usbredir: fix free call

Git-commit: 5e796671e6b8d5de4b0b423dce1b3eba144a92c9
References: bsc#1189145 CVE-2021-3682

data might point into the middle of a larger buffer, there is a separate
free_on_destroy pointer passed into bufp_alloc() to handle that.  It is
only used in the normal workflow though, not when dropping packets due
to the queue being full.  Fix that.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/491
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210722072756.647673-1-kraxel@redhat.com>
Signed-off-by: Jose R Ziviani <jose.ziviani@suse.com>

diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index dd779c45d2faa91eaeb107ca6398166509ade12e..7efff2b28766f92d03a0e1d1f8bf45b017b8ae5f 100644 (file)
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -463,7 +463,7 @@ static int bufp_alloc(USBRedirDevice *dev, uint8_t *data, uint16_t len,
     if (dev->endpoint[EP2I(ep)].bufpq_dropping_packets) {
         if (dev->endpoint[EP2I(ep)].bufpq_size >
                 dev->endpoint[EP2I(ep)].bufpq_target_size) {
-            free(data);
+            free(free_on_destroy);
             return -1;
         }
         dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 0;