2015-08-31 17:17:32

by Sylvain Rochet

Subject: [PATCH] regmap: fix NULL pointer dereference in __regmap_init if bus is NULL

This fix adds a check for bus pointer before using bus struct members.

Signed-off-by: Sylvain Rochet <[email protected]>
---
drivers/base/regmap/regmap.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

It was introduced by https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=5e5a40ab02e497fd234a54c3fb6eb05286636e7a
but I failed to find the commit which is not the merge commit.

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 650d3b1..7797cfd 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -574,8 +574,10 @@ struct regmap *__regmap_init(struct device *dev,
map->use_single_read = config->use_single_rw || !bus || !bus->read;
map->use_single_write = config->use_single_rw || !bus || !bus->write;
map->can_multi_write = config->can_multi_write && bus && bus->write;
- map->max_raw_read = bus->max_raw_read;
- map->max_raw_write = bus->max_raw_write;
+ if (bus) {
+ map->max_raw_read = bus->max_raw_read;
+ map->max_raw_write = bus->max_raw_write;
+ }
map->dev = dev;
map->bus = bus;
map->bus_context = bus_context;
--
2.5.1

2015-08-31 17:29:40

by Sylvain Rochet

Subject: Re: [PATCH] regmap: fix NULL pointer dereference in __regmap_init if bus is NULL

Hello,

On Mon, Aug 31, 2015 at 07:17:09PM +0200, Sylvain Rochet wrote:
> This fix adds a check for bus pointer before using bus struct members.

I just found out I'm a little too late, Sergey sent the exact same patch
a few hours ago, dammit :-)

Sylvain