In the Linux kernel, the following vulnerability has been resolved:
HID: nintendo: fix out-of-bounds read in joyconctlrread_handler()
joyconctlrreadhandler() casts an incoming HID input report to struct joyconinput_report and parses it, guarding the cast only with a 12-byte length check:
if (size >= 12) /* make sure it contains the input report */
joycon_parse_report(ctlr, (struct joycon_input_report *)data);
struct joyconinputreport is 49 bytes: a 13-byte header followed by a union whose IMU arm is 36 bytes. For an IMU report joyconparsereport() -> joyconparseimureport() walks that union (struct offsets 13..48), so a report of exactly 12 bytes with data[0] == JCINPUTIMUDATA passes the guard yet is read up to 37 bytes past its declared length. The over-read bytes are decoded into accelerometer/gyroscope values and forwarded to userspace through the "(IMU)" input device, leaking driver-internal memory. data[0] and size are fully controlled by a malicious or spoofed Joy-Con/Pro Controller.
Receive buffers are sized to the maximum report length, so this is an over-read within the allocation rather than a slab OOB, but the decoded bytes still reach userspace.
The sibling subcmd path in joyconctlrhandle_event() already bounds the same cast correctly:
if (size < sizeof(struct joycon_input_report) ||
data[0] != JC_INPUT_SUBCMD_REPLY)
break;
Use the same sizeof(struct joyconinputreport) bound here.