[PATCH 4.4 40/41] HID: usbhid: free raw_report buffers in usbhid_stop

Greg Kroah-Hartman
2021-10-04T12:56:00Z

From: Anirudh Rayabharam <mail@anirudhrb.com>

commit f7744fa16b96da57187dc8e5634152d3b63d72de upstream.

Free the unsent raw_report buffers when the device is removed.

Fixes a memory leak reported by syzbot at:
https://syzkaller.appspot.com/bug?id=7b4fa7cb1a7c2d3342a2a8a6c53371c8c418ab47

Reported-by: syzbot+47b26cd837ececfc666d@syzkaller.appspotmail.com
Tested-by: syzbot+47b26cd837ececfc666d@syzkaller.appspotmail.com
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/hid/usbhid/hid-core.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -500,7 +500,7 @@ static void hid_ctrl(struct urb *urb)

if (unplug) {
usbhid->ctrltail = usbhid->ctrlhead;
- } else {
+ } else if (usbhid->ctrlhead != usbhid->ctrltail) {
usbhid->ctrltail = (usbhid->ctrltail + 1) & (HID_CONTROL_FIFO_SIZE - 1);

if (usbhid->ctrlhead != usbhid->ctrltail &&
@@ -1185,9 +1185,20 @@ static void usbhid_stop(struct hid_devic
usbhid->intf->needs_remote_wakeup = 0;

clear_bit(HID_STARTED, &usbhid->iofl);
+
spin_lock_irq(&usbhid->lock); /* Sync with error and led handlers */
set_bit(HID_DISCONNECTED, &usbhid->iofl);
+ while (usbhid->ctrltail != usbhid->ctrlhead) {
+ if (usbhid->ctrl[usbhid->ctrltail].dir == USB_DIR_OUT) {
+ kfree(usbhid->ctrl[usbhid->ctrltail].raw_report);
+ usbhid->ctrl[usbhid->ctrltail].raw_report = NULL;
+ }
+
+ usbhid->ctrltail = (usbhid->ctrltail + 1) &
+ (HID_CONTROL_FIFO_SIZE - 1);
+ }
spin_unlock_irq(&usbhid->lock);
+
usb_kill_urb(usbhid->urbin);
usb_kill_urb(usbhid->urbout);
usb_kill_urb(usbhid->urbctrl);