[PATCH] xl: properly dispose of libxl_dominfo struct instances

[PATCH] xl: properly dispose of libxl_dominfo struct instances

[Jan Beulich]

The ssid_label field requires separate freeing; make sure to call
libxl_dominfo_dispose(). And then, for good measure, also
libxl_dominfo_init().

Coverity-ID: 1638727
Coverity-ID: 1638728
Fixes: c458c404da16 ("xl: use libxl_domain_info to get the uuid in printf_info")
Fixes: 48dab9767d2e ("tools/xl: use libxl_domain_info to get domain type for vcpu-pin")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
I wasn't quite sure about use of libxl_dominfo_init(): vcpuset(), for
example, doesn't call it.

--- a/tools/xl/xl_sxp.c
+++ b/tools/xl/xl_sxp.c
@@ -45,8 +45,10 @@ void printf_info_sexp(int domid, libxl_d
     /* retrieve the UUID from dominfo, since it is probably generated
      * during parsing and thus does not match the real one
      */
+    libxl_dominfo_init(&info);
     if (libxl_domain_info(ctx, &info, domid) == 0) {
         fprintf(fh, "\t(uuid " LIBXL_UUID_FMT ")\n", LIBXL_UUID_BYTES(info.uuid));
+        libxl_dominfo_dispose(&info);
     } else {
         fprintf(fh, "\t(uuid <unknown>)\n");
     }
--- a/tools/xl/xl_vcpu.c
+++ b/tools/xl/xl_vcpu.c
@@ -286,6 +286,8 @@ int main_vcpupin(int argc, char **argv)
     if (!ignore_masks && hard) {
         libxl_dominfo dominfo;
 
+        libxl_dominfo_init(&dominfo);
+
         if (libxl_domain_info(ctx, &dominfo, domid)) {
             fprintf(stderr, "Could not get domain info\n");
             goto out;
@@ -293,6 +295,8 @@ int main_vcpupin(int argc, char **argv)
 
         /* HVM and PVH domains use the same global affinity mask */
         apply_global_affinity_masks(dominfo.domain_type, hard, 1);
+
+        libxl_dominfo_dispose(&dominfo);
     }
 
     if (force) {

Re: [PATCH] xl: properly dispose of libxl_dominfo struct instances

[Andrew Cooper]

On 14/01/2025 8:12 am, Jan Beulich wrote:
> The ssid_label field requires separate freeing; make sure to call
> libxl_dominfo_dispose(). And then, for good measure, also
> libxl_dominfo_init().
>
> Coverity-ID: 1638727
> Coverity-ID: 1638728
> Fixes: c458c404da16 ("xl: use libxl_domain_info to get the uuid in printf_info")
> Fixes: 48dab9767d2e ("tools/xl: use libxl_domain_info to get domain type for vcpu-pin")
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> I wasn't quite sure about use of libxl_dominfo_init(): vcpuset(), for
> example, doesn't call it.

It's a written requirement (somewhere) that *_init() and *_dispose() do
get called.

Except everyone's lazy with them and plenty of scenarios function
without, which is why it's often Coverity telling us about it (but only
for the instances where there's a real malloc()/free() gone missing).

I expect it would be better to extend this patch to fix up vcpuset()
too.  The changes so far LGTM.

~Andrew

Re: [PATCH] xl: properly dispose of libxl_dominfo struct instances

[Oleksii Kurochko]

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On 1/14/25 9:12 AM, Jan Beulich wrote:
> The ssid_label field requires separate freeing; make sure to call
> libxl_dominfo_dispose(). And then, for good measure, also
> libxl_dominfo_init().
>
> Coverity-ID: 1638727
> Coverity-ID: 1638728
> Fixes: c458c404da16 ("xl: use libxl_domain_info to get the uuid in printf_info")
> Fixes: 48dab9767d2e ("tools/xl: use libxl_domain_info to get domain type for vcpu-pin")
> Signed-off-by: Jan Beulich<jbeulich@suse.com>

Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>

Thanks.

~ Oleksii

> ---
> I wasn't quite sure about use of libxl_dominfo_init(): vcpuset(), for
> example, doesn't call it.
>
> --- a/tools/xl/xl_sxp.c
> +++ b/tools/xl/xl_sxp.c
> @@ -45,8 +45,10 @@ void printf_info_sexp(int domid, libxl_d
>       /* retrieve the UUID from dominfo, since it is probably generated
>        * during parsing and thus does not match the real one
>        */
> +    libxl_dominfo_init(&info);
>       if (libxl_domain_info(ctx, &info, domid) == 0) {
>           fprintf(fh, "\t(uuid " LIBXL_UUID_FMT ")\n", LIBXL_UUID_BYTES(info.uuid));
> +        libxl_dominfo_dispose(&info);
>       } else {
>           fprintf(fh, "\t(uuid <unknown>)\n");
>       }
> --- a/tools/xl/xl_vcpu.c
> +++ b/tools/xl/xl_vcpu.c
> @@ -286,6 +286,8 @@ int main_vcpupin(int argc, char **argv)
>       if (!ignore_masks && hard) {
>           libxl_dominfo dominfo;
>   
> +        libxl_dominfo_init(&dominfo);
> +
>           if (libxl_domain_info(ctx, &dominfo, domid)) {
>               fprintf(stderr, "Could not get domain info\n");
>               goto out;
> @@ -293,6 +295,8 @@ int main_vcpupin(int argc, char **argv)
>   
>           /* HVM and PVH domains use the same global affinity mask */
>           apply_global_affinity_masks(dominfo.domain_type, hard, 1);
> +
> +        libxl_dominfo_dispose(&dominfo);
>       }
>   
>       if (force) {

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