This is a note to let you know that I've just added the patch titled
i2c: smbus: fix NULL function pointer dereference
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-smbus-fix-null-function-pointer-dereference.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 31a8db6282c3cabd806a2e0b79b676473be76559
Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Date: Fri Apr 26 08:44:08 2024 +0200
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: Baruch Siach <baruch@xxxxxxxxxx>
Closes: https://lore.kernel.org/r/4269631780e5ba789cf1ae391eec1b959def7d99.1712761976.git.baruch@xxxxxxxxxx
Fixes: 4b1acc43331d ("i2c: core changes for slave support")
[wsa: dropped the simplification in core-smbus to avoid theoretical regressions]
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Baruch Siach <baruch@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 964e8a29b27b4..cf9ad03bb34de 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1965,13 +1965,18 @@ 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;
@@ -2038,11 +2043,6 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
int ret;
- if (!adap->algo->master_xfer) {
- dev_dbg(&adap->dev, "I2C level transfers not supported\n");
- return -EOPNOTSUPP;
- }
-
/* REVISIT the fault reporting model here is weak:
*
* - When we get an error after receiving N bytes from a slave,
