usbredir: fix free call

[PATCH] usbredir: fix free call

Posted by Gerd Hoffmann 2 years, 9 months ago

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>
---
 hw/usb/redirect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index 4ec9326e0582..1ec909a63a80 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -476,7 +476,7 @@ 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;
-- 
2.31.1

Re: [PATCH] usbredir: fix free call

Posted by Marc-André Lureau 2 years, 9 months ago

Hi

On Thu, Jul 22, 2021 at 11:28 AM Gerd Hoffmann <kraxel@redhat.com> wrote:

> 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>

---
>  hw/usb/redirect.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
> index 4ec9326e0582..1ec909a63a80 100644
> --- a/hw/usb/redirect.c
> +++ b/hw/usb/redirect.c
> @@ -476,7 +476,7 @@ 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;
> --
> 2.31.1
>
>
>

-- 
Marc-André Lureau