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authorNeil Horman <nhorman@tuxdriver.com>2012-02-10 05:43:38 +0000
committerDavid S. Miller <davem@davemloft.net>2012-02-10 15:08:57 -0500
commit2b73bc65e2771372c818db7955709c8caedbf8b9 (patch)
tree4cd1bfe8284d9266d45f5de11e3f4d8fbfcdbf4f
parentf5c38208d32412d72b97a4f0d44af0eb39feb20b (diff)
netprio_cgroup: fix wrong memory access when NETPRIO_CGROUP=m
When the netprio_cgroup module is not loaded, net_prio_subsys_id is -1, and so sock_update_prioidx() accesses cgroup_subsys array with negative index subsys[-1]. Make the code resembles cls_cgroup code, which is bug free. Origionally-authored-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: "David S. Miller" <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/netprio_cgroup.h48
-rw-r--r--net/core/sock.c7
2 files changed, 42 insertions, 13 deletions
diff --git a/include/net/netprio_cgroup.h b/include/net/netprio_cgroup.h
index 7b2d43139c8e..d58fdec47597 100644
--- a/include/net/netprio_cgroup.h
+++ b/include/net/netprio_cgroup.h
@@ -37,19 +37,51 @@ extern int net_prio_subsys_id;
extern void sock_update_netprioidx(struct sock *sk);
-static inline struct cgroup_netprio_state
- *task_netprio_state(struct task_struct *p)
+#if IS_BUILTIN(CONFIG_NETPRIO_CGROUP)
+
+static inline u32 task_netprioidx(struct task_struct *p)
{
-#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
- return container_of(task_subsys_state(p, net_prio_subsys_id),
- struct cgroup_netprio_state, css);
-#else
- return NULL;
-#endif
+ struct cgroup_netprio_state *state;
+ u32 idx;
+
+ rcu_read_lock();
+ state = container_of(task_subsys_state(p, net_prio_subsys_id),
+ struct cgroup_netprio_state, css);
+ idx = state->prioidx;
+ rcu_read_unlock();
+ return idx;
+}
+
+#elif IS_MODULE(CONFIG_NETPRIO_CGROUP)
+
+static inline u32 task_netprioidx(struct task_struct *p)
+{
+ struct cgroup_netprio_state *state;
+ int subsys_id;
+ u32 idx = 0;
+
+ rcu_read_lock();
+ subsys_id = rcu_dereference_index_check(net_prio_subsys_id,
+ rcu_read_lock_held());
+ if (subsys_id >= 0) {
+ state = container_of(task_subsys_state(p, subsys_id),
+ struct cgroup_netprio_state, css);
+ idx = state->prioidx;
+ }
+ rcu_read_unlock();
+ return idx;
}
#else
+static inline u32 task_netprioidx(struct task_struct *p)
+{
+ return 0;
+}
+
+#endif /* CONFIG_NETPRIO_CGROUP */
+
+#else
#define sock_update_netprioidx(sk)
#endif
diff --git a/net/core/sock.c b/net/core/sock.c
index 3e81fd2e3c75..02f8dfe320b7 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1171,13 +1171,10 @@ EXPORT_SYMBOL(sock_update_classid);
void sock_update_netprioidx(struct sock *sk)
{
- struct cgroup_netprio_state *state;
if (in_interrupt())
return;
- rcu_read_lock();
- state = task_netprio_state(current);
- sk->sk_cgrp_prioidx = state ? state->prioidx : 0;
- rcu_read_unlock();
+
+ sk->sk_cgrp_prioidx = task_netprioidx(current);
}
EXPORT_SYMBOL_GPL(sock_update_netprioidx);
#endif