HID: lg4ff: validate report length before fixed offsets

lg4ff_raw_event() rewrites fixed report offsets when combined pedals are
enabled. It currently assumes that each product report contains every
source and destination byte used by the rewrite.

Return without rewriting a short report before each product-specific
access. Apply the same bound to the computed offset path.

Fixes: c832f86eff ("HID: hid-logitech: Add combined pedal support Logitech wheels")
Signed-off-by: Jiancheng Huang <jchuang@seu.edu.cn>
Assisted-by: Codex:gpt-5.6-luna
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This commit is contained in:
Jiancheng Huang
2026-07-24 20:19:17 +08:00
committed by Jiri Kosina
parent eb51c9f8cb
commit be00988cce

View File

@@ -336,6 +336,8 @@ int lg4ff_raw_event(struct hid_device *hdev, struct hid_report *report,
if (entry->wdata.combine) {
switch (entry->wdata.product_id) {
case USB_DEVICE_ID_LOGITECH_WHEEL:
if (size < 7)
return 0;
rd[5] = rd[3];
rd[6] = 0x7F;
return 1;
@@ -343,10 +345,14 @@ int lg4ff_raw_event(struct hid_device *hdev, struct hid_report *report,
case USB_DEVICE_ID_LOGITECH_WINGMAN_FFG:
case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL:
case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2:
if (size < 6)
return 0;
rd[4] = rd[3];
rd[5] = 0x7F;
return 1;
case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
if (size < 7)
return 0;
rd[5] = rd[4];
rd[6] = 0x7F;
return 1;
@@ -366,6 +372,8 @@ int lg4ff_raw_event(struct hid_device *hdev, struct hid_report *report,
}
/* Compute a combined axis when wheel does not supply it */
if (size <= offset + 1)
return 0;
rd[offset] = (0xFF + rd[offset] - rd[offset+1]) >> 1;
rd[offset+1] = 0x7F;
return 1;