When an item of struct tipc_subscription is created, we fail to
initialize the two lists aggregated into the struct. This has so far
never been a problem, since the items are just added to a root
object by list_add(), which does not require the addee list to be
pre-initialized. However, syzbot is provoking situations where this
addition fails, whereupon the attempted removal if the item from
the list causes a crash.
This problem seems to always have been around, despite that the code
for creating this object was rewritten in commit 242e82cc95f6 ("tipc:
collapse subscription creation functions"), which is still in net-next.
We fix this for that commit by initializing the two lists properly.
Fixes: 242e82cc95f6 ("tipc: collapse subscription creation functions")
Reported-by: syzbot+0bb443b74ce09197e...@syzkaller.appspotmail.com
Signed-off-by: Jon Maloy <jon.ma...@ericsson.com>
---
net/tipc/subscr.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index 6925a98..b7d80bc 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -145,6 +145,8 @@ struct tipc_subscription *tipc_sub_subscribe(struct net
*net,
pr_warn("Subscription rejected, no memory\n");
return NULL;
}
+ INIT_LIST_HEAD(&sub->service_list);
+ INIT_LIST_HEAD(&sub->sub_list);
sub->net = net;
sub->conid = conid;
sub->inactive = false;
--
2.1.4
