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author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2024-04-26 08:44:08 +0200 |
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committer | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2024-04-27 12:57:57 +0200 |
commit | 91811a31b68d3765b3065f4bb6d7d6d84a7cfc9f (patch) | |
tree | 1c93b8e3eed29c8ee9d4ac0cef00f1d8a7f9f275 /drivers/i2c/i2c-core-base.c | |
parent | MAINTAINERS: Drop entry for PCA9541 bus master selector (diff) | |
download | linux-91811a31b68d3765b3065f4bb6d7d6d84a7cfc9f.tar.xz linux-91811a31b68d3765b3065f4bb6d7d6d84a7cfc9f.zip |
i2c: smbus: fix NULL function pointer dereference
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>
Diffstat (limited to '')
-rw-r--r-- | drivers/i2c/i2c-core-base.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index ff5c486a1dbb..db0d1ac82910 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -2200,13 +2200,18 @@ 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; @@ -2273,11 +2278,6 @@ 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, |