[PATCH] vsock: reject negative tv_usec in SO_VM_SOCKETS_CONNECT_TIMEOUT

[phind.uet@gmail.com]

From: Nguyen Dinh Phi <phind.uet@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.uet@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