diff options
| author | Eric Dumazet | 2017-10-08 21:44:52 -0700 |
|---|---|---|
| committer | David S. Miller | 2017-10-09 20:55:01 -0700 |
| commit | fbb1fb4ad415cb31ce944f65a5ca700aaf73a227 (patch) | |
| tree | a7b1d3fddab2353229b73daaa103904ce539414d | |
| parent | 9f1c2674b328a69ab5a9b5a1c52405795ee4163f (diff) | |
net: defer call to cgroup_sk_alloc()
sk_clone_lock() might run while TCP/DCCP listener already vanished.
In order to prevent use after free, it is better to defer cgroup_sk_alloc()
to the point we know both parent and child exist, and from process context.
Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | kernel/cgroup/cgroup.c | 11 | ||||
| -rw-r--r-- | net/core/sock.c | 3 | ||||
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 5 |
3 files changed, 6 insertions, 13 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 44857278eb8a..3380a3e49af5 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5709,17 +5709,6 @@ 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)); - return; - } - rcu_read_lock(); while (true) { diff --git a/net/core/sock.c b/net/core/sock.c index 70c6ccbdf49f..4499e3153813 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1680,6 +1680,7 @@ 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; + memset(&newsk->sk_cgrp_data, 0, sizeof(newsk->sk_cgrp_data)); atomic_set(&newsk->sk_drops, 0); newsk->sk_send_head = NULL; @@ -1718,8 +1719,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) newsk->sk_incoming_cpu = raw_smp_processor_id(); atomic64_set(&newsk->sk_cookie, 0); - cgroup_sk_alloc(&newsk->sk_cgrp_data); - /* * Before updating sk_refcnt, we must commit prior changes to memory * (Documentation/RCU/rculist_nulls.txt for details) diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 67aec7a10686..d32c74507314 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -26,6 +26,8 @@ #include <net/tcp.h> #include <net/sock_reuseport.h> #include <net/addrconf.h> +#include <net/cls_cgroup.h> +#include <net/netprio_cgroup.h> #ifdef INET_CSK_DEBUG const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n"; @@ -476,6 +478,9 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern) spin_unlock_bh(&queue->fastopenq.lock); } mem_cgroup_sk_alloc(newsk); + cgroup_sk_alloc(&newsk->sk_cgrp_data); + sock_update_classid(&newsk->sk_cgrp_data); + sock_update_netprioidx(&newsk->sk_cgrp_data); out: release_sock(sk); if (req) |