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Commit 40f1d79f authored by Wolfram Sang's avatar Wolfram Sang Committed by Greg Kroah-Hartman
Browse files

i2c: smbus: fix NULL function pointer dereference 



[ Upstream commit 91811a31b68d3765b3065f4bb6d7d6d84a7cfc9f ]

Baruch reported an OOPS when using the designware controller as target
only. Target-only modes break the assumption of one transfer function
always being available. Fix this by always checking the pointer in
__i2c_transfer.

Reported-by: default avatarBaruch Siach <baruch@tkos.co.il>
Closes: https://lore.kernel.org/r/4269631780e5ba789cf1ae391eec1b959def7d99.1712761976.git.baruch@tkos.co.il


Fixes: 4b1acc43 ("i2c: core changes for slave support")
[wsa: dropped the simplification in core-smbus to avoid theoretical regressions]
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: default avatarBaruch Siach <baruch@tkos.co.il>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent ffe3f362

drivers/i2c/i2c-core-base.c

+6 −1
Original line number Diff line number Diff line
@@ -1872,13 +1872,18 @@ static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, 
 * Returns negative errno, else the number of messages executed.

 *

 * Adapter lock must be held when calling this function. No debug logging

 * takes place. adap->algo->master_xfer existence isn't checked.

 * takes place.

 */

int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)

{

	unsigned long orig_jiffies;

	int ret, try;



	if (!adap->algo->master_xfer) {

		dev_dbg(&adap->dev, "I2C level transfers not supported\n");

		return -EOPNOTSUPP;

	}



	if (WARN_ON(!msgs || num < 1))

		return -EINVAL;