[PATCH 5.4 11/43] s390/ctcm: fix variable dereferenced before check

Greg Kroah-Hartman
2022-05-16T19:43:45Z

From: Alexandra Winter <wintera@linux.ibm.com>

[ Upstream commit 2c50c6867c85afee6f2b3bcbc50fc9d0083d1343 ]

Found by cppcheck and smatch.
smatch complains about
drivers/s390/net/ctcm_sysfs.c:43 ctcm_buffer_write() warn: variable dereferenced before check 'priv' (see line 42)

Fixes: 3c09e2647b5e ("ctcm: rename READ/WRITE defines to avoid redefinitions")
Reported-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/s390/net/ctcm_sysfs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/net/ctcm_sysfs.c b/drivers/s390/net/ctcm_sysfs.c
index ded1930a00b2..e3813a7aa5e6 100644
--- a/drivers/s390/net/ctcm_sysfs.c
+++ b/drivers/s390/net/ctcm_sysfs.c
@@ -39,11 +39,12 @@ static ssize_t ctcm_buffer_write(struct device *dev,
struct ctcm_priv *priv = dev_get_drvdata(dev);
int rc;

- ndev = priv->channel[CTCM_READ]->netdev;
- if (!(priv && priv->channel[CTCM_READ] && ndev)) {
+ if (!(priv && priv->channel[CTCM_READ] &&
+ priv->channel[CTCM_READ]->netdev)) {
CTCM_DBF_TEXT(SETUP, CTC_DBF_ERROR, "bfnondev");
return -ENODEV;
}
+ ndev = priv->channel[CTCM_READ]->netdev;

rc = kstrtouint(buf, 0, &bs1);
if (rc)
--
2.35.1