[PATCH] xen/privcmd: Use memdup_array_user() in alloc_ioreq()

[Markus Elfring <Markus.Elfring@xxxxxx>]

From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Date: Sun, 28 Jan 2024 17:50:43 +0100

* The function “memdup_array_user” was added with the
  commit 313ebe47d75558511aa1237b6e35c663b5c0ec6f ("string.h: add
  array-wrappers for (v)memdup_user()").
  Thus use it accordingly.

  This issue was detected by using the Coccinelle software.

* Delete a label which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
---
 drivers/xen/privcmd.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 35b6e306026a..2c8f6d047c11 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -1223,18 +1223,13 @@ struct privcmd_kernel_ioreq *alloc_ioreq(struct 
privcmd_ioeventfd *ioeventfd)
        kioreq->ioreq = (struct ioreq *)(page_to_virt(pages[0]));
        mmap_write_unlock(mm);

-       size = sizeof(*ports) * kioreq->vcpus;
-       ports = kzalloc(size, GFP_KERNEL);
-       if (!ports) {
-               ret = -ENOMEM;
+       ports = memdup_array_user(u64_to_user_ptr(ioeventfd->ports),
+                                 kioreq->vcpus, sizeof(*ports));
+       if (IS_ERR(ports) {
+               ret = PTR_ERR(ports);
                goto error_kfree;
        }

-       if (copy_from_user(ports, u64_to_user_ptr(ioeventfd->ports), size)) {
-               ret = -EFAULT;
-               goto error_kfree_ports;
-       }
-
        for (i = 0; i < kioreq->vcpus; i++) {
                kioreq->ports[i].vcpu = i;
                kioreq->ports[i].port = ports[i];
@@ -1256,7 +1251,7 @@ struct privcmd_kernel_ioreq *alloc_ioreq(struct 
privcmd_ioeventfd *ioeventfd)
 error_unbind:
        while (--i >= 0)
                unbind_from_irqhandler(irq_from_evtchn(ports[i]), 
&kioreq->ports[i]);
-error_kfree_ports:
+
        kfree(ports);
 error_kfree:
        kfree(kioreq);
--
2.43.0