From: Eric Dumazet <edumazet@google.com>
Date: Tue, 12 Feb 2019 20:26:27 +0000 (-0800)
Subject: net: fix possible overflow in __sk_mem_raise_allocated()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=5bf325a53202b8728cf7013b72688c46071e212e;p=openwrt%2Fstaging%2Fblogic.git

net: fix possible overflow in __sk_mem_raise_allocated()

With many active TCP sockets, fat TCP sockets could fool
__sk_mem_raise_allocated() thanks to an overflow.

They would increase their share of the memory, instead
of decreasing it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/net/sock.h b/include/net/sock.h
index 2b229f7be8eb..f43f935cb113 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1277,7 +1277,7 @@ static inline void sk_sockets_allocated_inc(struct sock *sk)
 	percpu_counter_inc(sk->sk_prot->sockets_allocated);
 }
 
-static inline int
+static inline u64
 sk_sockets_allocated_read_positive(struct sock *sk)
 {
 	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
diff --git a/net/core/sock.c b/net/core/sock.c
index 6aa2e7e0b4fb..bc3512f230a3 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2380,7 +2380,7 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
 	}
 
 	if (sk_has_memory_pressure(sk)) {
-		int alloc;
+		u64 alloc;
 
 		if (!sk_under_memory_pressure(sk))
 			return 1;