From: Cong Wang <xiyou.wangcong@gmail.com>
To: netdev@vger.kernel.org
Cc: "Cong Wang" <xiyou.wangcong@gmail.com>,
"Cameron Berkenpas" <cam@neo-zeon.de>,
"Peter Geis" <pgwipeout@gmail.com>,
"Lu Fengqi" <lufq.fnst@cn.fujitsu.com>,
"Daniël Sonck" <dsonck92@gmail.com>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Zefan Li" <lizefan@huawei.com>, "Tejun Heo" <tj@kernel.org>
Subject: [Patch net] cgroup: fix cgroup_sk_alloc() for sk_clone_lock()
Date: Tue, 16 Jun 2020 11:03:52 -0700 [thread overview]
Message-ID: <20200616180352.18602-1-xiyou.wangcong@gmail.com> (raw)
When we clone a socket in sk_clone_lock(), its sk_cgrp_data is
copied, so the cgroup refcnt must be taken too. And, unlike the
sk_alloc() path, sock_update_netprioidx() is not called here.
Therefore, it is safe and necessary to grab the cgroup refcnt
even when cgroup_sk_alloc is disabled.
sk_clone_lock() is in BH context anyway, the in_interrupt()
would terminate this function if called there. And for sk_alloc()
skcd->val is always zero. So it's safe to factor out the code
to make it more readable.
Fixes: 090e28b229af92dc5b ("netprio_cgroup: Fix unlimited memory leak of v2 cgroups")
Reported-by: Cameron Berkenpas <cam@neo-zeon.de>
Reported-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reported-by: Daniël Sonck <dsonck92@gmail.com>
Tested-by: Cameron Berkenpas <cam@neo-zeon.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
include/linux/cgroup.h | 2 ++
kernel/cgroup/cgroup.c | 26 ++++++++++++++------------
net/core/sock.c | 2 +-
3 files changed, 17 insertions(+), 13 deletions(-)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 4598e4da6b1b..818dc7b3ed6c 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -822,6 +822,7 @@ extern spinlock_t cgroup_sk_update_lock;
void cgroup_sk_alloc_disable(void);
void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
+void cgroup_sk_clone(struct sock_cgroup_data *skcd);
void cgroup_sk_free(struct sock_cgroup_data *skcd);
static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
@@ -847,6 +848,7 @@ static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
#else /* CONFIG_CGROUP_DATA */
static inline void cgroup_sk_alloc(struct sock_cgroup_data *skcd) {}
+static inline void cgroup_sk_clone(struct sock_cgroup_data *skcd) {}
static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {}
#endif /* CONFIG_CGROUP_DATA */
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 1ea181a58465..6377045b7096 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6442,18 +6442,6 @@ void cgroup_sk_alloc(struct sock_cgroup_data *skcd)
if (cgroup_sk_alloc_disabled)
return;
- /* Socket clone path */
- if (skcd->val) {
- /*
- * We might be cloning a socket which is left in an empty
- * cgroup and the cgroup might have already been rmdir'd.
- * Don't use cgroup_get_live().
- */
- cgroup_get(sock_cgroup_ptr(skcd));
- cgroup_bpf_get(sock_cgroup_ptr(skcd));
- return;
- }
-
/* Don't associate the sock with unrelated interrupted task's cgroup. */
if (in_interrupt())
return;
@@ -6475,6 +6463,20 @@ void cgroup_sk_alloc(struct sock_cgroup_data *skcd)
rcu_read_unlock();
}
+void cgroup_sk_clone(struct sock_cgroup_data *skcd)
+{
+ /* Socket clone path */
+ if (skcd->val) {
+ /*
+ * We might be cloning a socket which is left in an empty
+ * cgroup and the cgroup might have already been rmdir'd.
+ * Don't use cgroup_get_live().
+ */
+ cgroup_get(sock_cgroup_ptr(skcd));
+ cgroup_bpf_get(sock_cgroup_ptr(skcd));
+ }
+}
+
void cgroup_sk_free(struct sock_cgroup_data *skcd)
{
struct cgroup *cgrp = sock_cgroup_ptr(skcd);
diff --git a/net/core/sock.c b/net/core/sock.c
index 6c4acf1f0220..b62f06fa5e37 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1925,7 +1925,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
/* sk->sk_memcg will be populated at accept() time */
newsk->sk_memcg = NULL;
- cgroup_sk_alloc(&newsk->sk_cgrp_data);
+ cgroup_sk_clone(&newsk->sk_cgrp_data);
rcu_read_lock();
filter = rcu_dereference(sk->sk_filter);
--
2.26.2
next reply other threads:[~2020-06-16 18:04 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-16 18:03 Cong Wang [this message]
2020-06-18 1:44 ` [Patch net] cgroup: fix cgroup_sk_alloc() for sk_clone_lock() Zefan Li
2020-06-18 19:19 ` Cong Wang
2020-06-18 19:36 ` Roman Gushchin
2020-06-18 21:09 ` Cong Wang
2020-06-18 21:26 ` Roman Gushchin
2020-06-18 22:45 ` Peter Geis
2020-06-19 6:40 ` Zefan Li
2020-06-19 19:51 ` Cong Wang
2020-06-20 0:45 ` Zefan Li
2020-06-20 0:51 ` Zefan Li
2020-06-20 3:31 ` Cong Wang
2020-06-20 7:52 ` Zefan Li
2020-06-20 16:04 ` Roman Gushchin
2020-06-23 22:21 ` Roman Gushchin
2020-06-26 5:23 ` Cameron Berkenpas
2020-06-26 17:58 ` Cong Wang
2020-06-26 22:03 ` Cameron Berkenpas
2020-06-27 22:59 ` Cameron Berkenpas
2020-06-30 22:16 ` Cong Wang
2020-06-27 23:41 ` Roman Gushchin
2020-06-30 22:22 ` Cong Wang
2020-06-30 22:48 ` Roman Gushchin
2020-07-01 1:18 ` Zefan Li
2020-07-02 4:48 ` Cong Wang
2020-07-02 8:12 ` Thomas Lamprecht
2020-07-02 16:02 ` Roman Gushchin
2020-07-02 16:24 ` Peter Geis
2020-07-03 1:17 ` Zefan Li
2020-06-20 0:51 ` Roman Gushchin
2020-06-20 1:00 ` Zefan Li
2020-06-20 1:14 ` Roman Gushchin
2020-06-20 2:48 ` Zefan Li
2020-06-20 3:00 ` Cong Wang
2020-06-20 15:57 ` Roman Gushchin
2020-06-22 18:14 ` Cong Wang
2020-06-22 20:39 ` Roman Gushchin
2020-06-23 8:45 ` Zhang,Qiang
2020-06-23 17:56 ` Cong Wang
2020-06-23 8:54 ` Zhang,Qiang
2020-06-23 9:01 ` Zhang,Qiang
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