5.10-stable review patch. If anyone has any objections, please let me know.
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From: Seungjin Bae eeodqql09@gmail.com
[ 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 --- drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c | 4 ++-- 1 file 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 f06d63db9077b..df0460e3633c5 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; }