From: Christian Borntraeger borntraeger@linux.ibm.com

stable inclusion from stable-v6.1.82 commit 5df3b81a567eb565029563f26f374ae3803a1dfc category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2GQ CVE: CVE-2023-52639

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ 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 3fbf7081c000..ebfc4386d140 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -1197,7 +1197,6 @@ 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 03e561608eed..ac74cb6206a1 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -1663,6 +1663,7 @@ 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;