[kernel] r19947 - in dists/sid/linux/debian: . patches patches/bugfix/all patches/bugfix/x86
Ben Hutchings
benh at alioth.debian.org
Mon Mar 25 14:30:20 UTC 2013
Author: benh
Date: Mon Mar 25 14:30:20 2013
New Revision: 19947
Log:
Apply KVM security fixes
Added:
dists/sid/linux/debian/patches/bugfix/all/KVM-Fix-bounds-checking-in-ioapic-indirect-register-.patch
dists/sid/linux/debian/patches/bugfix/x86/KVM-x86-Convert-MSR_KVM_SYSTEM_TIME-to-use-gfn_to_hv.patch
dists/sid/linux/debian/patches/bugfix/x86/KVM-x86-fix-for-buffer-overflow-in-handling-of-MSR_K.patch
Modified:
dists/sid/linux/debian/changelog
dists/sid/linux/debian/patches/series
Modified: dists/sid/linux/debian/changelog
==============================================================================
--- dists/sid/linux/debian/changelog Mon Mar 25 13:37:43 2013 (r19946)
+++ dists/sid/linux/debian/changelog Mon Mar 25 14:30:20 2013 (r19947)
@@ -7,6 +7,11 @@
* [x86] drm/i915: bounds check execbuffer relocation count (CVE-2013-0913)
* [x86] drm: Enable DRM_GMA500 as module, replacing DRM_PSB (Closes: #703506)
- Enable DRM_GMA600, DRM_GMA3600, DRM_MEDFIELD
+ * [x86] KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME
+ (CVE-2013-1796)
+ * [x86] KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache
+ functions (CVE-2013-1797)
+ * KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)
-- Ben Hutchings <ben at decadent.org.uk> Sat, 23 Mar 2013 17:45:03 +0000
Added: dists/sid/linux/debian/patches/bugfix/all/KVM-Fix-bounds-checking-in-ioapic-indirect-register-.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/all/KVM-Fix-bounds-checking-in-ioapic-indirect-register-.patch Mon Mar 25 14:30:20 2013 (r19947)
@@ -0,0 +1,42 @@
+From: Andy Honig <ahonig at google.com>
+Date: Wed, 20 Feb 2013 14:49:16 -0800
+Subject: KVM: Fix bounds checking in ioapic indirect register reads
+ (CVE-2013-1798)
+
+commit a2c118bfab8bc6b8bb213abfc35201e441693d55 upstream.
+
+If the guest specifies a IOAPIC_REG_SELECT with an invalid value and follows
+that with a read of the IOAPIC_REG_WINDOW KVM does not properly validate
+that request. ioapic_read_indirect contains an
+ASSERT(redir_index < IOAPIC_NUM_PINS), but the ASSERT has no effect in
+non-debug builds. In recent kernels this allows a guest to cause a kernel
+oops by reading invalid memory. In older kernels (pre-3.3) this allows a
+guest to read from large ranges of host memory.
+
+Tested: tested against apic unit tests.
+
+Signed-off-by: Andrew Honig <ahonig at google.com>
+Signed-off-by: Marcelo Tosatti <mtosatti at redhat.com>
+---
+ virt/kvm/ioapic.c | 7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
+index ce82b94..5ba005c 100644
+--- a/virt/kvm/ioapic.c
++++ b/virt/kvm/ioapic.c
+@@ -74,9 +74,12 @@ static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
+ u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
+ u64 redir_content;
+
+- ASSERT(redir_index < IOAPIC_NUM_PINS);
++ if (redir_index < IOAPIC_NUM_PINS)
++ redir_content =
++ ioapic->redirtbl[redir_index].bits;
++ else
++ redir_content = ~0ULL;
+
+- redir_content = ioapic->redirtbl[redir_index].bits;
+ result = (ioapic->ioregsel & 0x1) ?
+ (redir_content >> 32) & 0xffffffff :
+ redir_content & 0xffffffff;
Added: dists/sid/linux/debian/patches/bugfix/x86/KVM-x86-Convert-MSR_KVM_SYSTEM_TIME-to-use-gfn_to_hv.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/x86/KVM-x86-Convert-MSR_KVM_SYSTEM_TIME-to-use-gfn_to_hv.patch Mon Mar 25 14:30:20 2013 (r19947)
@@ -0,0 +1,134 @@
+From: Andy Honig <ahonig at google.com>
+Date: Wed, 20 Feb 2013 14:48:10 -0800
+Subject: KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache
+ functions (CVE-2013-1797)
+
+commit 0b79459b482e85cb7426aa7da683a9f2c97aeae1 upstream.
