[PATCH v7 3/4] i2c: add param sanity check to i2c_transfer()

[ard.biesheuvel@linaro.org (Ard Biesheuvel)]

The API docs describe i2c_transfer() as taking a pointer to an array
of i2c_msg containing at least 1 entry, but leaves it to the individual
drivers to sanity check the msgs and num parameters. Let's do this in
core code instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 drivers/i2c/i2c-core-base.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index c8bfe008f208..e2ca5c331ecb 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1845,6 +1845,9 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	unsigned long orig_jiffies;
 	int ret, try;
 
+	if (WARN_ON(!msgs || num <= 0))
+		return -EINVAL;
+
 	if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
 		return -EOPNOTSUPP;
 
-- 
2.15.1