Subject: [PATCH] net: ethtool: clear heap allocations for ethtool function

From: Austin Kim <[email-masked]>
Date: Wed, 9 Jun 2021 03:34:25 +0100

Several ethtool functions leave heap uncleared (potentially) by
drivers. This will leave the unused portion of heap unchanged and
might copy the full contents back to userspace.

Signed-off-by: Austin Kim <[email-masked]>
---
 net/ethtool/ioctl.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 3fa7a394eabf..baa5d10043cb 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1421,7 +1421,7 @@ static int ethtool_get_any_eeprom(struct net_device *dev, void __user *useraddr,
 	if (eeprom.offset + eeprom.len > total_len)
 		return -EINVAL;
 
-	data = kmalloc(PAGE_SIZE, GFP_USER);
+	data = kzalloc(PAGE_SIZE, GFP_USER);
 	if (!data)
 		return -ENOMEM;
 
@@ -1486,7 +1486,7 @@ static int ethtool_set_eeprom(struct net_device *dev, void __user *useraddr)
 	if (eeprom.offset + eeprom.len > ops->get_eeprom_len(dev))
 		return -EINVAL;
 
-	data = kmalloc(PAGE_SIZE, GFP_USER);
+	data = kzalloc(PAGE_SIZE, GFP_USER);
 	if (!data)
 		return -ENOMEM;
 
@@ -1765,7 +1765,7 @@ static int ethtool_self_test(struct net_device *dev, char __user *useraddr)
 		return -EFAULT;
 
 	test.len = test_len;
-	data = kmalloc_array(test_len, sizeof(u64), GFP_USER);
+	data = kcalloc(test_len, sizeof(u64), GFP_USER);
 	if (!data)
 		return -ENOMEM;
 
@@ -2293,7 +2293,7 @@ static int ethtool_get_tunable(struct net_device *dev, void __user *useraddr)
 	ret = ethtool_tunable_valid(&tuna);
 	if (ret)
 		return ret;
-	data = kmalloc(tuna.len, GFP_USER);
+	data = kzalloc(tuna.len, GFP_USER);
 	if (!data)
 		return -ENOMEM;
 	ret = ops->get_tunable(dev, &tuna, data);
@@ -2485,7 +2485,7 @@ static int get_phy_tunable(struct net_device *dev, void __user *useraddr)
 	ret = ethtool_phy_tunable_valid(&tuna);
 	if (ret)
 		return ret;
-	data = kmalloc(tuna.len, GFP_USER);
+	data = kzalloc(tuna.len, GFP_USER);
 	if (!data)
 		return -ENOMEM;
 	if (phy_drv_tunable) {
-- 
2.20.1