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Commit 5393b917 authored by Johannes Berg's avatar Johannes Berg
Browse files

cfg80211: clear nl80211 messages carrying keys after processing 



Clear any nl80211 messages that might contain keys after
processing them to avoid leaving their data in memory
"forever" after they've been freed.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 78f686ca

net/wireless/nl80211.c

+21 −4
Original line number Diff line number Diff line
@@ -9400,6 +9400,7 @@ static int nl80211_set_qos_map(struct sk_buff *skb, 
/* If a netdev is associated, it must be UP, P2P must be started */

#define NL80211_FLAG_NEED_WDEV_UP	(NL80211_FLAG_NEED_WDEV |\

					 NL80211_FLAG_CHECK_NETDEV_UP)

#define NL80211_FLAG_CLEAR_SKB		0x20



static int nl80211_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,

			    struct genl_info *info)
@@ -9483,8 +9484,20 @@ static void nl80211_post_doit(const struct genl_ops *ops, struct sk_buff *skb, 
			dev_put(info->user_ptr[1]);

		}

	}



	if (ops->internal_flags & NL80211_FLAG_NEED_RTNL)

		rtnl_unlock();



	/* If needed, clear the netlink message payload from the SKB

	 * as it might contain key data that shouldn't stick around on

	 * the heap after the SKB is freed. The netlink message header

	 * is still needed for further processing, so leave it intact.

	 */

	if (ops->internal_flags & NL80211_FLAG_CLEAR_SKB) {

		struct nlmsghdr *nlh = nlmsg_hdr(skb);



		memset(nlmsg_data(nlh), 0, nlmsg_len(nlh));

	}

}



static const struct genl_ops nl80211_ops[] = {
@@ -9552,7 +9565,8 @@ static const struct genl_ops nl80211_ops[] = { 
		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

				  NL80211_FLAG_NEED_RTNL |

				  NL80211_FLAG_CLEAR_SKB,

	},

	{

		.cmd = NL80211_CMD_NEW_KEY,
@@ -9560,7 +9574,8 @@ static const struct genl_ops nl80211_ops[] = { 
		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

				  NL80211_FLAG_NEED_RTNL |

				  NL80211_FLAG_CLEAR_SKB,

	},

	{

		.cmd = NL80211_CMD_DEL_KEY,
@@ -9738,7 +9753,8 @@ static const struct genl_ops nl80211_ops[] = { 
		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

				  NL80211_FLAG_NEED_RTNL |

				  NL80211_FLAG_CLEAR_SKB,

	},

	{

		.cmd = NL80211_CMD_ASSOCIATE,
@@ -9972,7 +9988,8 @@ static const struct genl_ops nl80211_ops[] = { 
		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

				  NL80211_FLAG_NEED_RTNL |

				  NL80211_FLAG_CLEAR_SKB,

	},

	{

		.cmd = NL80211_CMD_TDLS_MGMT,