Zero out the user provided memory in order to avoid passing random
pointers to VIR_FREE later.

Signed-off-by: Ilias Stamatis <stamatis.iliass@gmail.com>
---
 src/test/test_driver.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index 7c58d2c8ce..8ee1f0cad6 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -3275,6 +3275,7 @@ static int testDomainGetDiskErrors(virDomainPtr dom,
     virDomainObjPtr vm = NULL;
     int ret = -1;
     size_t i;
+    size_t nerrors;

     virCheckFlags(0, -1);

@@ -3284,8 +3285,13 @@ static int testDomainGetDiskErrors(virDomainPtr dom,
     if (virDomainObjCheckActive(vm) < 0)
         goto cleanup;

+    nerrors = MIN(vm->def->ndisks, maxerrors);
+
     if (errors) {
-        for (i = 0; i < MIN(vm->def->ndisks, maxerrors); i++) {
+        /* sanitize input */
+        memset(errors, 0, sizeof(virDomainDiskError) * nerrors);
+
+        for (i = 0; i < nerrors; i++) {
             if (VIR_STRDUP(errors[i].disk, vm->def->disks[i]->dst) < 0)
                 goto cleanup;
             errors[i].error = (i % (VIR_DOMAIN_DISK_ERROR_LAST - 1)) + 1;
@@ -3297,7 +3303,7 @@ static int testDomainGetDiskErrors(virDomainPtr dom,

  cleanup:
     if (ret < 0) {
-        for (i = 0; i < MIN(vm->def->ndisks, maxerrors); i++)
+        for (i = 0; i < nerrors; i++)
             VIR_FREE(errors[i].disk);
     }
     virDomainObjEndAPI(&vm);
--
2.22.0

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list

On Thu, Jul 04, 2019 at 01:31:34PM +0200, Ilias Stamatis wrote:
> Zero out the user provided memory in order to avoid passing random
> pointers to VIR_FREE later.
> 
> Signed-off-by: Ilias Stamatis <stamatis.iliass@gmail.com>
> ---
>  src/test/test_driver.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/src/test/test_driver.c b/src/test/test_driver.c
> index 7c58d2c8ce..8ee1f0cad6 100644
> --- a/src/test/test_driver.c
> +++ b/src/test/test_driver.c
> @@ -3275,6 +3275,7 @@ static int testDomainGetDiskErrors(virDomainPtr dom,
>      virDomainObjPtr vm = NULL;
>      int ret = -1;
>      size_t i;
> +    size_t nerrors;

Not initialized...

> 
>      virCheckFlags(0, -1);
> 
> @@ -3284,8 +3285,13 @@ static int testDomainGetDiskErrors(virDomainPtr dom,
>      if (virDomainObjCheckActive(vm) < 0)
>          goto cleanup;

...error path jumps over the initialization...

> 
> +    nerrors = MIN(vm->def->ndisks, maxerrors);
> +
>      if (errors) {
> -        for (i = 0; i < MIN(vm->def->ndisks, maxerrors); i++) {
> +        /* sanitize input */
> +        memset(errors, 0, sizeof(virDomainDiskError) * nerrors);
> +
> +        for (i = 0; i < nerrors; i++) {
>              if (VIR_STRDUP(errors[i].disk, vm->def->disks[i]->dst) < 0)
>                  goto cleanup;
>              errors[i].error = (i % (VIR_DOMAIN_DISK_ERROR_LAST - 1)) + 1;
> @@ -3297,7 +3303,7 @@ static int testDomainGetDiskErrors(virDomainPtr dom,
> 
>   cleanup:
>      if (ret < 0) {
> -        for (i = 0; i < MIN(vm->def->ndisks, maxerrors); i++)
> +        for (i = 0; i < nerrors; i++)

...loops with limit set to an uninitialized value :-)


../../src/test/test_driver.c: In function 'testDomainGetDiskErrors':
../../src/test/test_driver.c:3306:9: error: 'nerrors' may be used uninitialized in this function [-Werror=maybe-uninitialized]
         for (i = 0; i < nerrors; i++)
         ^~~
cc1: all warnings being treated as errors

>              VIR_FREE(errors[i].disk);
>      }
>      virDomainObjEndAPI(&vm);

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list

On Thu, Jul 04, 2019 at 01:31:34PM +0200, Ilias Stamatis wrote:
> Zero out the user provided memory in order to avoid passing random

"to a avoid potentially freeing uninitialized memory"

> pointers to VIR_FREE later.
>
> Signed-off-by: Ilias Stamatis <stamatis.iliass@gmail.com>
> ---
Reviewed-by: Erik Skultety <eskultet@redhat.com>

--
libvir-list mailing list
libvir-list@redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list