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authorLepton Wu <ytht.net@gmail.com>2018-12-11 11:12:55 -0800
committerDavid S. Miller <davem@davemloft.net>2018-12-14 14:40:19 -0800
commit8236b08cf50f85bbfaf48910a0b3ee68318b7c4b (patch)
tree69c8f9edba012677a29149a7c28fe57409298402
parent9c27369f4a1393452c17e8708c1b0beb8ac59501 (diff)
downloadlinux-8236b08cf50f85bbfaf48910a0b3ee68318b7c4b.tar.gz
VSOCK: bind to random port for VMADDR_PORT_ANY
The old code always starts from fixed port for VMADDR_PORT_ANY. Sometimes when VMM crashed, there is still orphaned vsock which is waiting for close timer, then it could cause connection time out for new started VM if they are trying to connect to same port with same guest cid since the new packets could hit that orphaned vsock. We could also fix this by doing more in vhost_vsock_reset_orphans, but any way, it should be better to start from a random local port instead of a fixed one. Signed-off-by: Lepton Wu <ytht.net@gmail.com> Reviewed-by: Jorgen Hansen <jhansen@vmware.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/vmw_vsock/af_vsock.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index ab27a287293577..43a1dec08825fe 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -107,6 +107,7 @@
#include <linux/mutex.h>
#include <linux/net.h>
#include <linux/poll.h>
+#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/smp.h>
#include <linux/socket.h>
@@ -504,9 +505,13 @@ out:
static int __vsock_bind_stream(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
- static u32 port = LAST_RESERVED_PORT + 1;
+ static u32 port = 0;
struct sockaddr_vm new_addr;
+ if (!port)
+ port = LAST_RESERVED_PORT + 1 +
+ prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
+
vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
if (addr->svm_port == VMADDR_PORT_ANY) {