diff options
| author | Li RongQing <lirongqing@baidu.com> | 2019-03-29 09:18:02 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-17 08:37:50 +0200 |
| commit | eea06f38eb464ab6ebdc04ca5980120dd24ee48d (patch) | |
| tree | 38772296da3c3444531d97830780ff7620903d80 /net/core | |
| parent | adbb8bdd392db14dc80ad1ac29f8f1d37ab57a62 (diff) | |
net: ethtool: not call vzalloc for zero sized memory request
[ Upstream commit 3d8830266ffc28c16032b859e38a0252e014b631 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/ethtool.c | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 3469f5053c79..145cb343c1b0 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -1815,11 +1815,15 @@ static int ethtool_get_strings(struct net_device *dev, void __user *useraddr) WARN_ON_ONCE(!ret); gstrings.len = ret; - data = vzalloc(gstrings.len * ETH_GSTRING_LEN); - if (gstrings.len && !data) - return -ENOMEM; + if (gstrings.len) { + data = vzalloc(gstrings.len * ETH_GSTRING_LEN); + if (!data) + return -ENOMEM; - __ethtool_get_strings(dev, gstrings.string_set, data); + __ethtool_get_strings(dev, gstrings.string_set, data); + } else { + data = NULL; + } ret = -EFAULT; if (copy_to_user(useraddr, &gstrings, sizeof(gstrings))) @@ -1915,11 +1919,14 @@ static int ethtool_get_stats(struct net_device *dev, void __user *useraddr) return -EFAULT; stats.n_stats = n_stats; - data = vzalloc(n_stats * sizeof(u64)); - if (n_stats && !data) - return -ENOMEM; - - ops->get_ethtool_stats(dev, &stats, data); + if (n_stats) { + data = vzalloc(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))) @@ -1955,13 +1962,17 @@ static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr) return -EFAULT; stats.n_stats = n_stats; - data = vzalloc(n_stats * sizeof(u64)); - if (n_stats && !data) - return -ENOMEM; + if (n_stats) { + data = vzalloc(n_stats * sizeof(u64)); + if (!data) + return -ENOMEM; - mutex_lock(&phydev->lock); - phydev->drv->get_stats(phydev, &stats, data); - mutex_unlock(&phydev->lock); + mutex_lock(&phydev->lock); + phydev->drv->get_stats(phydev, &stats, data); + mutex_unlock(&phydev->lock); + } else { + data = NULL; + } ret = -EFAULT; if (copy_to_user(useraddr, &stats, sizeof(stats))) |