From 7fb2fd4e25fc1fb10dcb30b5519de257cfeae84c Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 4 Jul 2018 12:33:34 +0300
Subject: [PATCH] vmci: type promotion bug in qp_host_get_user_memory()
Git-commit: 7fb2fd4e25fc1fb10dcb30b5519de257cfeae84c
Patch-mainline: v4.19-rc1
References: bsc#1105355

The problem is that if get_user_pages_fast() fails and returns a
negative error code, it gets type promoted to a high positive value and
treated as a success.

Fixes: 06164d2b72aa ("VMCI: queue pairs implementation.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/misc/vmw_vmci/vmci_queue_pair.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index 9ee47244a308..bd52f29b4a4e 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -668,7 +668,7 @@ static int qp_host_get_user_memory(u64 produce_uva,
 	retval = get_user_pages_fast((uintptr_t) produce_uva,
 				     produce_q->kernel_if->num_pages, 1,
 				     produce_q->kernel_if->u.h.header_page);
-	if (retval < produce_q->kernel_if->num_pages) {
+	if (retval < (int)produce_q->kernel_if->num_pages) {
 		pr_debug("get_user_pages_fast(produce) failed (retval=%d)",
 			retval);
 		qp_release_pages(produce_q->kernel_if->u.h.header_page,
@@ -680,7 +680,7 @@ static int qp_host_get_user_memory(u64 produce_uva,
 	retval = get_user_pages_fast((uintptr_t) consume_uva,
 				     consume_q->kernel_if->num_pages, 1,
 				     consume_q->kernel_if->u.h.header_page);
-	if (retval < consume_q->kernel_if->num_pages) {
+	if (retval < (int)consume_q->kernel_if->num_pages) {
 		pr_debug("get_user_pages_fast(consume) failed (retval=%d)",
 			retval);
 		qp_release_pages(consume_q->kernel_if->u.h.header_page,
-- 
2.18.0