This is a note to let you know that I've just added the patch titled can: esd_usb2: fix memory leak to the 4.14-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-esd_usb2-fix-memory-leak.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 928150fad41ba16df7fcc9f7f945747d0f56cbb6 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin <paskripkin@xxxxxxxxx> Date: Tue, 27 Jul 2021 20:00:46 +0300 Subject: can: esd_usb2: fix memory leak From: Pavel Skripkin <paskripkin@xxxxxxxxx> commit 928150fad41ba16df7fcc9f7f945747d0f56cbb6 upstream. In esd_usb2_setup_rx_urbs() 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 esd_usb2_setup_rx_urbs) 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: 96d8e90382dc ("can: Add driver for esd CAN-USB/2 device") Link: https://lore.kernel.org/r/b31b096926dcb35998ad0271aac4b51770ca7cc8.1627404470.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/esd_usb2.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) --- a/drivers/net/can/usb/esd_usb2.c +++ b/drivers/net/can/usb/esd_usb2.c @@ -207,6 +207,8 @@ struct esd_usb2 { int net_count; u32 version; int rxinitdone; + void *rxbuf[MAX_RX_URBS]; + dma_addr_t rxbuf_dma[MAX_RX_URBS]; }; struct esd_usb2_net_priv { @@ -556,6 +558,7 @@ static int esd_usb2_setup_rx_urbs(struct 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); @@ -565,7 +568,7 @@ static int esd_usb2_setup_rx_urbs(struct } buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, - &urb->transfer_dma); + &buf_dma); if (!buf) { dev_warn(dev->udev->dev.parent, "No memory left for USB buffer\n"); @@ -573,6 +576,8 @@ static int esd_usb2_setup_rx_urbs(struct goto freeurb; } + urb->transfer_dma = buf_dma; + usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1), buf, RX_BUFFER_SIZE, @@ -585,8 +590,12 @@ static int esd_usb2_setup_rx_urbs(struct usb_unanchor_urb(urb); usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, urb->transfer_dma); + goto freeurb; } + dev->rxbuf[i] = buf; + dev->rxbuf_dma[i] = buf_dma; + freeurb: /* Drop reference, USB core will take care of freeing it */ usb_free_urb(urb); @@ -674,6 +683,11 @@ static void unlink_all_urbs(struct esd_u int i, j; 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]); + for (i = 0; i < dev->net_count; i++) { priv = dev->nets[i]; if (priv) { Patches currently in stable-queue which might be from paskripkin@xxxxxxxxx are queue-4.14/can-usb_8dev-fix-memory-leak.patch queue-4.14/can-ems_usb-fix-memory-leak.patch queue-4.14/workqueue-fix-uaf-in-pwq_unbound_release_workfn.patch queue-4.14/can-esd_usb2-fix-memory-leak.patch queue-4.14/can-mcba_usb_start-add-missing-urb-transfer_dma-initialization.patch