From mboxrd@z Thu Jan 1 00:00:00 1970 From: hejianet@gmail.com (Jia He) Date: Fri, 18 May 2018 17:27:10 +0800 Subject: [PATCH v2 2/2] KVM: arm/arm64: harden unmap_stage2_ptes in case end is not PAGE_SIZE aligned In-Reply-To: <1526635630-18917-1-git-send-email-hejianet@gmail.com> References: <1526635630-18917-1-git-send-email-hejianet@gmail.com> Message-ID: <1526635630-18917-2-git-send-email-hejianet@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org If it passes addr=0x202920000,size=0xfe00 to unmap_stage2_range-> ...->unmap_stage2_ptes, unmap_stage2_ptes will get addr=0x202920000, end=0x20292fe00. After first while loop addr=0x202930000, end=0x20292fe00, then addr!=end. Thus it will touch another pages by put_pages() in the 2nd loop. This patch fixes it by hardening the break condition of while loop. Signed-off-by: jia.he at hxt-semitech.com --- v2: newly added virt/kvm/arm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 8dac311..45cd040 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -217,7 +217,7 @@ static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd, put_page(virt_to_page(pte)); } - } while (pte++, addr += PAGE_SIZE, addr != end); + } while (pte++, addr += PAGE_SIZE, addr < end); if (stage2_pte_table_empty(start_pte)) clear_stage2_pmd_entry(kvm, pmd, start_addr); -- 1.8.3.1