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>
mariux64 · Feb 14, 2019 · 5bf325a · 5bf325a
1 parent 7c0db24
commit 5bf325a
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diff --git 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
@@ -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;