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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2016-12-05 15:28:21 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-05 19:43:42 -0500 |
| commit | ed5d7788a934a4b6d6d025e948ed4da496b4f12e (patch) | |
| tree | 9f10caf66c776a0ea3d55504e647897408105996 /net/netlink | |
| parent | ffe3bb85c19e1dbf96cc13aad823ae0a8855d066 (diff) | |
| download | linux-ed5d7788a934a4b6d6d025e948ed4da496b4f12e.tar.gz linux-ed5d7788a934a4b6d6d025e948ed4da496b4f12e.tar.bz2 linux-ed5d7788a934a4b6d6d025e948ed4da496b4f12e.zip | |
netlink: Do not schedule work from sk_destruct
It is wrong to schedule a work from sk_destruct using the socket
as the memory reserve because the socket will be freed immediately
after the return from sk_destruct.
Instead we should do the deferral prior to sk_free.
This patch does just that.
Fixes: 707693c8a498 ("netlink: Call cb->done from a worker thread")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
| -rw-r--r-- | net/netlink/af_netlink.c | 32 |
1 files changed, 15 insertions, 17 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 602e5ebe9db3..246f29d365c0 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -322,11 +322,13 @@ static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) sk_mem_charge(sk, skb->truesize); } -static void __netlink_sock_destruct(struct sock *sk) +static void netlink_sock_destruct(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); if (nlk->cb_running) { + if (nlk->cb.done) + nlk->cb.done(&nlk->cb); module_put(nlk->cb.module); kfree_skb(nlk->cb.skb); } @@ -348,21 +350,7 @@ static void netlink_sock_destruct_work(struct work_struct *work) struct netlink_sock *nlk = container_of(work, struct netlink_sock, work); - nlk->cb.done(&nlk->cb); - __netlink_sock_destruct(&nlk->sk); -} - -static void netlink_sock_destruct(struct sock *sk) -{ - struct netlink_sock *nlk = nlk_sk(sk); - - if (nlk->cb_running && nlk->cb.done) { - INIT_WORK(&nlk->work, netlink_sock_destruct_work); - schedule_work(&nlk->work); - return; - } - - __netlink_sock_destruct(sk); + sk_free(&nlk->sk); } /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on @@ -667,8 +655,18 @@ out_module: static void deferred_put_nlk_sk(struct rcu_head *head) { struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); + struct sock *sk = &nlk->sk; + + if (!atomic_dec_and_test(&sk->sk_refcnt)) + return; + + if (nlk->cb_running && nlk->cb.done) { + INIT_WORK(&nlk->work, netlink_sock_destruct_work); + schedule_work(&nlk->work); + return; + } - sock_put(&nlk->sk); + sk_free(sk); } static int netlink_release(struct socket *sock) |