5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paolo Abeni <pabeni@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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);
}
--
2.43.0
