hw/s390x/ccw-device: Fix memory leak in loadparm setter

[PATCH] hw/s390x/ccw-device: Fix memory leak in loadparm setter

Posted by Kevin Wolf 4 months, 3 weeks ago

Commit bdf12f2a fixed the setter for the "loadparm" machine property,
which gets a string from a visitor, passes it to s390_ipl_fmt_loadparm()
and then forgot to free it. It left another instance of the same problem
unfixed in the "loadparm" device property. Fix it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/s390x/ccw-device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/s390x/ccw-device.c b/hw/s390x/ccw-device.c
index 19c2238f76..8be1813b9e 100644
--- a/hw/s390x/ccw-device.c
+++ b/hw/s390x/ccw-device.c
@@ -57,7 +57,7 @@ static void ccw_device_set_loadparm(Object *obj, Visitor *v,
                                  Error **errp)
 {
     CcwDevice *dev = CCW_DEVICE(obj);
-    char *val;
+    g_autofree char *val = NULL;
     int index;
 
     index = object_property_get_int(obj, "bootindex", NULL);
-- 
2.49.0

Re: [PATCH] hw/s390x/ccw-device: Fix memory leak in loadparm setter

Posted by Halil Pasic 4 months, 3 weeks ago

On Wed, 25 Jun 2025 10:27:51 +0200
Kevin Wolf <kwolf@redhat.com> wrote:

> Commit bdf12f2a fixed the setter for the "loadparm" machine property,
> which gets a string from a visitor, passes it to s390_ipl_fmt_loadparm()
> and then forgot to free it. It left another instance of the same problem
> unfixed in the "loadparm" device property. Fix it.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Reviewed-by: Halil Pasic <pasic@linux.ibm.com>

Re: [PATCH] hw/s390x/ccw-device: Fix memory leak in loadparm setter

Posted by Thomas Huth 4 months, 3 weeks ago

On 25/06/2025 10.27, Kevin Wolf wrote:
> Commit bdf12f2a fixed the setter for the "loadparm" machine property,
> which gets a string from a visitor, passes it to s390_ipl_fmt_loadparm()
> and then forgot to free it. It left another instance of the same problem
> unfixed in the "loadparm" device property. Fix it.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   hw/s390x/ccw-device.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/ccw-device.c b/hw/s390x/ccw-device.c
> index 19c2238f76..8be1813b9e 100644
> --- a/hw/s390x/ccw-device.c
> +++ b/hw/s390x/ccw-device.c
> @@ -57,7 +57,7 @@ static void ccw_device_set_loadparm(Object *obj, Visitor *v,
>                                    Error **errp)
>   {
>       CcwDevice *dev = CCW_DEVICE(obj);
> -    char *val;
> +    g_autofree char *val = NULL;
>       int index;

I was able to reproduce the leak with a command line like this:

valgrind --trace-children=yes --track-origins=yes --leak-check=full \
  --show-leak-kinds=definite ./qemu-system-s390x -nographic -accel kvm \
   -drive if=none,file=/tmp/disk0.qcow2,format=qcow2,id=drive_image1 \
   -device virtio-blk-ccw,drive="drive_image1",bootindex=0,loadparm=4 \
   -device virtio-scsi-ccw

And I can confirm that your patch fixes the issue, thank you!

Tested-by: Thomas Huth <thuth@redhat.com>

I'll queue it for my next pull request.

Re: [PATCH] hw/s390x/ccw-device: Fix memory leak in loadparm setter

Posted by Eric Farman 4 months, 3 weeks ago

On Wed, 2025-06-25 at 10:27 +0200, Kevin Wolf wrote:
> Commit bdf12f2a fixed the setter for the "loadparm" machine property,
> which gets a string from a visitor, passes it to s390_ipl_fmt_loadparm()
> and then forgot to free it. It left another instance of the same problem
> unfixed in the "loadparm" device property. Fix it.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  hw/s390x/ccw-device.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Eric Farman <farman@linux.ibm.com>