5.4-stable review patch. If anyone has any objections, please let me know.
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From: Paolo Abeni pabeni@redhat.com
[ Upstream commit fc9c273d6daaa9866f349bbe8cae25c67764c456 ]
Similar to the previous patch, plumb the RCU lock inside the ipmr_get_table(), provided a lockless variant and apply the latter in the few spots were the lock is already held.
Fixes: 709b46e8d90b ("net: Add compat ioctl support for the ipv4 multicast ioctl SIOCGETSGCNT") Fixes: f0ad0860d01e ("ipv4: ipmr: support multiple tables") Reviewed-by: David Ahern dsahern@kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/ipmr.c | 42 +++++++++++++++++++++++++++++------------- 1 file changed, 29 insertions(+), 13 deletions(-)
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 11f916646d34d..8e31c277fe465 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -129,7 +129,7 @@ static struct mr_table *ipmr_mr_table_iter(struct net *net, return ret; }
-static struct mr_table *ipmr_get_table(struct net *net, u32 id) +static struct mr_table *__ipmr_get_table(struct net *net, u32 id) { struct mr_table *mrt;
@@ -140,6 +140,16 @@ static struct mr_table *ipmr_get_table(struct net *net, u32 id) return NULL; }
+static struct mr_table *ipmr_get_table(struct net *net, u32 id) +{ + struct mr_table *mrt; + + rcu_read_lock(); + mrt = __ipmr_get_table(net, id); + rcu_read_unlock(); + return mrt; +} + static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4, struct mr_table **mrt) { @@ -181,7 +191,7 @@ static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
arg->table = fib_rule_get_table(rule, arg);
- mrt = ipmr_get_table(rule->fr_net, arg->table); + mrt = __ipmr_get_table(rule->fr_net, arg->table); if (!mrt) return -EAGAIN; res->mrt = mrt; @@ -312,6 +322,8 @@ static struct mr_table *ipmr_get_table(struct net *net, u32 id) return net->ipv4.mrt; }
+#define __ipmr_get_table ipmr_get_table + static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4, struct mr_table **mrt) { @@ -400,7 +412,7 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id) if (id != RT_TABLE_DEFAULT && id >= 1000000000) return ERR_PTR(-EINVAL);
- mrt = ipmr_get_table(net, id); + mrt = __ipmr_get_table(net, id); if (mrt) return mrt;
@@ -1391,7 +1403,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, goto out_unlock; }
- mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); + mrt = __ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT); if (!mrt) { ret = -ENOENT; goto out_unlock; @@ -2264,11 +2276,13 @@ int ipmr_get_route(struct net *net, struct sk_buff *skb, struct mr_table *mrt; int err;
- mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); - if (!mrt) + rcu_read_lock(); + mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT); + if (!mrt) { + rcu_read_unlock(); return -ENOENT; + }
- rcu_read_lock(); cache = ipmr_cache_find(mrt, saddr, daddr); if (!cache && skb->dev) { int vif = ipmr_find_vif(mrt, skb->dev); @@ -2557,7 +2571,7 @@ static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
- mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT); + mrt = __ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT); if (!mrt) { err = -ENOENT; goto errout_free; @@ -2609,7 +2623,7 @@ static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb) if (filter.table_id) { struct mr_table *mrt;
- mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id); + mrt = __ipmr_get_table(sock_net(skb->sk), filter.table_id); if (!mrt) { if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR) return skb->len; @@ -2717,7 +2731,7 @@ static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh, break; } } - mrt = ipmr_get_table(net, tblid); + mrt = __ipmr_get_table(net, tblid); if (!mrt) { ret = -ENOENT; goto out; @@ -2922,13 +2936,15 @@ static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos) struct net *net = seq_file_net(seq); struct mr_table *mrt;
- mrt = ipmr_get_table(net, RT_TABLE_DEFAULT); - if (!mrt) + rcu_read_lock(); + mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT); + if (!mrt) { + rcu_read_unlock(); return ERR_PTR(-ENOENT); + }
iter->mrt = mrt;
- rcu_read_lock(); return mr_vif_seq_start(seq, pos); }