The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0ff32bfa0e794ccc3601de7158b522bf736fa63c Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde mkl@pengutronix.de Date: Thu, 16 Jun 2022 11:38:00 +0200 Subject: [PATCH] can: mcp251xfd: mcp251xfd_register_get_dev_id(): use correct length to read dev_id
The device ID register is 32 bits wide. The driver uses incorrectly the size of a pointer to a u32 to calculate the length of the SPI transfer. This results in a read of 2 registers on 64 bit platforms. This is no problem on the Linux side, as the RX buffer of the SPI transfer is large enough. In the mpc251xfd chip this results in the read of an undocumented register. So far no problems were observed.
Fix the length of the SPI transfer to read the device ID register only.
Link: https://lore.kernel.org/all/20220616094914.244440-1-mkl@pengutronix.de Fixes: 55e5b97f003e ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN") Reported-by: Rasmus Villemoes rasmus.villemoes@prevas.dk Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 34b160024ce3..3160881e89d9 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -1778,7 +1778,7 @@ mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id, xfer[0].len = sizeof(buf_tx->cmd); xfer[0].speed_hz = priv->spi_max_speed_hz_slow; xfer[1].rx_buf = buf_rx->data; - xfer[1].len = sizeof(dev_id); + xfer[1].len = sizeof(*dev_id); xfer[1].speed_hz = priv->spi_max_speed_hz_fast;
mcp251xfd_spi_cmd_read_nocrc(&buf_tx->cmd, MCP251XFD_REG_DEVID);