[PATCH] misc: vexpress: Off by one in vexpress_syscfg_exec()

[PATCH] misc: vexpress: Off by one in vexpress_syscfg_exec()

[Dan Carpenter]

The > comparison should be >= to prevent reading beyond the end of the
func->template[] array.

(The func->template array is allocated in vexpress_syscfg_regmap_init()
and it has func->num_templates elements.)

Fixes: 974cc7b93441 ("mfd: vexpress: Define the device as MFD cells")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/misc/vexpress-syscfg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c
index 6c3591cdf855..a3c6c773d9dc 100644
--- a/drivers/misc/vexpress-syscfg.c
+++ b/drivers/misc/vexpress-syscfg.c
@@ -61,7 +61,7 @@ static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
 	int tries;
 	long timeout;
 
-	if (WARN_ON(index > func->num_templates))
+	if (WARN_ON(index >= func->num_templates))
 		return -EINVAL;
 
 	command = readl(syscfg->base + SYS_CFGCTRL);
-- 
2.11.0

Re: [PATCH] misc: vexpress: Off by one in vexpress_syscfg_exec()

[Sudeep Holla]

On Mon, Dec 03, 2018 at 05:52:19PM +0300, Dan Carpenter wrote:
> The > comparison should be >= to prevent reading beyond the end of the
> func->template[] array.
> 
> (The func->template array is allocated in vexpress_syscfg_regmap_init()
> and it has func->num_templates elements.)
> 
> Fixes: 974cc7b93441 ("mfd: vexpress: Define the device as MFD cells")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Good catch, thanks for identifying and fixing this.

Acked-by: Sudeep Holla <sudeep.holla@arm.com>

I assume Greg will pick this up, if not I will add this when I send
pull request next time(not sure when yet as I don't have anything for
v4.21)

--
Regards,
Sudeep