From: Eric Dumazet edumazet@google.com
stable inclusion from stable-v5.10.113 commit 0ac8f83d8f6471e39b3cfe8ee48560df3bf9c451 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5ISAH
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
[ Upstream commit ec5b0f605b105457f257f2870acad4a5d463984b ]
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 edumazet@google.com Cc: Cong Wang xiyou.wangcong@gmail.com Cc: Jiri Pirko jiri@resnulli.us Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- net/sched/cls_u32.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index b61db335c49d..da042bc8b239 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -814,10 +814,6 @@ 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 @@ -839,6 +835,10 @@ 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; }