ipv6: tcp: fix panic in SYN processing

commit c16a98ed91597b40b22b540c6517103497ef8e74 upstream.

commit 72a3effaf633bc ([NET]: Size listen hash tables using backlog
hint) added a bug allowing inet6_synq_hash() to return an out of bound
array index, because of u16 overflow.

Bug can happen if system admins set net.core.somaxconn &
net.ipv4.tcp_max_syn_backlog sysctls to values greater than 65536

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index 8a58e8cf6646b2bbe886bde46cdb72c7b548822a..aea323c042220ab26def2d5248baf9d047042186 100644 (file)
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -85,7 +85,7 @@ struct dst_entry *inet6_csk_route_req(struct sock *sk,
  * request_sock (formerly open request) hash tables.
  */
 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
-                          const u32 rnd, const u16 synq_hsize)
+                          const u32 rnd, const u32 synq_hsize)
 {
        u32 c;