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authorSeungjin Bae <eeodqql09@gmail.com>2025-10-23 12:27:09 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-12-07 06:08:22 +0900
commit58343e0a4d43699f0e2f5b169384bbe4c0217add (patch)
tree2f50303433e0b12bcd205f6f03f3273e2358b1d5
parent36bc92b838ff72f62f2c17751a9013b29ead2513 (diff)
can: kvaser_usb: leaf: Fix potential infinite loop in command parsers
[ Upstream commit 0c73772cd2b8cc108d5f5334de89ad648d89b9ec ] The `kvaser_usb_leaf_wait_cmd()` and `kvaser_usb_leaf_read_bulk_callback` functions contain logic to zero-length commands. These commands are used to align data to the USB endpoint's wMaxPacketSize boundary. The driver attempts to skip these placeholders by aligning the buffer position `pos` to the next packet boundary using `round_up()` function. However, if zero-length command is found exactly on a packet boundary (i.e., `pos` is a multiple of wMaxPacketSize, including 0), `round_up` function will return the unchanged value of `pos`. This prevents `pos` to be increased, causing an infinite loop in the parsing logic. This patch fixes this in the function by using `pos + 1` instead. This ensures that even if `pos` is on a boundary, the calculation is based on `pos + 1`, forcing `round_up()` to always return the next aligned boundary. Fixes: 7259124eac7d ("can: kvaser_usb: Split driver into kvaser_usb_core.c and kvaser_usb_leaf.c") Signed-off-by: Seungjin Bae <eeodqql09@gmail.com> Reviewed-by: Jimmy Assarsson <extja@kvaser.com> Tested-by: Jimmy Assarsson <extja@kvaser.com> Link: https://patch.msgid.link/20251023162709.348240-1-eeodqql09@gmail.com Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
index f06d63db9077..df0460e3633c 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -609,7 +609,7 @@ static int kvaser_usb_leaf_wait_cmd(const struct kvaser_usb *dev, u8 id,
* for further details.
*/
if (tmp->len == 0) {
- pos = round_up(pos,
+ pos = round_up(pos + 1,
le16_to_cpu
(dev->bulk_in->wMaxPacketSize));
continue;
@@ -1571,7 +1571,7 @@ static void kvaser_usb_leaf_read_bulk_callback(struct kvaser_usb *dev,
* number of events in case of a heavy rx load on the bus.
*/
if (cmd->len == 0) {
- pos = round_up(pos, le16_to_cpu
+ pos = round_up(pos + 1, le16_to_cpu
(dev->bulk_in->wMaxPacketSize));
continue;
}