[PATCH] vsock: reject negative tv_usec in SO_VM_SOCKETS_CONNECT_TIMEOUT

[phind . uet]

From: Nguyen Dinh Phi <phind....@gmail.com>

The timeval validation checks tv_usec < USEC_PER_SEC but not
tv_usec >= 0, so a negative tv_usec makes the timeout computation
wrap into a bogus value, later tripping "schedule_timeout: wrong
timeout value" instead of being rejected.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")

Signed-off-by: Nguyen Dinh Phi <phind....@gmail.com>
---
 net/vmw_vsock/af_vsock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index d0508887a2fb..1d7d53542724 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -2156,7 +2156,8 @@ static int vsock_connectible_setsockopt(struct socket 
*sock,
                                             optname == 
SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD);
                if (err)
                        break;
-               if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
+               if (tv.tv_sec >= 0 && tv.tv_usec >= 0 &&
+                   tv.tv_usec < USEC_PER_SEC &&
                    tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
                        vsk->connect_timeout = tv.tv_sec * HZ +
                                DIV_ROUND_UP((unsigned long)tv.tv_usec, 
(USEC_PER_SEC / HZ));
-- 
2.43.0