From ec5b0f605b105457f257f2870acad4a5d463984b Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 13 Apr 2022 10:35:42 -0700 Subject: net/sched: cls_u32: fix possible leak in u32_init_knode() While investigating a related syzbot report, I found that whenever call to tcf_exts_init() from u32_init_knode() is failing, we end up with an elevated refcount on ht->refcnt To avoid that, only increase the refcount after all possible errors have been evaluated. Fixes: b9a24bb76bf6 ("net_sched: properly handle failure case of tcf_exts_init()") Signed-off-by: Eric Dumazet Cc: Cong Wang Cc: Jiri Pirko Acked-by: Jamal Hadi Salim Signed-off-by: Jakub Kicinski --- net/sched/cls_u32.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index fcba6c43ba50..4d27300c287c 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -815,10 +815,6 @@ static struct tc_u_knode *u32_init_knode(struct net *net, struct tcf_proto *tp, new->flags = n->flags; RCU_INIT_POINTER(new->ht_down, ht); - /* bump reference count as long as we hold pointer to structure */ - if (ht) - ht->refcnt++; - #ifdef CONFIG_CLS_U32_PERF /* Statistics may be incremented by readers during update * so we must keep them in tact. When the node is later destroyed @@ -840,6 +836,10 @@ static struct tc_u_knode *u32_init_knode(struct net *net, struct tcf_proto *tp, return NULL; } + /* bump reference count as long as we hold pointer to structure */ + if (ht) + ht->refcnt++; + return new; } -- cgit v1.2.3-59-g8ed1b