[PATCH] regmap: cache: Add extra parameter check in regcache_init

[PATCH] regmap: cache: Add extra parameter check in regcache_init

[Schspa Shi]

When num_reg_defaults > 0 but reg_defaults is NULL, there will be a
NULL pointer exception.

Current code has no such usage, but as additional hardening, also
check this to prevent any chance of crashing.

Signed-off-by: Schspa Shi <schspa@gmail.com>
---
 drivers/base/regmap/regcache.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index d0f5bc827978..d8c31c8ac4a0 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -133,6 +133,12 @@ int regcache_init(struct regmap *map, const struct regmap_config *config)
 		return -EINVAL;
 	}
 
+	if (config->num_reg_defaults && !config->reg_defaults) {
+		dev_err(map->dev,
+			"Register defaults number are set without the reg!\n");
+		return -EINVAL;
+	}
+
 	for (i = 0; i < config->num_reg_defaults; i++)
 		if (config->reg_defaults[i].reg % map->reg_stride)
 			return -EINVAL;
-- 
2.29.0

Re: [PATCH] regmap: cache: Add extra parameter check in regcache_init

[Mark Brown]

On Wed, 29 Jun 2022 21:09:51 +0800, Schspa Shi wrote:
> When num_reg_defaults > 0 but reg_defaults is NULL, there will be a
> NULL pointer exception.
> 
> Current code has no such usage, but as additional hardening, also
> check this to prevent any chance of crashing.
> 
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

Thanks!

[1/1] regmap: cache: Add extra parameter check in regcache_init
      commit: a5201d42e2f8a8e8062103170027840ee372742f

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark