1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 3c5507313606..051639c09f72 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -12,6 +12,7 @@
 
 #include <linux/atomic.h>
 #include <linux/compat.h>
+#include <linux/cred.h>
 #include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/hid.h>
@@ -722,6 +723,17 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
 
         switch (uhid->input_buf.type) {
         case UHID_CREATE:
+                /*
+                 * 'struct uhid_create_req' contains a __user pointer which is
+                 * copied from, so it's unsafe to allow this with elevated
+                 * privileges (e.g. from a setuid binary) or via kernel_write().
+                 */
+                if (file->f_cred != current_cred() || uaccess_kernel()) {
+                        pr_err_once("UHID_CREATE from different security context by process %d (%s), this is not allowed.\n",
+                                    task_tgid_vnr(current), current->comm);
+                        ret = -EACCES;
+                        goto unlock;
+                }
                 ret = uhid_dev_create(uhid, &uhid->input_buf);
                 break;
         case UHID_CREATE2: