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authorChristoffer Dall <christoffer.dall@linaro.org>2013-08-06 13:50:54 -0700
committerChristoffer Dall <christoffer.dall@linaro.org>2013-08-07 18:17:28 -0700
commitd3840b26614d8ce3db53c98061d9fcb1b9ccb0dd (patch)
treeaf0294fc67a471ebf56404e456f2c344ef27345e /arch/arm/kvm
parent240e99cbd00aa541b572480e3ea7ecb0d480bc79 (diff)
downloadop-kernel-dev-d3840b26614d8ce3db53c98061d9fcb1b9ccb0dd.zip
op-kernel-dev-d3840b26614d8ce3db53c98061d9fcb1b9ccb0dd.tar.gz
ARM: KVM: Fix unaligned unmap_range leak
The unmap_range function did not properly cover the case when the start address was not aligned to PMD_SIZE or PUD_SIZE and an entire pte table or pmd table was cleared, causing us to leak memory when incrementing the addr. The fix is to always move onto the next page table entry boundary instead of adding the full size of the VA range covered by the corresponding table level entry. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r--arch/arm/kvm/mmu.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index ca6bea4..80a83ec 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -132,37 +132,37 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp,
pmd_t *pmd;
pte_t *pte;
unsigned long long addr = start, end = start + size;
- u64 range;
+ u64 next;
while (addr < end) {
pgd = pgdp + pgd_index(addr);
pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
- addr += PUD_SIZE;
+ addr = pud_addr_end(addr, end);
continue;
}
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
- addr += PMD_SIZE;
+ addr = pmd_addr_end(addr, end);
continue;
}
pte = pte_offset_kernel(pmd, addr);
clear_pte_entry(kvm, pte, addr);
- range = PAGE_SIZE;
+ next = addr + PAGE_SIZE;
/* If we emptied the pte, walk back up the ladder */
if (pte_empty(pte)) {
clear_pmd_entry(kvm, pmd, addr);
- range = PMD_SIZE;
+ next = pmd_addr_end(addr, end);
if (pmd_empty(pmd)) {
clear_pud_entry(kvm, pud, addr);
- range = PUD_SIZE;
+ next = pud_addr_end(addr, end);
}
}
- addr += range;
+ addr = next;
}
}
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