From 90ca6333fd65f318c47bff425e1ea36c0a5539f6 Mon Sep 17 00:00:00 2001 From: Alex Dewar Date: Tue, 25 Aug 2020 17:45:18 +0100 Subject: [PATCH] VMCI: check return value of get_user_pages_fast() for errors In a couple of places in qp_host_get_user_memory(), get_user_pages_fast() is called without properly checking for errors. If e.g. -EFAULT is returned, this negative value will then be passed on to qp_release_pages(), which expects a u64 as input. Fix this by only calling qp_release_pages() when we have a positive number returned. Fixes: 06164d2b72aa ("VMCI: queue pairs implementation.") Signed-off-by: Alex Dewar Link: https://lore.kernel.org/r/20200825164522.412392-1-alex.dewar90@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/vmw_vmci/vmci_queue_pair.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c index 8531ae7..c490658 100644 --- a/drivers/misc/vmw_vmci/vmci_queue_pair.c +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c @@ -657,8 +657,9 @@ static int qp_host_get_user_memory(u64 produce_uva, 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, - retval, false); + if (retval > 0) + qp_release_pages(produce_q->kernel_if->u.h.header_page, + retval, false); err = VMCI_ERROR_NO_MEM; goto out; } @@ -670,8 +671,9 @@ static int qp_host_get_user_memory(u64 produce_uva, 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, - retval, false); + if (retval > 0) + qp_release_pages(consume_q->kernel_if->u.h.header_page, + retval, false); qp_release_pages(produce_q->kernel_if->u.h.header_page, produce_q->kernel_if->num_pages, false); err = VMCI_ERROR_NO_MEM; -- 2.7.4