From: Christian Borntraeger <borntraeger@linux.ibm.com> stable inclusion from stable-v6.1.82~24 commit 5df3b81a567eb565029563f26f374ae3803a1dfc category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2GQ CVE: CVE-2023-52639 -------------------------------- [ Upstream commit fe752331d4b361d43cfd0b89534b4b2176057c32 ] Right now it is possible to see gmap->private being zero in kvm_s390_vsie_gmap_notifier resulting in a crash. This is due to the fact that we add gmap->private == kvm after creation: static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { [...] gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); if (IS_ERR(gmap)) return PTR_ERR(gmap); gmap->private = vcpu->kvm; Let children inherit the private field of the parent. Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Fixes: a3508fbe9dc6 ("KVM: s390: vsie: initial support for nested virtualization") Cc: <stable@vger.kernel.org> Cc: David Hildenbrand <david@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20231220125317.4258-1-borntraeger@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org> conflicts: arch/s390/kvm/vsie.c Signed-off-by: Cui GaoSheng <cuigaosheng1@huawei.com> --- arch/s390/kvm/vsie.c | 1 - arch/s390/mm/gmap.c | 1 + 2 files changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index a2b28cd1e3fe..93de43a32cfb 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -933,7 +933,6 @@ static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); if (IS_ERR(gmap)) return PTR_ERR(gmap); - gmap->private = vcpu->kvm; WRITE_ONCE(vsie_page->gmap, gmap); return 0; } diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 911c7ded35f1..df2de0b9822b 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -1652,6 +1652,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce, return ERR_PTR(-ENOMEM); new->mm = parent->mm; new->parent = gmap_get(parent); + new->private = parent->private; new->orig_asce = asce; new->edat_level = edat_level; new->initialized = false; -- 2.34.1