From: Kwok Kin Ming Date: Wed, 31 Dec 2025 18:18:26 +0000 (+0800) Subject: HID: i2c-hid: fix potential buffer overflow in i2c_hid_get_report() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2497ff38c530b1af0df5130ca9f5ab22c5e92f29;p=thirdparty%2Fkernel%2Flinux.git HID: i2c-hid: fix potential buffer overflow in i2c_hid_get_report() `i2c_hid_xfer` is used to read `recv_len + sizeof(__le16)` bytes of data into `ihid->rawbuf`. The former can come from the userspace in the hidraw driver and is only bounded by HID_MAX_BUFFER_SIZE(16384) by default (unless we also set `max_buffer_size` field of `struct hid_ll_driver` which we do not). The latter has size determined at runtime by the maximum size of different report types you could receive on any particular device and can be a much smaller value. Fix this by truncating `recv_len` to `ihid->bufsize - sizeof(__le16)`. The impact is low since access to hidraw devices requires root. Signed-off-by: Kwok Kin Ming Signed-off-by: Benjamin Tissoires --- diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index 63f46a2e5788..5a183af3d5c6 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -286,6 +286,7 @@ static int i2c_hid_get_report(struct i2c_hid *ihid, * In addition to report data device will supply data length * in the first 2 bytes of the response, so adjust . */ + recv_len = min(recv_len, ihid->bufsize - sizeof(__le16)); error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, ihid->rawbuf, recv_len + sizeof(__le16)); if (error) {