| Message ID | 20241115083440.2236669-1-clg@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] vfio/container: Fix container object destruction | expand |
>-----Original Message----- >From: Cédric Le Goater <clg@redhat.com> >Sent: Friday, November 15, 2024 4:35 PM >Subject: [PATCH v2] vfio/container: Fix container object destruction > >When commit 96b7af4388b3 intoduced a .instance_finalize() handler, >it did not take into account that the container was not necessarily >inserted into the container list of the address space. Hence, if >the container object is destroyed, by calling object_unref() for >example, before vfio_address_space_insert() is called, QEMU may >crash when removing the container from the list as done in >vfio_container_instance_finalize(). This was seen with an SEV-SNP >guest for which discarding of RAM fails. > >To resolve this issue, use the safe version of QLIST_REMOVE(). > >Cc: Zhenzhong Duan <zhenzhong.duan@intel.com> >Cc: Eric Auger <eric.auger@redhat.com> >Fixes: 96b7af4388b3 ("vfio/container: Move vfio_container_destroy() to an >instance_finalize() handler") >Signed-off-by: Cédric Le Goater <clg@redhat.com> Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Thanks Zhenzhong
diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c index 809b15767425a48f2404b08fc409ee5684af2094..6f86c37d971ec38426dacd471bca837c0d0df806 100644 --- a/hw/vfio/container-base.c +++ b/hw/vfio/container-base.c @@ -103,7 +103,7 @@ static void vfio_container_instance_finalize(Object *obj) VFIOContainerBase *bcontainer = VFIO_IOMMU(obj); VFIOGuestIOMMU *giommu, *tmp; - QLIST_REMOVE(bcontainer, next); + QLIST_SAFE_REMOVE(bcontainer, next); QLIST_FOREACH_SAFE(giommu, &bcontainer->giommu_list, giommu_next, tmp) { memory_region_unregister_iommu_notifier(
When commit 96b7af4388b3 intoduced a .instance_finalize() handler, it did not take into account that the container was not necessarily inserted into the container list of the address space. Hence, if the container object is destroyed, by calling object_unref() for example, before vfio_address_space_insert() is called, QEMU may crash when removing the container from the list as done in vfio_container_instance_finalize(). This was seen with an SEV-SNP guest for which discarding of RAM fails. To resolve this issue, use the safe version of QLIST_REMOVE(). Cc: Zhenzhong Duan <zhenzhong.duan@intel.com> Cc: Eric Auger <eric.auger@redhat.com> Fixes: 96b7af4388b3 ("vfio/container: Move vfio_container_destroy() to an instance_finalize() handler") Signed-off-by: Cédric Le Goater <clg@redhat.com> --- Changes in v2: - use the safe version of QLIST_REMOVE() instead of calling vfio_address_space_insert() earlier. hw/vfio/container-base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)