| Message ID | 20220704122613.1551119-15-mkl@pengutronix.de (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 0ff32bfa0e794ccc3601de7158b522bf736fa63c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,01/15] can: bcm: use call_rcu() instead of costly synchronize_rcu() | expand |
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);
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> --- drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)