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| author |   Eric Dumazet <edumazet@google.com> | 2019-10-14 06:04:38 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-10-16 12:20:17 -0700 |
| commit | 2ca4f6ca4562594ef161e4140c2a5e0e5282967b (patch) | |
| tree | 9196047d3ab696992874cb25df1958ba90ea5d6c | |
| parent | Revert "blackhole_netdev: fix syzkaller reported issue" (diff) | |
| download | linux-dev-2ca4f6ca4562594ef161e4140c2a5e0e5282967b.tar.xz linux-dev-2ca4f6ca4562594ef161e4140c2a5e0e5282967b.zip | |
rxrpc: use rcu protection while reading sk->sk_user_data
We need to extend the rcu_read_lock() section in rxrpc_error_report()
and use rcu_dereference_sk_user_data() instead of plain access
to sk->sk_user_data to make sure all rules are respected.
The compiler wont reload sk->sk_user_data at will, and RCU rules
prevent memory beeing freed too soon.
Fixes: f0308fb07080 ("rxrpc: Fix possible NULL pointer access in ICMP handling")
Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/rxrpc/peer_event.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c index 61451281d74a..48f67a9b1037 100644 --- a/net/rxrpc/peer_event.c +++ b/net/rxrpc/peer_event.c @@ -147,13 +147,16 @@ void rxrpc_error_report(struct sock *sk) { struct sock_exterr_skb *serr; struct sockaddr_rxrpc srx; - struct rxrpc_local *local = sk->sk_user_data; + struct rxrpc_local *local; struct rxrpc_peer *peer; struct sk_buff *skb; - if (unlikely(!local)) + rcu_read_lock(); + local = rcu_dereference_sk_user_data(sk); + if (unlikely(!local)) { + rcu_read_unlock(); return; - + } _enter("%p{%d}", sk, local->debug_id); /* Clear the outstanding error value on the socket so that it doesn't @@ -163,6 +166,7 @@ void rxrpc_error_report(struct sock *sk) skb = sock_dequeue_err_skb(sk); if (!skb) { + rcu_read_unlock(); _leave("UDP socket errqueue empty"); return; } @@ -170,11 +174,11 @@ void rxrpc_error_report(struct sock *sk) serr = SKB_EXT_ERR(skb); if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) { _leave("UDP empty message"); + rcu_read_unlock(); rxrpc_free_skb(skb, rxrpc_skb_freed); return; } - rcu_read_lock(); peer = rxrpc_lookup_peer_icmp_rcu(local, skb, &srx); if (peer && !rxrpc_get_peer_maybe(peer)) peer = NULL; |