[PATCH 5.15 398/570] HID: wacom: fix out-of-bounds read in wacom_intuos_bt_irq

Greg Kroah-Hartman
2026-04-13T16:35:15Z

From: Benoît Sevens <bsevens@google.com>

[ Upstream commit 2f1763f62909ccb6386ac50350fa0abbf5bb16a9 ]

The wacom_intuos_bt_irq() function processes Bluetooth HID reports
without sufficient bounds checking. A maliciously crafted short report
can trigger an out-of-bounds read when copying data into the wacom
structure.

Specifically, report 0x03 requires at least 22 bytes to safely read
the processed data and battery status, while report 0x04 (which
falls through to 0x03) requires 32 bytes.

Add explicit length checks for these report IDs and log a warning if
a short report is received.

Signed-off-by: Benoît Sevens <bsevens@google.com>
Reviewed-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hid/wacom_wac.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 0ab473f372ad0..0cc979d99b3d8 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -1258,10 +1258,20 @@ static int wacom_intuos_bt_irq(struct wacom_wac *wacom, size_t len)

switch (data[0]) {
case 0x04:
+ if (len < 32) {
+ dev_warn(wacom->pen_input->dev.parent,
+ "Report 0x04 too short: %zu bytes\n", len);
+ break;
+ }
wacom_intuos_bt_process_data(wacom, data + i);
i += 10;
fallthrough;
case 0x03:
+ if (i == 1 && len < 22) {
+ dev_warn(wacom->pen_input->dev.parent,
+ "Report 0x03 too short: %zu bytes\n", len);
+ break;
+ }
wacom_intuos_bt_process_data(wacom, data + i);
i += 10;
wacom_intuos_bt_process_data(wacom, data + i);
--
2.53.0