From: Pavel Skripkin paskripkin@gmail.com
stable inclusion from stable-5.10.56 commit 88b40258162b277016bbec2a9679418c223dca25 bugzilla: 176004 https://gitee.com/openeuler/kernel/issues/I4DYZ4
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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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: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@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 db9f15f17610..249d2fba28c7 100644 --- 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 *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); @@ -596,7 +599,7 @@ 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); @@ -604,6 +607,8 @@ 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); @@ -619,6 +624,9 @@ 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); } @@ -684,6 +692,10 @@ 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);