From f10e0010fae8174dc20bdc872bcaa85baa925cb7 Mon Sep 17 00:00:00 2001 From: Su Yanjun Date: Wed, 6 Mar 2019 20:54:08 -0500 Subject: net: xfrm: Add '_rcu' tag for rcu protected pointer in netns_xfrm For rcu protected pointers, we'd better add '__rcu' for them. Once added '__rcu' tag for rcu protected pointer, the sparse tool reports warnings. net/xfrm/xfrm_user.c:1198:39: sparse: expected struct sock *sk net/xfrm/xfrm_user.c:1198:39: sparse: got struct sock [noderef] *nlsk [...] So introduce a new wrapper function of nlmsg_unicast to handle type conversions. This patch also fixes a direct access of a rcu protected socket. Fixes: be33690d8fcf("[XFRM]: Fix aevent related crash") Signed-off-by: Su Yanjun Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_user.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 8d4d52fd457b..944589832343 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1071,6 +1071,22 @@ static inline int xfrm_nlmsg_multicast(struct net *net, struct sk_buff *skb, return nlmsg_multicast(nlsk, skb, pid, group, GFP_ATOMIC); } +/* A similar wrapper like xfrm_nlmsg_multicast checking that nlsk is still + * available. + */ +static inline int xfrm_nlmsg_unicast(struct net *net, struct sk_buff *skb, + u32 pid) +{ + struct sock *nlsk = rcu_dereference(net->xfrm.nlsk); + + if (!nlsk) { + kfree_skb(skb); + return -EPIPE; + } + + return nlmsg_unicast(nlsk, skb, pid); +} + static inline unsigned int xfrm_spdinfo_msgsize(void) { return NLMSG_ALIGN(4) @@ -1195,7 +1211,7 @@ static int xfrm_get_spdinfo(struct sk_buff *skb, struct nlmsghdr *nlh, err = build_spdinfo(r_skb, net, sportid, seq, *flags); BUG_ON(err < 0); - return nlmsg_unicast(net->xfrm.nlsk, r_skb, sportid); + return xfrm_nlmsg_unicast(net, r_skb, sportid); } static inline unsigned int xfrm_sadinfo_msgsize(void) @@ -1254,7 +1270,7 @@ static int xfrm_get_sadinfo(struct sk_buff *skb, struct nlmsghdr *nlh, err = build_sadinfo(r_skb, net, sportid, seq, *flags); BUG_ON(err < 0); - return nlmsg_unicast(net->xfrm.nlsk, r_skb, sportid); + return xfrm_nlmsg_unicast(net, r_skb, sportid); } static int xfrm_get_sa(struct sk_buff *skb, struct nlmsghdr *nlh, @@ -1274,7 +1290,7 @@ static int xfrm_get_sa(struct sk_buff *skb, struct nlmsghdr *nlh, if (IS_ERR(resp_skb)) { err = PTR_ERR(resp_skb); } else { - err = nlmsg_unicast(net->xfrm.nlsk, resp_skb, NETLINK_CB(skb).portid); + err = xfrm_nlmsg_unicast(net, resp_skb, NETLINK_CB(skb).portid); } xfrm_state_put(x); out_noput: @@ -1337,7 +1353,7 @@ static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh, goto out; } - err = nlmsg_unicast(net->xfrm.nlsk, resp_skb, NETLINK_CB(skb).portid); + err = xfrm_nlmsg_unicast(net, resp_skb, NETLINK_CB(skb).portid); out: xfrm_state_put(x); @@ -1903,8 +1919,8 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, if (IS_ERR(resp_skb)) { err = PTR_ERR(resp_skb); } else { - err = nlmsg_unicast(net->xfrm.nlsk, resp_skb, - NETLINK_CB(skb).portid); + err = xfrm_nlmsg_unicast(net, resp_skb, + NETLINK_CB(skb).portid); } } else { xfrm_audit_policy_delete(xp, err ? 0 : 1, true); @@ -2062,7 +2078,7 @@ static int xfrm_get_ae(struct sk_buff *skb, struct nlmsghdr *nlh, err = build_aevent(r_skb, x, &c); BUG_ON(err < 0); - err = nlmsg_unicast(net->xfrm.nlsk, r_skb, NETLINK_CB(skb).portid); + err = xfrm_nlmsg_unicast(net, r_skb, NETLINK_CB(skb).portid); spin_unlock_bh(&x->lock); xfrm_state_put(x); return err; -- cgit