diff options
| author | Neil Horman <nhorman@tuxdriver.com> | 2012-02-10 09:43:38 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-02-11 00:08:57 +0400 |
| commit | 2b73bc65e2771372c818db7955709c8caedbf8b9 (patch) | |
| tree | 4cd1bfe8284d9266d45f5de11e3f4d8fbfcdbf4f | |
| parent | f5c38208d32412d72b97a4f0d44af0eb39feb20b (diff) | |
| download | linux-2b73bc65e2771372c818db7955709c8caedbf8b9.tar.xz | |
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.h | 48 | ||||
| -rw-r--r-- | net/core/sock.c | 7 |
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 |