From 26ce0e6bf0b27fc6a2f490f38555dfd0a27c9605 Mon Sep 17 00:00:00 2001 From: Jiale Yao Date: Thu, 24 Sep 2026 22:44:09 +0800 Subject: [PATCH] HID: mcp2200: validate READ_ALL response length The HID core invokes raw_event callbacks before validating the report length. mcp2200_raw_event() casts a READ_ALL response to struct mcp_read_all_resp and reads fields through offset ten without checking that the response contains the structure. A one-byte READ_ALL response reproduced the issue under KASAN: BUG: KASAN: slab-out-of-bounds in mcp2200_raw_event+0x24b/0x3a0 Read of size 1 by task hidtrigger/89 Call Trace: mcp2200_raw_event+0x24b/0x3a0 kasan_report+0x139/0x170 Reject an incomplete READ_ALL response with a protocol error before reading its fields. The common completion path then wakes the command waiter with the error instead of leaving it to time out. Commit 47669bec44fe ("HID: asus: refactor the two workqueues and init sequence") added the same kind of raw_event length validation to hid-asus. Fixes: 740329d7120f ("HID: mcp2200: added driver for GPIOs of MCP2200") Cc: stable@vger.kernel.org Signed-off-by: Jiale Yao Signed-off-by: Jiri Kosina --- drivers/hid/hid-mcp2200.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/hid/hid-mcp2200.c b/drivers/hid/hid-mcp2200.c index dafdd5b4a079..c6fd5fb5d578 100644 --- a/drivers/hid/hid-mcp2200.c +++ b/drivers/hid/hid-mcp2200.c @@ -301,6 +301,11 @@ static int mcp2200_raw_event(struct hid_device *hdev, struct hid_report *report, switch (data[0]) { case READ_ALL: + if (size < sizeof(*all_resp)) { + mcp->status = -EPROTO; + break; + } + all_resp = (struct mcp_read_all_resp *) data; mcp->status = 0; mcp->gpio_inval = all_resp->io_port_val_bmap;