact is
that this security issue was fixed in July 2020 (in Qualcomm driver) and
some vendors received fix even earlier.

So something is really wrong if in LTS kernels this issue was not fixed
for more than year and in vendor driver was it basically immediately.

I agree that some clarification or public statement about ath9k driver
support would be very useful...

-- 
Thanks,
Sasha