[PATCH v3] can: usb: etas_es58x: Fix RX buffer leak on URB resubmit failure

[Guangshuo Li]

es58x_read_bulk_callback() resubmits the RX URB after processing a
received packet. If the resubmit succeeds, the URB remains anchored and
will be handled by the normal RX path or by teardown.

However, if usb_submit_urb() fails, the callback unanchors the URB and
then returns directly. This skips the existing free_urb path, so the
coherent transfer buffer allocated with usb_alloc_coherent() is not
released.

Reuse the existing free_urb path after a resubmit failure so that the RX
coherent buffer is freed before leaving the callback.

Fixes: 5eaad4f76826 ("can: usb: etas_es58x: correctly anchor the urb in the read bulk callback")
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
Reviewed-by: Vincent Mailhol <mailhol@xxxxxxxxxx>
---
v3:
  - Regenerate the patch against the correct base so it removes the
  original return statement instead of the v1-added goto.
  - Add the missing changelog. No functional change intended.

v2:
  - Remove the redundant goto and let the error path fall through to
    free_urb, as suggested by Vincent Mailhol.
  - Add Vincent's Reviewed-by tag

 drivers/net/can/usb/etas_es58x/es58x_core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
index b259f6109808..e1724ae79c5a 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_core.c
+++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
@@ -1476,7 +1476,6 @@ static void es58x_read_bulk_callback(struct urb *urb)
 		dev_err_ratelimited(dev,
 				    "Failed resubmitting read bulk urb: %pe\n",
 				    ERR_PTR(ret));
-	return;
 
  free_urb:
 	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
-- 
2.43.0