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Since __hid_input_report() invokes the driver's raw_event callback before hid_report_raw_event() performs its own report-size validation, a device sending a truncated HID report can cause out-of-bounds heap reads in the kernel. The most critical access is the memcpy from data[50] into mcp->adc_values (6 bytes) when CONFIG_IIO is reachable. Other unchecked accesses include data[20] and a memcpy at data[22]. Additionally, a memcpy with device-controlled length (data[3], up to 60 bytes) from data[4] does not verify that size is large enough to cover the copy. MCP2221 devices use 64-byte HID reports. Add a check at the top of the handler to reject any report shorter than expected. Cc: stable@vger.kernel.org Signed-off-by: Sebastian Josue Alba Vives --- drivers/hid/hid-mcp2221.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c index ef3b5c77c..fcac37491 100644 --- a/drivers/hid/hid-mcp2221.c +++ b/drivers/hid/hid-mcp2221.c @@ -851,6 +851,10 @@ static int mcp2221_raw_event(struct hid_device *hdev, u8 *buf; struct mcp2221 *mcp = hid_get_drvdata(hdev); + /* MCP2221 always sends 64-byte reports */ + if (size < 64) + return 0; + switch (data[0]) { case MCP2221_I2C_WR_DATA: -- 2.43.0