| From 2ea811d475d262baa361683ae4df8da30e5bcf77 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 26 Apr 2024 08:44:08 +0200 |
| Subject: i2c: smbus: fix NULL function pointer dereference |
| |
| From: Wolfram Sang <wsa+renesas@sang-engineering.com> |
| |
| [ 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> |
| --- |
| drivers/i2c/i2c-core-base.c | 7 ++++++- |
| 1 file changed, 6 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c |
| index 9079be0d51d15..2bdb8bc4cc829 100644 |
| --- a/drivers/i2c/i2c-core-base.c |
| +++ b/drivers/i2c/i2c-core-base.c |
| @@ -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; |
| |
| -- |
| 2.43.0 |
| |
