mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-22 10:31:08 +00:00
Code Issues Releases Wiki Activity

KVM: arm64: Prevent unconditional donation of unmapped regions from the host

Browse source 
Since host stage-2 mappings are created lazily, we cannot rely solely on
the pte in order to recover the target physical address when checking a
host-initiated memory transition as this permits donation of unmapped
regions corresponding to MMIO or "no-map" memory.

Instead of inspecting the pte, move the addr_is_allowed_memory() check
into the host callback function where it is passed the physical address
directly from the walker.

Cc: Quentin Perret <qperret@google.com>
Fixes: e82edcc75c ("KVM: arm64: Implement do_share() helper for sharing memory")
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230518095844.1178-1-will@kernel.org
This commit is contained in:
Will Deacon 2023-05-18 10:58:44 +01:00 committed by Marc Zyngier
parent 6254873226
commit 09cce60bdd
1 changed files with 7 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
arch/arm64/kvm/hyp/nvhe/mem_protect.c
View file

@ -575,7 +575,7 @@ struct pkvm_mem_donation {
struct check_walk_data {
enum pkvm_page_state desired;
enum pkvm_page_state (*get_page_state)(kvm_pte_t pte);
enum pkvm_page_state (*get_page_state)(kvm_pte_t pte, u64 addr);
};
static int __check_page_state_visitor(const struct kvm_pgtable_visit_ctx *ctx,
@ -583,10 +583,7 @@ static int __check_page_state_visitor(const struct kvm_pgtable_visit_ctx *ctx,
{
struct check_walk_data *d = ctx->arg;
if (kvm_pte_valid(ctx->old) && !addr_is_allowed_memory(kvm_pte_to_phys(ctx->old)))
return -EINVAL;
return d->get_page_state(ctx->old) == d->desired ? 0 : -EPERM;
return d->get_page_state(ctx->old, ctx->addr) == d->desired ? 0 : -EPERM;
}
static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size,
@ -601,8 +598,11 @@ static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size,
return kvm_pgtable_walk(pgt, addr, size, &walker);
}
static enum pkvm_page_state host_get_page_state(kvm_pte_t pte)
static enum pkvm_page_state host_get_page_state(kvm_pte_t pte, u64 addr)
{
if (!addr_is_allowed_memory(addr))
return PKVM_NOPAGE;
if (!kvm_pte_valid(pte) && pte)
return PKVM_NOPAGE;
@ -709,7 +709,7 @@ static int host_complete_donation(u64 addr, const struct pkvm_mem_transition *tx
return host_stage2_set_owner_locked(addr, size, host_id);
}
static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte)
static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte, u64 addr)
{
if (!kvm_pte_valid(pte))
return PKVM_NOPAGE;