platform/chrome: cros_ec_spi: drop BUG_ON() if `din` isn't large enough

It is overkill to crash the kernel if the `din` buffer is going to full
or overflow.

Drop the BUG_ON() and return -EINVAL instead.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20220513044143.1045728-8-tzungbi@kernel.org

diff --git a/drivers/platform/chrome/cros_ec_spi.c b/drivers/platform/chrome/cros_ec_spi.c
index 5264615f46aff1d6dc559cca49fd5060b78d590c..7360b3ff6e4fc8f5f48821aa15c9b99a48947f14 100644 (file)
--- a/drivers/platform/chrome/cros_ec_spi.c
+++ b/drivers/platform/chrome/cros_ec_spi.c
@@ -160,7 +160,8 @@ static int receive_n_bytes(struct cros_ec_device *ec_dev, u8 *buf, int n)
        struct spi_message msg;
        int ret;
 
-       BUG_ON(buf - ec_dev->din + n > ec_dev->din_size);
+       if (buf - ec_dev->din + n > ec_dev->din_size)
+               return -EINVAL;
 
        memset(&trans, 0, sizeof(trans));
        trans.cs_change = 1;
@@ -197,7 +198,8 @@ static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,
        unsigned long deadline;
        int todo;
 
-       BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
+       if (ec_dev->din_size < EC_MSG_PREAMBLE_COUNT)
+               return -EINVAL;
 
        /* Receive data until we see the header byte */
        deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
@@ -304,7 +306,8 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
        unsigned long deadline;
        int todo;
 
-       BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
+       if (ec_dev->din_size < EC_MSG_PREAMBLE_COUNT)
+               return -EINVAL;
 
        /* Receive data until we see the header byte */
        deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);