[PATCH 1/2] regcache: Validate bounds of regcache drop requests

[Mark Brown <broonie@kernel.org>]

It is not valid for a caller to try to drop a range of registers from
the cache where the minimum register is greater than the maximum
register, and doing so is likely to trigger bugs in the caches.  Reject
such invalid inputs.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/base/regmap/regcache.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 774e9c9bf3c4..1447967ff00b 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -589,6 +589,9 @@ int regcache_drop_region(struct regmap *map, unsigned int min,
 
 	trace_regcache_drop_region(map, min, max);
 
+	if (min > max)
+		return -EINVAL;
+
 	return map->cache_ops->drop(map, min, max);
 }
 EXPORT_SYMBOL_GPL(regcache_drop_region);

-- 
2.47.3