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 08:36:46 +0200 |
| commit | 77b924d94dd7a7719933ba9d97a7ba4d19d09d00 (patch) | |
| tree | 0ff3e75ea71fc49be102398996f2da872f89eca1 /net/core | |
| parent | 6996763856e1fb27ccae260e41fd73a3fff56678 (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 | 47 |
1 files changed, 30 insertions, 17 deletions
diff --git a/net/core/ethtool.c b/net/core/ethtool.c index a8a9938aeceb..20ae57fbe009 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -1801,17 +1801,22 @@ static int ethtool_get_strings(struct net_device *dev, void __user *useraddr) gstrings.len = ret; - data = kcalloc(gstrings.len, ETH_GSTRING_LEN, GFP_USER); - if (!data) - return -ENOMEM; + if (gstrings.len) { + data = kcalloc(gstrings.len, ETH_GSTRING_LEN, GFP_USER); + 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))) goto out; useraddr += sizeof(gstrings); - if (copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN)) + if (gstrings.len && + copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN)) goto out; ret = 0; @@ -1899,17 +1904,21 @@ static int ethtool_get_stats(struct net_device *dev, void __user *useraddr) return -EFAULT; stats.n_stats = n_stats; - data = kmalloc(n_stats * sizeof(u64), GFP_USER); - if (!data) - return -ENOMEM; + if (n_stats) { + data = kmalloc(n_stats * sizeof(u64), GFP_USER); + if (!data) + return -ENOMEM; - ops->get_ethtool_stats(dev, &stats, data); + ops->get_ethtool_stats(dev, &stats, data); + } else { + data = NULL; + } ret = -EFAULT; if (copy_to_user(useraddr, &stats, sizeof(stats))) goto out; useraddr += sizeof(stats); - if (copy_to_user(useraddr, data, stats.n_stats * sizeof(u64))) + if (n_stats && copy_to_user(useraddr, data, n_stats * sizeof(u64))) goto out; ret = 0; @@ -1938,19 +1947,23 @@ static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr) return -EFAULT; stats.n_stats = n_stats; - data = kmalloc_array(n_stats, sizeof(u64), GFP_USER); - if (!data) - return -ENOMEM; + if (n_stats) { + data = kmalloc_array(n_stats, sizeof(u64), GFP_USER); + 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))) goto out; useraddr += sizeof(stats); - if (copy_to_user(useraddr, data, stats.n_stats * sizeof(u64))) + if (n_stats && copy_to_user(useraddr, data, n_stats * sizeof(u64))) goto out; ret = 0; |