net: net_secret should not depend on TCP
[ Upstream commit 9a3bab6b05383f1e4c3716b3615500c51285959e ]
A host might need net_secret[] and never open a single socket.
Problem added in commit aebda156a570782
("net: defer net_secret[] initialization")
Based on prior patch from Hannes Frederic Sowa.
Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@strressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
index 6a2f13c..3f1ec15 100644
--- a/net/core/secure_seq.c
+++ b/net/core/secure_seq.c
@@ -10,11 +10,24 @@
#include <net/secure_seq.h>
-static u32 net_secret[MD5_MESSAGE_BYTES / 4] ____cacheline_aligned;
+#define NET_SECRET_SIZE (MD5_MESSAGE_BYTES / 4)
-void net_secret_init(void)
+static u32 net_secret[NET_SECRET_SIZE] ____cacheline_aligned;
+
+static void net_secret_init(void)
{
- get_random_bytes(net_secret, sizeof(net_secret));
+ u32 tmp;
+ int i;
+
+ if (likely(net_secret[0]))
+ return;
+
+ for (i = NET_SECRET_SIZE; i > 0;) {
+ do {
+ get_random_bytes(&tmp, sizeof(tmp));
+ } while (!tmp);
+ cmpxchg(&net_secret[--i], 0, tmp);
+ }
}
#ifdef CONFIG_INET
@@ -42,6 +55,7 @@
u32 hash[MD5_DIGEST_WORDS];
u32 i;
+ net_secret_init();
memcpy(hash, saddr, 16);
for (i = 0; i < 4; i++)
secret[i] = net_secret[i] + (__force u32)daddr[i];
@@ -63,6 +77,7 @@
u32 hash[MD5_DIGEST_WORDS];
u32 i;
+ net_secret_init();
memcpy(hash, saddr, 16);
for (i = 0; i < 4; i++)
secret[i] = net_secret[i] + (__force u32) daddr[i];
@@ -82,6 +97,7 @@
{
u32 hash[MD5_DIGEST_WORDS];
+ net_secret_init();
hash[0] = (__force __u32) daddr;
hash[1] = net_secret[13];
hash[2] = net_secret[14];
@@ -96,6 +112,7 @@
{
__u32 hash[4];
+ net_secret_init();
memcpy(hash, daddr, 16);
md5_transform(hash, net_secret);
@@ -107,6 +124,7 @@
{
u32 hash[MD5_DIGEST_WORDS];
+ net_secret_init();
hash[0] = (__force u32)saddr;
hash[1] = (__force u32)daddr;
hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
@@ -121,6 +139,7 @@
{
u32 hash[MD5_DIGEST_WORDS];
+ net_secret_init();
hash[0] = (__force u32)saddr;
hash[1] = (__force u32)daddr;
hash[2] = (__force u32)dport ^ net_secret[14];
@@ -140,6 +159,7 @@
u32 hash[MD5_DIGEST_WORDS];
u64 seq;
+ net_secret_init();
hash[0] = (__force u32)saddr;
hash[1] = (__force u32)daddr;
hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
@@ -164,6 +184,7 @@
u64 seq;
u32 i;
+ net_secret_init();
memcpy(hash, saddr, 16);
for (i = 0; i < 4; i++)
secret[i] = net_secret[i] + daddr[i];