[PATCH 1/1] Fix: vmw_vmci driver get_user_pages_fast error handling

[Mathieu Desnoyers]

Comparing a signed return value against an unsigned num_pages
field performs the comparison as "unsigned", and therefore mistakenly
considers get_user_pages_fast() errors as success.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
CC: Alexander Viro <v...@zeniv.linux.org.uk>
CC: George Zhang <georgezh...@vmware.com>
CC: Andy king <ack...@vmware.com>
CC: Dmitry Torokhov <d...@vmware.com>
CC: Greg Kroah-Hartman <gre...@linuxfoundation.org>
CC: linux-fsde...@vger.kernel.org
---
 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 8af5c2672f71..f71db848ce81 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -755,7 +755,7 @@ 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 < 0 || retval < 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,
@@ -767,7 +767,7 @@ 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 < 0 || retval < 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,
-- 
2.11.0