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authorWolfram Sang <wsa+renesas@sang-engineering.com>2024-04-26 09:44:08 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-05-02 17:29:32 +0300
commit4e75e222d397c6752b229ed72fc4644c8c36ecde (patch)
tree02603b140be595466b2b4319a05058f2ad674a6e
parent25b3498485ac281e5851700e33b97f12c9533fd8 (diff)
downloadlinux-4e75e222d397c6752b229ed72fc4644c8c36ecde.tar.xz
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 5e3976ba5265..1ebc95379914 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -2075,13 +2075,18 @@ 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;
@@ -2148,11 +2153,6 @@ 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,