[PATCH][next] media: ispstat: don't dereference user_cfg before a null check

From: Colin King
Date: Tue Apr 24 2018 - 09:06:42 EST

From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The pointer user_cfg (a copy of new_conf) is dereference before
new_conf is null checked, hence we may have a null pointer dereference
on user_cfg when assigning buf_size from user_cfg->buf_size. Ensure
this does not occur by moving the assignment of buf_size after the
null check.

Detected by CoverityScan, CID#1468386 ("Dereference before null check")

Fixes: 68e342b3068c ("[media] omap3isp: Statistics")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
drivers/media/platform/omap3isp/ispstat.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/omap3isp/ispstat.c b/drivers/media/platform/omap3isp/ispstat.c
index 0b31f6c5791f..38cb1b2cc672 100644
--- a/drivers/media/platform/omap3isp/ispstat.c
+++ b/drivers/media/platform/omap3isp/ispstat.c
@@ -523,7 +523,7 @@ int omap3isp_stat_config(struct ispstat *stat, void *new_conf)
int ret;
unsigned long irqflags;
struct ispstat_generic_config *user_cfg = new_conf;
- u32 buf_size = user_cfg->buf_size;
+ u32 buf_size;

if (!new_conf) {
dev_dbg(stat->isp->dev, "%s: configuration is NULL\n",
@@ -532,6 +532,7 @@ int omap3isp_stat_config(struct ispstat *stat, void *new_conf)

+ buf_size = user_cfg->buf_size;

"%s: configuring module with buffer size=0x%08lx\n",