[PATCH v2 3/3] can: esd_usb2: fix memory leak
From: Pavel Skripkin <hidden>
Date: 2021-07-27 17:00:57
Also in:
linux-can, lkml
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
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")
Signed-off-by: Pavel Skripkin <redacted>
---
drivers/net/can/usb/esd_usb2.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/usb/esd_usb2.c b/drivers/net/can/usb/esd_usb2.c
index 65b58f8fc328..66fa8b07c2e6 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/drivers/net/can/usb/esd_usb2.c@@ -195,6 +195,8 @@ 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 {
@@ -545,6 +547,7 @@ static int esd_usb2_setup_rx_urbs(struct esd_usb2 *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);
@@ -554,7 +557,7 @@ static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev) } 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");
@@ -562,6 +565,8 @@ static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev) goto freeurb; } + urb->transfer_dma = buf_dma; + usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 1), buf, RX_BUFFER_SIZE,
@@ -574,8 +579,12 @@ static int esd_usb2_setup_rx_urbs(struct esd_usb2 *dev) 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);
@@ -663,6 +672,11 @@ static void unlink_all_urbs(struct esd_usb2 *dev) 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) {
--
2.32.0