2021-06-23 18:42:42

by Anirudh Rayabharam

Subject: [PATCH] usbhid: free raw_report buffers in usbhid_stop

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: [email protected]
Tested-by: [email protected]
Signed-off-by: Anirudh Rayabharam <[email protected]>
---
drivers/hid/usbhid/hid-core.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 4e9077363c96..9c970e63670e 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -505,7 +505,7 @@ 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 &&
@@ -1223,9 +1223,20 @@ static void usbhid_stop(struct hid_device *hid)
mutex_lock(&usbhid->mutex);

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);
--
2.26.2

2021-07-28 09:33:58

by Jiri Kosina

Subject: Re: [PATCH] usbhid: free raw_report buffers in usbhid_stop

On Thu, 24 Jun 2021, Anirudh Rayabharam wrote:

> 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: [email protected]
> Tested-by: [email protected]
> Signed-off-by: Anirudh Rayabharam <[email protected]>

Applied, thank you.

--
Jiri Kosina
SUSE Labs