From 5781b2356cbecb0b73b06ec8c3897cabdfdd0928 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 13 Dec 2009 19:32:39 -0800 Subject: [PATCH] udp: udp_lib_get_port() fix Now we can have a large udp hash table, udp_lib_get_port() loop should be converted to a do {} while (cond) form, or we dont enter it at all if hash table size is exactly 65536. Reported-by: Yinghai Lu Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/udp.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 1f9534846ca9..f0126fdd7e04 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -216,9 +216,8 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum, * force rand to be an odd multiple of UDP_HTABLE_SIZE */ rand = (rand | 1) * (udptable->mask + 1); - for (last = first + udptable->mask + 1; - first != last; - first++) { + last = first + udptable->mask + 1; + do { hslot = udp_hashslot(udptable, net, first); bitmap_zero(bitmap, PORTS_PER_CHAIN); spin_lock_bh(&hslot->lock); @@ -238,7 +237,7 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum, snum += rand; } while (snum != first); spin_unlock_bh(&hslot->lock); - } + } while (++first != last); goto fail; } else { hslot = udp_hashslot(udptable, net, snum); -- 2.20.1