HID: Add quirk for HP X1200 PIXART OEM mouse

[mirror_ubuntu-bionic-kernel.git] / drivers / hid / uhid.c

diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 6f819f144cb4f063a4962a202dc8b472c921a235..6f67d73b184e52814342834c965f181244f6b43a 100644 (file)
--- 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: