tipc: fix race between poll() and setsockopt()
Letting tipc_poll() dereference a socket's pointer to struct tipc_group
entails a race risk, as the group item may be deleted in a concurrent
tipc_sk_join() or tipc_sk_leave() thread.
We now move the 'open' flag in struct tipc_group to struct tipc_sock,
and let the former retain only a pointer to the moved field. This will
eliminate the race risk.
Reported-by: syzbot+799dafde0286795858ac@syzkaller.appspotmail.com
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/group.h b/net/tipc/group.h
index f4a596e..5996af6 100644
--- a/net/tipc/group.h
+++ b/net/tipc/group.h
@@ -43,7 +43,8 @@
struct tipc_msg;
struct tipc_group *tipc_group_create(struct net *net, u32 portid,
- struct tipc_group_req *mreq);
+ struct tipc_group_req *mreq,
+ bool *group_is_open);
void tipc_group_join(struct net *net, struct tipc_group *grp, int *sk_rcv_buf);
void tipc_group_delete(struct net *net, struct tipc_group *grp);
void tipc_group_add_member(struct tipc_group *grp, u32 node,
@@ -67,7 +68,6 @@
bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
int len, struct tipc_member **m);
bool tipc_group_bc_cong(struct tipc_group *grp, int len);
-bool tipc_group_is_open(struct tipc_group *grp);
void tipc_group_update_rcv_win(struct tipc_group *grp, int blks, u32 node,
u32 port, struct sk_buff_head *xmitq);
u16 tipc_group_bc_snd_nxt(struct tipc_group *grp);