diff mbox series

[for-3.1,v3,2/2] usb-mtp: outlaw slashes in filenames

Message ID 20181203101045.27976-3-kraxel@redhat.com (mailing list archive)
State New, archived
Headers show
Series usb-mtp: two bugfixes (one security fix). | expand

Commit Message

Gerd Hoffmann Dec. 3, 2018, 10:10 a.m. UTC 
Slash is unix directory separator, so they are not allowed in filenames.
Note this also stops the classic escape via "../".

Fixes: CVE-2018-16867
Reported-by: Michael Hanselmann <public@hansmi.ch>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/usb/dev-mtp.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox series

Patch

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 0f6a9702ef..100b7171f4 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -1719,6 +1719,12 @@  static void usb_mtp_write_metadata(MTPState *s)
 
     filename = utf16_to_str(dataset->length, dataset->filename);
 
+    if (strchr(filename, '/')) {
+        usb_mtp_queue_result(s, RES_PARAMETER_NOT_SUPPORTED, d->trans,
+                             0, 0, 0, 0);
+        return;
+    }
+
     o = usb_mtp_object_lookup_name(p, filename, dataset->length);
     if (o != NULL) {
         next_handle = o->handle;