From: David Miller <davem@davemloft.net>
Date: Fri, 22 Dec 2006 19:56:21 +0000 (-0800)
Subject: [PATCH] UDP: Fix reversed logic in udp_get_port()
X-Git-Tag: v2.6.19.2~29
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3629bc276335cfc6650c6b7119ea8b1e2518ec6c;p=thirdparty%2Fkernel%2Fstable.git

[PATCH] UDP: Fix reversed logic in udp_get_port()

When this code was converted to use sk_for_each() the
logic for the "best hash chain length" code was reversed,
breaking everything.

The original code was of the form:

			size = 0;
			do {
				if (++size >= best_size_so_far)
					goto next;
			} while ((sk = sk->next) != NULL);
			best_size_so_far = size;
			best = result;
		next:;

and this got converted into:

			sk_for_each(sk2, node, head)
				if (++size < best_size_so_far) {
					best_size_so_far = size;
					best = result;
				}

Which does something very very different from the original.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 9e1bd374875e2..404dd21479638 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -167,11 +167,14 @@ int udp_get_port(struct sock *sk, unsigned short snum,
 				goto gotit;
 			}
 			size = 0;
-			sk_for_each(sk2, node, head)
-				if (++size < best_size_so_far) {
-					best_size_so_far = size;
-					best = result;
-				}
+			sk_for_each(sk2, node, head) {
+				if (++size >= best_size_so_far)
+					goto next;
+			}
+			best_size_so_far = size;
+			best = result;
+		next:
+			;
 		}
 		result = best;
 		for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {