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authorWolfram Sang <wsa+renesas@sang-engineering.com>2024-04-26 08:44:08 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-05-02 16:32:49 +0200
commite3425674ff68dc521c57c6eabad0cbd20a027d85 (patch)
tree6b3ce75259440e9e97a1ac3b87a481fb95d5a66a
parent470d347b14b0ecffa9b39cf8f644fa2351db3efb (diff)
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@tkos.co.il> Closes: https://lore.kernel.org/r/4269631780e5ba789cf1ae391eec1b959def7d99.1712761976.git.baruch@tkos.co.il 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@sang-engineering.com> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/i2c/i2c-core-base.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 7f30bcceebae..3642d4246320 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -2187,13 +2187,18 @@ 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;
@@ -2260,11 +2265,6 @@ 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,