Re: [PATCH 6.12.y] HID: core: Mitigate potential OOB by removing bogus memset()

[Lee Jones <lee@kernel.org>]

On Wed, 03 Jun 2026, Wenshan Lan wrote:

> 
> On 6/3/2026 3:04 PM, Benjamin Tissoires wrote:
> > On Jun 03 2026, Wenshan Lan wrote:
> > > From: Lee Jones <lee@kernel.org>
> > > 
> > > [ Upstream commit 0a3fe972a7cb1404f693d6f1711f32bc1d244b1c ]
> > > 
> > > The memset() in hid_report_raw_event() has the good intention of
> > > clearing out bogus data by zeroing the area from the end of the incoming
> > > data string to the assumed end of the buffer.  However, as we have
> > > previously seen, doing so can easily result in OOB reads and writes in
> > > the subsequent thread of execution.
> > > 
> > > The current suggestion from one of the HID maintainers is to remove the
> > > memset() and simply return if the incoming event buffer size is not
> > > large enough to fill the associated report.
> > > 
> > > Suggested-by Benjamin Tissoires <bentiss@kernel.org>
> > > 
> > > Signed-off-by: Lee Jones <lee@kernel.org>
> > > [bentiss: changed the return value]
> > > Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
> > > [ Replace hid_warn_ratelimited() with hid_warn() in v6.12. ]
> > > Signed-off-by: Wenshan Lan <jetlan9@163.com>
> > > ---
> > This commit is known for breaking devices. You can't backport this
> > without the following 3 fixes:
> > 4d3a2a466b8d ("HID: core: Fix size_t specifier in hid_report_raw_event()")
> > 206342541fc8 ("HID: core: introduce hid_safe_input_report()")
> > 2c85c61d1332 ("HID: pass the buffer size to hid_report_raw_event")
> > 
> > Note that this is the same for your 6.6, 6.1 and 5.15 patches.
> 
> Thanks for your suggestion, I will send a V2 later.

https://lore.kernel.org/all/20260601083642.908433-1-lee@kernel.org/

-- 
Lee Jones