Commit f2ca45b50d42 for kernel
commit f2ca45b50d4216c9cc7ffabf50d9ad1932209251
Author: Hyunwoo Kim <imv4bel@gmail.com>
Date: Wed Jun 3 21:09:33 2026 +0900
KVM: arm64: Take the SRCU lock for page table walks in fault injection and AT emulation
walk_s1() and kvm_walk_nested_s2() expect to be called while holding
kvm->srcu to guard against memslot changes. While this is generally
the case, __kvm_at_s12() and __kvm_find_s1_desc_level() call into the
respective walkers without taking kvm->srcu.
Fix by acquiring kvm->srcu prior to the table walk in both instances.
Cc: stable@vger.kernel.org
Fixes: 50f77dc87f13 ("KVM: arm64: Populate level on S1PTW SEA injection")
Fixes: be04cebf3e78 ("KVM: arm64: nv: Add emulation of AT S12E{0,1}{R,W}")
Suggested-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/aiAZfdeyanIvP8SD@v4bel
Signed-off-by: Marc Zyngier <maz@kernel.org>
diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index 9f8f0ae8e86e..889c2c15d7bd 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -1569,7 +1569,8 @@ int __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
/* Do the stage-2 translation */
ipa = (par & GENMASK_ULL(47, 12)) | (vaddr & GENMASK_ULL(11, 0));
out.esr = 0;
- ret = kvm_walk_nested_s2(vcpu, ipa, &out);
+ scoped_guard(srcu, &vcpu->kvm->srcu)
+ ret = kvm_walk_nested_s2(vcpu, ipa, &out);
if (ret < 0)
return ret;
@@ -1665,7 +1666,8 @@ int __kvm_find_s1_desc_level(struct kvm_vcpu *vcpu, u64 va, u64 ipa, int *level)
}
/* Walk the guest's PT, looking for a match along the way */
- ret = walk_s1(vcpu, &wi, &wr, va);
+ scoped_guard(srcu, &vcpu->kvm->srcu)
+ ret = walk_s1(vcpu, &wi, &wr, va);
switch (ret) {
case -EINTR:
/* We interrupted the walk on a match, return the level */