From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Sasha Levin Subject: [PATCH 4.14 004/137] vmci: type promotion bug in qp_host_get_user_memory() Date: Tue, 2 Oct 2018 06:23:25 -0700 Message-Id: <20181002132458.704293369@linuxfoundation.org> In-Reply-To: <20181002132458.446916963@linuxfoundation.org> References: <20181002132458.446916963@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/misc/vmw_vmci/vmci_queue_pair.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- 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 p 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, @@ -767,7 +767,7 @@ static int qp_host_get_user_memory(u64 p 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,