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author | 2021-07-09 17:20:51 -0700 | |
---|---|---|
committer | 2021-07-09 18:38:53 -0700 | |
commit | ce599c516386f09ca30848a1a4eb93d3fffbe187 (patch) | |
tree | 25e8811ed4d7a8fbfea62409158434e5e27ac77b /net/mptcp/protocol.c | |
parent | selftests: mptcp: fix case multiple subflows limited by server (diff) | |
download | linux-ce599c516386f09ca30848a1a4eb93d3fffbe187.tar.gz linux-ce599c516386f09ca30848a1a4eb93d3fffbe187.tar.bz2 linux-ce599c516386f09ca30848a1a4eb93d3fffbe187.zip |
mptcp: properly account bulk freed memory
After commit 879526030c8b ("mptcp: protect the rx path with
the msk socket spinlock") the rmem currently used by a given
msk is really sk_rmem_alloc - rmem_released.
The safety check in mptcp_data_ready() does not take the above
in due account, as a result legit incoming data is kept in
subflow receive queue with no reason, delaying or blocking
MPTCP-level ack generation.
This change addresses the issue introducing a new helper to fetch
the rmem memory and using it as needed. Additionally add a MIB
counter for the exceptional event described above - the peer is
misbehaving.
Finally, introduce the required annotation when rmem_released is
updated.
Fixes: 879526030c8b ("mptcp: protect the rx path with the msk socket spinlock")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/211
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp/protocol.c')
-rw-r--r-- | net/mptcp/protocol.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 7a5afa8c6866..a88924947815 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -474,7 +474,7 @@ static void mptcp_cleanup_rbuf(struct mptcp_sock *msk) bool cleanup, rx_empty; cleanup = (space > 0) && (space >= (old_space << 1)); - rx_empty = !atomic_read(&sk->sk_rmem_alloc); + rx_empty = !__mptcp_rmem(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); @@ -720,8 +720,10 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk) sk_rbuf = ssk_rbuf; /* over limit? can't append more skbs to msk, Also, no need to wake-up*/ - if (atomic_read(&sk->sk_rmem_alloc) > sk_rbuf) + if (__mptcp_rmem(sk) > sk_rbuf) { + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED); return; + } /* Wake-up the reader only for in-sequence data */ mptcp_data_lock(sk); @@ -1754,7 +1756,7 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, if (!(flags & MSG_PEEK)) { /* we will bulk release the skb memory later */ skb->destructor = NULL; - msk->rmem_released += skb->truesize; + WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize); __skb_unlink(skb, &msk->receive_queue); __kfree_skb(skb); } @@ -1873,7 +1875,7 @@ static void __mptcp_update_rmem(struct sock *sk) atomic_sub(msk->rmem_released, &sk->sk_rmem_alloc); sk_mem_uncharge(sk, msk->rmem_released); - msk->rmem_released = 0; + WRITE_ONCE(msk->rmem_released, 0); } static void __mptcp_splice_receive_queue(struct sock *sk) @@ -2380,7 +2382,7 @@ static int __mptcp_init_sock(struct sock *sk) msk->out_of_order_queue = RB_ROOT; msk->first_pending = NULL; msk->wmem_reserved = 0; - msk->rmem_released = 0; + WRITE_ONCE(msk->rmem_released, 0); msk->tx_pending_data = 0; msk->first = NULL; |