[PATCH 5.10 175/545] net: fix sk_wmem_schedule() and sk_rmem_schedule() errors

[Greg Kroah-Hartman]

From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit 7c80b038d23e1f4c7fcc311f43f83b8c60e7fb80 ]

If sk->sk_forward_alloc is 150000, and we need to schedule 150001 bytes,
we want to allocate 1 byte more (rounded up to one page),
instead of 150001 :/

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 include/net/sock.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 83854cec4a47..c72b0fc4c752 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1468,19 +1468,23 @@ static inline bool sk_has_account(struct sock *sk)
 
 static inline bool sk_wmem_schedule(struct sock *sk, int size)
 {
+	int delta;
+
 	if (!sk_has_account(sk))
 		return true;
-	return size <= sk->sk_forward_alloc ||
-		__sk_mem_schedule(sk, size, SK_MEM_SEND);
+	delta = size - sk->sk_forward_alloc;
+	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
 }
 
 static inline bool
 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
 {
+	int delta;
+
 	if (!sk_has_account(sk))
 		return true;
-	return size <= sk->sk_forward_alloc ||
-		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
+	delta = size - sk->sk_forward_alloc;
+	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
 		skb_pfmemalloc(skb);
 }
 
-- 
2.35.1