Re: CVE-2025-38495: HID: core: ensure the allocated report buffer can contain the reserved report ID

[gregkh@xxxxxxxxxxxxxxxxxxx]

On Tue, Sep 30, 2025 at 11:32:25AM +0000, Siddh Raman Pant wrote:
> On Tue, Sep 30 2025 at 16:52:30 +0530, gregkh@xxxxxxxxxxxxxxxxxxx
> wrote:
> > Is the CVE referenced here in the Subject line, and the git id it
> > references not valid?
> 
> It is valid.

Great!

> > Is there some other commit that also fixes a vulnerability
> > that should also be assigned to a new CVE?
> 
> Yes: 0d0777ccaa2d46609d05b66ba0096802a2746193 which is immediately
> after the commit in title, and fixes the underflow reported by
> syzkaller (see [1] and the commit message for the tested-by), which is
> the main bug, for which there is also a public exploit (see [2]).
> 
> [1] https://lore.kernel.org/all/686bb229.a00a0220.c7b3.0081.GAE@xxxxxxxxxx/t/#u
> 
> [2] https://github.com/xairy/kernel-exploits/tree/master/CVE-2025-38494

That is assigned to, and stopped by commit c2ca42f190b6 ("HID: core: do
not bypass hid_hw_raw_request"), so that should be fine.  And yes, you
do need to have commit 0d0777ccaa2d ("HID: core: ensure __hid_request
reserves the report ID as the first byte") applied in order to be able
to apply c2ca42f190b6 ("HID: core: do not bypass hid_hw_raw_request"),
but that's the case for MANY CVE ids that we call out, right?

Again, never cherry-pick :)

thanks,

greg k-h