[PATCH 4.4 34/97] regmap: Fix reversed bounds check in regmap_raw_write()

From: Greg Kroah-Hartman
Date: Sun Apr 22 2018 - 10:17:40 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit f00e71091ab92eba52122332586c6ecaa9cd1a56 upstream.

We're supposed to be checking that "val_len" is not too large but
instead we check if it is smaller than the max.

The only function affected would be regmap_i2c_smbus_i2c_write() in
drivers/base/regmap/regmap-i2c.c. Strangely that function has its own
limit check which returns an error if (count >= I2C_SMBUS_BLOCK_MAX) so
it doesn't look like it has ever been able to do anything except return
an error.

Fixes: c335931ed9d2 ("regmap: Add raw_write/read checks for max_raw_write/read sizes")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/base/regmap/regmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1582,7 +1582,7 @@ int regmap_raw_write(struct regmap *map,
return -EINVAL;
if (val_len % map->format.val_bytes)
return -EINVAL;
- if (map->max_raw_write && map->max_raw_write > val_len)
+ if (map->max_raw_write && map->max_raw_write < val_len)
return -E2BIG;

map->lock(map->lock_arg);