This is a note to let you know that I've just added the patch titled can: usb_8dev: fix memory leak to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: can-usb_8dev-fix-memory-leak.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0e865f0c31928d6a313269ef624907eec55287c4 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin <paskripkin@xxxxxxxxx> Date: Tue, 27 Jul 2021 19:59:57 +0300 Subject: can: usb_8dev: fix memory leak From: Pavel Skripkin <paskripkin@xxxxxxxxx> commit 0e865f0c31928d6a313269ef624907eec55287c4 upstream. In usb_8dev_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 usb_8dev_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: 0024d8ad1639 ("can: usb_8dev: Add support for USB2CAN interface from 8 devices") Link: https://lore.kernel.org/r/d39b458cd425a1cf7f512f340224e6e9563b07bd.1627404470.git.paskripkin@xxxxxxxxx Cc: linux-stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/can/usb/usb_8dev.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/net/can/usb/usb_8dev.c +++ b/drivers/net/can/usb/usb_8dev.c @@ -148,7 +148,8 @@ struct usb_8dev_priv { u8 *cmd_msg_buffer; struct mutex usb_8dev_cmd_lock; - + void *rxbuf[MAX_RX_URBS]; + dma_addr_t rxbuf_dma[MAX_RX_URBS]; }; /* tx frame */ @@ -744,6 +745,7 @@ static int usb_8dev_start(struct usb_8de for (i = 0; i < MAX_RX_URBS; i++) { struct urb *urb = NULL; u8 *buf; + dma_addr_t buf_dma; /* create a URB, and a buffer for it */ urb = usb_alloc_urb(0, GFP_KERNEL); @@ -753,7 +755,7 @@ static int usb_8dev_start(struct usb_8de } buf = usb_alloc_coherent(priv->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); @@ -761,6 +763,8 @@ static int usb_8dev_start(struct usb_8de break; } + urb->transfer_dma = buf_dma; + usb_fill_bulk_urb(urb, priv->udev, usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX), @@ -778,6 +782,9 @@ static int usb_8dev_start(struct usb_8de break; } + priv->rxbuf[i] = buf; + priv->rxbuf_dma[i] = buf_dma; + /* Drop reference, USB core will take care of freeing it */ usb_free_urb(urb); } @@ -847,6 +854,10 @@ static void unlink_all_urbs(struct usb_8 usb_kill_anchored_urbs(&priv->rx_submitted); + for (i = 0; i < MAX_RX_URBS; ++i) + usb_free_coherent(priv->udev, RX_BUFFER_SIZE, + priv->rxbuf[i], priv->rxbuf_dma[i]); + usb_kill_anchored_urbs(&priv->tx_submitted); atomic_set(&priv->active_tx_urbs, 0); Patches currently in stable-queue which might be from paskripkin@xxxxxxxxx are queue-4.19/can-usb_8dev-fix-memory-leak.patch queue-4.19/can-ems_usb-fix-memory-leak.patch queue-4.19/can-esd_usb2-fix-memory-leak.patch queue-4.19/can-mcba_usb_start-add-missing-urb-transfer_dma-initialization.patch