From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Dan Carpenter , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 4.14 04/87] vmci: type promotion bug in qp_host_get_user_memory() Date: Mon, 17 Sep 2018 03:02:26 +0000 Message-ID: <20180917030220.245686-4-alexander.levin@microsoft.com> References: <20180917030220.245686-1-alexander.levin@microsoft.com> In-Reply-To: <20180917030220.245686-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Dan Carpenter [ Upstream commit 7fb2fd4e25fc1fb10dcb30b5519de257cfeae84c ] 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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- 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_vmc= i/vmci_queue_pair.c index 8af5c2672f71..b4570d5c1fe7 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 =3D 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=3D%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 =3D 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=3D%d)", retval); qp_release_pages(consume_q->kernel_if->u.h.header_page, --=20 2.17.1