Xen/gntdev: don't ignore kernel unmapping error

While working on XSA-361 and its follow-ups, I failed to spot another
place where the kernel mapping part of an operation was not treated the
same as the user space part. Detect and propagate errors and add a 2nd
pr_debug().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/c2513395-74dc-aea3-9192-fd265aa44e35@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 1e7f6b1c0c971a927cd3a6eec487b3fa48000982..fec1b6537166502e5b6dfedf058f83ffcd4e2e63 100644 (file)
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -381,6 +381,14 @@ static int __unmap_grant_pages(struct gntdev_grant_map *map, int offset,
                        map->unmap_ops[offset+i].handle,
                        map->unmap_ops[offset+i].status);
                map->unmap_ops[offset+i].handle = INVALID_GRANT_HANDLE;
+               if (use_ptemod) {
+                       if (map->kunmap_ops[offset+i].status)
+                               err = -EINVAL;
+                       pr_debug("kunmap handle=%u st=%d\n",
+                                map->kunmap_ops[offset+i].handle,
+                                map->kunmap_ops[offset+i].status);
+                       map->kunmap_ops[offset+i].handle = INVALID_GRANT_HANDLE;
+               }
        }
        return err;
 }