-stable review patch. If anyone has any objections, please let us know. --------------------- From: Andrea Arcangeli upstream commit: 4539b35881ae9664b0e2953438dd83f5ee02c0b4 When kvm emulates an invlpg instruction, it can drop a shadow pte, but leaves the guest tlbs intact. This can cause memory corruption when swapping out. Without this the other cpu can still write to a freed host physical page. tlb smp flush must happen if rmap_remove is called always before mmu_lock is released because the VM will take the mmu_lock before it can finally add the page to the freelist after swapout. mmu notifier makes it safe to flush the tlb after freeing the page (otherwise it would never be safe) so we can do a single flush for multiple sptes invalidated. Cc: stable@kernel.org Signed-off-by: Andrea Arcangeli Acked-by: Marcelo Tosatti Signed-off-by: Avi Kivity [mtosatti: backport to 2.6.29] Signed-off-by: Chris Wright --- arch/x86/kvm/paging_tmpl.h | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -476,16 +476,20 @@ static int FNAME(shadow_invlpg_entry)(st if (level == PT_PAGE_TABLE_LEVEL || ((level == PT_DIRECTORY_LEVEL) && is_large_pte(*sptep))) { struct kvm_mmu_page *sp = page_header(__pa(sptep)); + int need_flush = 0; sw->pte_gpa = (sp->gfn << PAGE_SHIFT); sw->pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t); if (is_shadow_present_pte(*sptep)) { + need_flush = 1; rmap_remove(vcpu->kvm, sptep); if (is_large_pte(*sptep)) --vcpu->kvm->stat.lpages; } set_shadow_pte(sptep, shadow_trap_nonpresent_pte); + if (need_flush) + kvm_flush_remote_tlbs(vcpu->kvm); return 1; } if (!is_shadow_present_pte(*sptep)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/