diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 07e2ca5ccb8062ffc1791ee09b2e62a338e1fd13..6aaf1bf68028e14e52738a253c4080383edc9165 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4497,6 +4497,17 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
 
 	vmx_switch_vmcs(vcpu, &vmx->vmcs01);
 
+	/*
+	 * If IBRS is advertised to the vCPU, KVM must flush the indirect
+	 * branch predictors when transitioning from L2 to L1, as L1 expects
+	 * hardware (KVM in this case) to provide separate predictor modes.
+	 * Bare metal isolates VMX root (host) from VMX non-root (guest), but
+	 * doesn't isolate different VMCSs, i.e. in this case, doesn't provide
+	 * separate modes for L2 vs L1.
+	 */
+	if (guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
+		indirect_branch_prediction_barrier();
+
 	/* Update any VMCS fields that might have changed while L2 ran */
 	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
 	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cf95e490b8e78ab1cf0a0e846dbccd3bfdb8c283..58d453b6667742379d027976511c78450fd65934 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1431,8 +1431,10 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu,
 
 		/*
 		 * No indirect branch prediction barrier needed when switching
-		 * the active VMCS within a guest, e.g. on nested VM-Enter.
-		 * The L1 VMM can protect itself with retpolines, IBPB or IBRS.
+		 * the active VMCS within a vCPU, unless IBRS is advertised to
+		 * the vCPU.  To minimize the number of IBPBs executed, KVM
+		 * performs IBPB on nested VM-Exit (a single nested transition
+		 * may switch the active VMCS multiple times).
 		 */
 		if (!buddy || WARN_ON_ONCE(buddy->vmcs != prev))
 			indirect_branch_prediction_barrier();
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 95ca4f934d283db8489befafc90da6b762634e90..a77ed66425f27cee5a0875baa02d8125e7fc8f5f 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -212,7 +212,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 		mm = alloc->vma_vm_mm;
 
 	if (mm) {
-		mmap_read_lock(mm);
+		mmap_write_lock(mm);
 		vma = alloc->vma;
 	}
 
@@ -270,7 +270,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 		trace_binder_alloc_page_end(alloc, index);
 	}
 	if (mm) {
-		mmap_read_unlock(mm);
+		mmap_write_unlock(mm);
 		mmput(mm);
 	}
 	return 0;
@@ -303,7 +303,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 	}
 err_no_vma:
 	if (mm) {
-		mmap_read_unlock(mm);
+		mmap_write_unlock(mm);
 		mmput(mm);
 	}
 	return vma ? -ENOMEM : -ESRCH;