From 4aaa1685f750b293316d2a09cde2ea25be2a5de2 Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Thu, 30 Jun 2022 15:17:54 -0700
Subject: [PATCH] mptcp: never fetch fwd memory from the subflow
The memory accounting is broken in such exceptional code
path, and after commit 4890b686f408 ("net: keep sk->sk_forward_alloc
as small as possible") we can't find much help there.
Drop the broken code.
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>
---
net/mptcp/protocol.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 883bea93c2aee..9a6a4ab337dcf 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -328,15 +328,10 @@ static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size)
amt = sk_mem_pages(size);
amount = amt << PAGE_SHIFT;
- msk->rmem_fwd_alloc += amount;
- if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV)) {
- if (ssk->sk_forward_alloc < amount) {
- msk->rmem_fwd_alloc -= amount;
- return false;
- }
+ if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV))
+ return false;
- ssk->sk_forward_alloc -= amount;
- }
+ msk->rmem_fwd_alloc += amount;
return true;
}