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authorCong Wang <xiyou.wangcong@gmail.com>2018-09-04 14:54:55 -0700
committerDavid S. Miller <davem@davemloft.net>2018-09-06 21:49:18 -0700
commit8f5c5fcf353302374b36232d6885c1a3b579e5ca (patch)
tree9dc9fc708ad4252bb2ecec4e9c250ea15ab897ee /net/tipc
parent6da410d97ffa486eb0379236d5444e5f4527c07a (diff)
tipc: call start and done ops directly in __tipc_nl_compat_dumpit()
__tipc_nl_compat_dumpit() uses a netlink_callback on stack, so the only way to align it with other ->dumpit() call path is calling tipc_dump_start() and tipc_dump_done() directly inside it. Otherwise ->dumpit() would always get NULL from cb->args[]. But tipc_dump_start() uses sock_net(cb->skb->sk) to retrieve net pointer, the cb->skb here doesn't set skb->sk, the net pointer is saved in msg->net instead, so introduce a helper function __tipc_dump_start() to pass in msg->net. Ying pointed out cb->args[0...3] are already used by other callbacks on this call path, so we can't use cb->args[0] any more, use cb->args[4] instead. Fixes: 9a07efa9aea2 ("tipc: switch to rhashtable iterator") Reported-and-tested-by: syzbot+e93a2c41f91b8e2c7d9b@syzkaller.appspotmail.com Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc')
-rw-r--r--net/tipc/netlink_compat.c2
-rw-r--r--net/tipc/socket.c17
-rw-r--r--net/tipc/socket.h1
3 files changed, 14 insertions, 6 deletions
diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c
index a2f76743c73a..82f665728382 100644
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -185,6 +185,7 @@ static int __tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd,
return -ENOMEM;
buf->sk = msg->dst_sk;
+ __tipc_dump_start(&cb, msg->net);
do {
int rem;
@@ -216,6 +217,7 @@ static int __tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd,
err = 0;
err_out:
+ tipc_dump_done(&cb);
kfree_skb(buf);
if (err == -EMSGSIZE) {
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index a0ff8bffc96b..3f03ddd0e35b 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3230,7 +3230,7 @@ int tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
struct netlink_callback *cb,
struct tipc_sock *tsk))
{
- struct rhashtable_iter *iter = (void *)cb->args[0];
+ struct rhashtable_iter *iter = (void *)cb->args[4];
struct tipc_sock *tsk;
int err;
@@ -3266,8 +3266,14 @@ EXPORT_SYMBOL(tipc_nl_sk_walk);
int tipc_dump_start(struct netlink_callback *cb)
{
- struct rhashtable_iter *iter = (void *)cb->args[0];
- struct net *net = sock_net(cb->skb->sk);
+ return __tipc_dump_start(cb, sock_net(cb->skb->sk));
+}
+EXPORT_SYMBOL(tipc_dump_start);
+
+int __tipc_dump_start(struct netlink_callback *cb, struct net *net)
+{
+ /* tipc_nl_name_table_dump() uses cb->args[0...3]. */
+ struct rhashtable_iter *iter = (void *)cb->args[4];
struct tipc_net *tn = tipc_net(net);
if (!iter) {
@@ -3275,17 +3281,16 @@ int tipc_dump_start(struct netlink_callback *cb)
if (!iter)
return -ENOMEM;
- cb->args[0] = (long)iter;
+ cb->args[4] = (long)iter;
}
rhashtable_walk_enter(&tn->sk_rht, iter);
return 0;
}
-EXPORT_SYMBOL(tipc_dump_start);
int tipc_dump_done(struct netlink_callback *cb)
{
- struct rhashtable_iter *hti = (void *)cb->args[0];
+ struct rhashtable_iter *hti = (void *)cb->args[4];
rhashtable_walk_exit(hti);
kfree(hti);
diff --git a/net/tipc/socket.h b/net/tipc/socket.h
index d43032e26532..5e575f205afe 100644
--- a/net/tipc/socket.h
+++ b/net/tipc/socket.h
@@ -69,5 +69,6 @@ int tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
struct netlink_callback *cb,
struct tipc_sock *tsk));
int tipc_dump_start(struct netlink_callback *cb);
+int __tipc_dump_start(struct netlink_callback *cb, struct net *net);
int tipc_dump_done(struct netlink_callback *cb);
#endif