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authorJon Maloy <jon.maloy@ericsson.com>2018-01-17 16:42:46 +0100
committerDavid S. Miller <davem@davemloft.net>2018-01-19 15:12:21 -0500
commit60c2530696320ee6ffe4491c17079fa403790c98 (patch)
tree619bdaecd86e48c1962a6866e40ada7e09c5addc /net/tipc/group.c
parent30c3e9d470358a6741e00e1034a1ea85c6a516f0 (diff)
downloadlinux-60c2530696320ee6ffe4491c17079fa403790c98.tar.bz2
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>
Diffstat (limited to 'net/tipc/group.c')
-rw-r--r--net/tipc/group.c19
1 files changed, 8 insertions, 11 deletions
diff --git a/net/tipc/group.c b/net/tipc/group.c
index 497ee34bfab9..122162a31816 100644
--- a/net/tipc/group.c
+++ b/net/tipc/group.c
@@ -93,26 +93,21 @@ struct tipc_group {
u16 max_active;
u16 bc_snd_nxt;
u16 bc_ackers;
+ bool *open;
bool loopback;
bool events;
- bool open;
};
static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
int mtyp, struct sk_buff_head *xmitq);
-bool tipc_group_is_open(struct tipc_group *grp)
-{
- return grp->open;
-}
-
static void tipc_group_open(struct tipc_member *m, bool *wakeup)
{
*wakeup = false;
if (list_empty(&m->small_win))
return;
list_del_init(&m->small_win);
- m->group->open = true;
+ *m->group->open = true;
*wakeup = true;
}
@@ -170,7 +165,8 @@ int tipc_group_size(struct tipc_group *grp)
}
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)
{
u32 filter = TIPC_SUB_PORTS | TIPC_SUB_NO_STATUS;
bool global = mreq->scope != TIPC_NODE_SCOPE;
@@ -192,6 +188,7 @@ struct tipc_group *tipc_group_create(struct net *net, u32 portid,
grp->scope = mreq->scope;
grp->loopback = mreq->flags & TIPC_GROUP_LOOPBACK;
grp->events = mreq->flags & TIPC_GROUP_MEMBER_EVTS;
+ grp->open = group_is_open;
filter |= global ? TIPC_SUB_CLUSTER_SCOPE : TIPC_SUB_NODE_SCOPE;
if (tipc_topsrv_kern_subscr(net, portid, type, 0, ~0,
filter, &grp->subid))
@@ -430,7 +427,7 @@ bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
if (m->window >= len)
return false;
- grp->open = false;
+ *grp->open = false;
/* If not fully advertised, do it now to prevent mutual blocking */
adv = m->advertised;
@@ -453,7 +450,7 @@ bool tipc_group_bc_cong(struct tipc_group *grp, int len)
/* If prev bcast was replicast, reject until all receivers have acked */
if (grp->bc_ackers) {
- grp->open = false;
+ *grp->open = false;
return true;
}
if (list_empty(&grp->small_win))
@@ -800,7 +797,7 @@ void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
if (--grp->bc_ackers)
return;
list_del_init(&m->small_win);
- m->group->open = true;
+ *m->group->open = true;
*usr_wakeup = true;
tipc_group_update_member(m, 0);
return;