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authorLi RongQing <lirongqing@baidu.com>2019-03-29 09:18:02 +0800
committerDavid S. Miller <davem@davemloft.net>2019-03-29 13:41:55 -0700
commit3d8830266ffc28c16032b859e38a0252e014b631 (patch)
treec09e7bdb15135334481111a1ea485d07cada840c /net/core
parentc43ac97bac987e56c179598ce3398a95d55067bc (diff)
downloadlinux-3d8830266ffc28c16032b859e38a0252e014b631.tar.bz2
net: ethtool: not call vzalloc for zero sized memory request
NULL or ZERO_SIZE_PTR will be returned for zero sized memory request, and derefencing them will lead to a segfault so it is unnecessory to call vzalloc for zero sized memory request and not call functions which maybe derefence the NULL allocated memory this also fixes a possible memory leak if phy_ethtool_get_stats returns error, memory should be freed before exit Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Wang Li <wangli39@baidu.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/ethtool.c46
1 files changed, 30 insertions, 16 deletions
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index b1eb32419732..36ed619faf36 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1797,11 +1797,16 @@ static int ethtool_get_strings(struct net_device *dev, void __user *useraddr)
WARN_ON_ONCE(!ret);
gstrings.len = ret;
- data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN));
- if (gstrings.len && !data)
- return -ENOMEM;
- __ethtool_get_strings(dev, gstrings.string_set, data);
+ if (gstrings.len) {
+ data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN));
+ if (!data)
+ return -ENOMEM;
+
+ __ethtool_get_strings(dev, gstrings.string_set, data);
+ } else {
+ data = NULL;
+ }
ret = -EFAULT;
if (copy_to_user(useraddr, &gstrings, sizeof(gstrings)))
@@ -1897,11 +1902,15 @@ static int ethtool_get_stats(struct net_device *dev, void __user *useraddr)
return -EFAULT;
stats.n_stats = n_stats;
- data = vzalloc(array_size(n_stats, sizeof(u64)));
- if (n_stats && !data)
- return -ENOMEM;
- ops->get_ethtool_stats(dev, &stats, data);
+ if (n_stats) {
+ data = vzalloc(array_size(n_stats, sizeof(u64)));
+ if (!data)
+ return -ENOMEM;
+ ops->get_ethtool_stats(dev, &stats, data);
+ } else {
+ data = NULL;
+ }
ret = -EFAULT;
if (copy_to_user(useraddr, &stats, sizeof(stats)))
@@ -1941,16 +1950,21 @@ static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr)
return -EFAULT;
stats.n_stats = n_stats;
- data = vzalloc(array_size(n_stats, sizeof(u64)));
- if (n_stats && !data)
- return -ENOMEM;
- if (dev->phydev && !ops->get_ethtool_phy_stats) {
- ret = phy_ethtool_get_stats(dev->phydev, &stats, data);
- if (ret < 0)
- return ret;
+ if (n_stats) {
+ data = vzalloc(array_size(n_stats, sizeof(u64)));
+ if (!data)
+ return -ENOMEM;
+
+ if (dev->phydev && !ops->get_ethtool_phy_stats) {
+ ret = phy_ethtool_get_stats(dev->phydev, &stats, data);
+ if (ret < 0)
+ goto out;
+ } else {
+ ops->get_ethtool_phy_stats(dev, &stats, data);
+ }
} else {
- ops->get_ethtool_phy_stats(dev, &stats, data);
+ data = NULL;
}
ret = -EFAULT;