| From 9969e3c5f40c166e3396acc36c34f9de502929f6 Mon Sep 17 00:00:00 2001 |
| From: Pavel Skripkin <paskripkin@gmail.com> |
| Date: Tue, 27 Jul 2021 20:00:33 +0300 |
| Subject: can: ems_usb: fix memory leak |
| |
| From: Pavel Skripkin <paskripkin@gmail.com> |
| |
| commit 9969e3c5f40c166e3396acc36c34f9de502929f6 upstream. |
| |
| In ems_usb_start() MAX_RX_URBS coherent buffers are allocated and |
| there is nothing, that frees them: |
| |
| 1) In callback function the urb is resubmitted and that's all |
| 2) In disconnect function urbs are simply killed, but URB_FREE_BUFFER |
| is not set (see ems_usb_start) and this flag cannot be used with |
| coherent buffers. |
| |
| So, all allocated buffers should be freed with usb_free_coherent() |
| explicitly. |
| |
| Side note: This code looks like a copy-paste of other can drivers. The |
| same patch was applied to mcba_usb driver and it works nice with real |
| hardware. There is no change in functionality, only clean-up code for |
| coherent buffers. |
| |
| Fixes: 702171adeed3 ("ems_usb: Added support for EMS CPC-USB/ARM7 CAN/USB interface") |
| Link: https://lore.kernel.org/r/59aa9fbc9a8cbf9af2bbd2f61a659c480b415800.1627404470.git.paskripkin@gmail.com |
| Cc: linux-stable <stable@vger.kernel.org> |
| Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> |
| Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/can/usb/ems_usb.c | 14 +++++++++++++- |
| 1 file changed, 13 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/net/can/usb/ems_usb.c |
| +++ b/drivers/net/can/usb/ems_usb.c |
| @@ -255,6 +255,8 @@ struct ems_usb { |
| unsigned int free_slots; /* remember number of available slots */ |
| |
| struct ems_cpc_msg active_params; /* active controller parameters */ |
| + void *rxbuf[MAX_RX_URBS]; |
| + dma_addr_t rxbuf_dma[MAX_RX_URBS]; |
| }; |
| |
| static void ems_usb_read_interrupt_callback(struct urb *urb) |
| @@ -587,6 +589,7 @@ static int ems_usb_start(struct ems_usb |
| for (i = 0; i < MAX_RX_URBS; i++) { |
| struct urb *urb = NULL; |
| u8 *buf = NULL; |
| + dma_addr_t buf_dma; |
| |
| /* create a URB, and a buffer for it */ |
| urb = usb_alloc_urb(0, GFP_KERNEL); |
| @@ -596,7 +599,7 @@ static int ems_usb_start(struct ems_usb |
| } |
| |
| buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, |
| - &urb->transfer_dma); |
| + &buf_dma); |
| if (!buf) { |
| netdev_err(netdev, "No memory left for USB buffer\n"); |
| usb_free_urb(urb); |
| @@ -604,6 +607,8 @@ static int ems_usb_start(struct ems_usb |
| break; |
| } |
| |
| + urb->transfer_dma = buf_dma; |
| + |
| usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), |
| buf, RX_BUFFER_SIZE, |
| ems_usb_read_bulk_callback, dev); |
| @@ -619,6 +624,9 @@ static int ems_usb_start(struct ems_usb |
| break; |
| } |
| |
| + dev->rxbuf[i] = buf; |
| + dev->rxbuf_dma[i] = buf_dma; |
| + |
| /* Drop reference, USB core will take care of freeing it */ |
| usb_free_urb(urb); |
| } |
| @@ -684,6 +692,10 @@ static void unlink_all_urbs(struct ems_u |
| |
| usb_kill_anchored_urbs(&dev->rx_submitted); |
| |
| + for (i = 0; i < MAX_RX_URBS; ++i) |
| + usb_free_coherent(dev->udev, RX_BUFFER_SIZE, |
| + dev->rxbuf[i], dev->rxbuf_dma[i]); |
| + |
| usb_kill_anchored_urbs(&dev->tx_submitted); |
| atomic_set(&dev->active_tx_urbs, 0); |
| |