From: Pavel Skripkin paskripkin@gmail.com
stable inclusion from linux-4.19.201 commit 71758cd0f1b09e8cd7c22059301018ffb0696778
--------------------------------
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/59aa9fbc9a8cbf9af2bbd2f61a659c480b415800.162740447... 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 Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/net/can/usb/ems_usb.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c index 16b96f978aae7..3957b746107f1 100644 --- a/drivers/net/can/usb/ems_usb.c +++ b/drivers/net/can/usb/ems_usb.c @@ -267,6 +267,8 @@ 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) @@ -599,6 +601,7 @@ static int ems_usb_start(struct ems_usb *dev) 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); @@ -608,7 +611,7 @@ static int ems_usb_start(struct ems_usb *dev) }
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); @@ -616,6 +619,8 @@ static int ems_usb_start(struct ems_usb *dev) 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); @@ -631,6 +636,9 @@ static int ems_usb_start(struct ems_usb *dev) 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); } @@ -696,6 +704,10 @@ static void unlink_all_urbs(struct ems_usb *dev)
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);