[PATCH] HID: uhid: convert to hid_safe_input_report()

[Carlos Llamas <cmllamas@google.com>]

Commit 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing
bogus memset()"), added a check in hid_report_raw_event() to reject
reports if the received data size is smaller than expected. This was
intended to prevent OOB errors by no longer allowing zeroing-out of
shorter reports due to the lack of buffer size information.

However, this leads to regressions in hid_report_raw_event(), where
shorter than expected reports are rejected, even though their buffers
are sufficiently large to be zero-padded.

To solve this issue, Benjamin introduced a safer alternative in commit
206342541fc8 ("HID: core: introduce hid_safe_input_report()"), which
forwards the buffer size and allows hid_report_raw_event() to safely
zero-pad the data.

Convert uhid to use hid_safe_input_report() and pass UHID_DATA_MAX as
the buffer size. This prevents the reported regressions [1], allowing
hid core to zero-pad the shorter reports safely as expected.

Cc: stable@vger.kernel.org
Fixes: 0a3fe972a7cb ("HID: core: Mitigate potential OOB by removing bogus memset()")
Closes: https://lore.kernel.org/all/ahsh0UtTX6e0ZeHa@google.com/ [1]
Signed-off-by: Carlos Llamas <cmllamas@google.com>
---
 drivers/hid/uhid.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 524b53a3c87b..37b60c3aaf66 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -595,8 +595,8 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
 	if (!READ_ONCE(uhid->running))
 		return -EINVAL;
 
-	hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data,
-			 min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0);
+	hid_safe_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data, UHID_DATA_MAX,
+			      min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0);
 
 	return 0;
 }
@@ -606,8 +606,8 @@ static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
 	if (!READ_ONCE(uhid->running))
 		return -EINVAL;
 
-	hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
-			 min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
+	hid_safe_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data, UHID_DATA_MAX,
+			      min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
 
 	return 0;
 }
-- 
2.54.0.1032.g2f8565e1d1-goog