+
+There is a potential use after free issue with the handling of
+MSR_KVM_SYSTEM_TIME. If the guest specifies a GPA in a movable or removable
+memory such as frame buffers then KVM might continue to write to that
+address even after it's removed via KVM_SET_USER_MEMORY_REGION. KVM pins
+the page in memory so it's unlikely to cause an issue, but if the user
+space component re-purposes the memory previously used for the guest, then
+the guest will be able to corrupt that memory.
+
+Tested: Tested against kvmclock unit test
+
+Signed-off-by: Andrew Honig <ahonig at google.com>
+Signed-off-by: Marcelo Tosatti <mtosatti at redhat.com>
+[bwh: Backported to 3.2:
+ - Adjust context
+ - We do not implement the PVCLOCK_GUEST_STOPPED flag]
+---
+ arch/x86/include/asm/kvm_host.h | 4 ++--
+ arch/x86/kvm/x86.c | 47 +++++++++++++++++----------------------
+ 2 files changed, 22 insertions(+), 29 deletions(-)
+
+--- a/arch/x86/include/asm/kvm_host.h
++++ b/arch/x86/include/asm/kvm_host.h
+@@ -393,8 +393,8 @@ struct kvm_vcpu_arch {
+ gpa_t time;
+ struct pvclock_vcpu_time_info hv_clock;
+ unsigned int hw_tsc_khz;
+- unsigned int time_offset;
+- struct page *time_page;
++ struct gfn_to_hva_cache pv_time;
++ bool pv_time_enabled;
+
+ struct {
+ u64 msr_val;
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -1105,7 +1105,6 @@ static int kvm_guest_time_update(struct
+ {
+ unsigned long flags;
+ struct kvm_vcpu_arch *vcpu = &v->arch;
+- void *shared_kaddr;
+ unsigned long this_tsc_khz;
+ s64 kernel_ns, max_kernel_ns;
+ u64 tsc_timestamp;
+@@ -1141,7 +1140,7 @@ static int kvm_guest_time_update(struct
+
+ local_irq_restore(flags);
+
+- if (!vcpu->time_page)
++ if (!vcpu->pv_time_enabled)
+ return 0;
+
+ /*
+@@ -1199,14 +1198,9 @@ static int kvm_guest_time_update(struct
+ */
+ vcpu->hv_clock.version += 2;
+
+- shared_kaddr = kmap_atomic(vcpu->time_page, KM_USER0);
+-
+- memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock,
+- sizeof(vcpu->hv_clock));
+-
+- kunmap_atomic(shared_kaddr, KM_USER0);
+-
+- mark_page_dirty(v->kvm, vcpu->time >> PAGE_SHIFT);
++ kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
++ &vcpu->hv_clock,
++ sizeof(vcpu->hv_clock));
+ return 0;
+ }
+
+@@ -1496,10 +1490,7 @@ static int kvm_pv_enable_async_pf(struct
+
+ static void kvmclock_reset(struct kvm_vcpu *vcpu)
+ {
+- if (vcpu->arch.time_page) {
+- kvm_release_page_dirty(vcpu->arch.time_page);
+- vcpu->arch.time_page = NULL;
+- }
++ vcpu->arch.pv_time_enabled = false;
+ }
+
+ static void accumulate_steal_time(struct kvm_vcpu *vcpu)
+@@ -1591,6 +1582,7 @@ int kvm_set_msr_common(struct kvm_vcpu *
+ break;
+ case MSR_KVM_SYSTEM_TIME_NEW:
+ case MSR_KVM_SYSTEM_TIME: {
++ u64 gpa_offset;
+ kvmclock_reset(vcpu);
+
+ vcpu->arch.time = data;
+@@ -1600,21 +1592,17 @@ int kvm_set_msr_common(struct kvm_vcpu *
+ if (!(data & 1))
+ break;
+
+- /* ...but clean it before doing the actual write */
+- vcpu->arch.time_offset = data & ~(PAGE_MASK | 1);
++ gpa_offset = data & ~(PAGE_MASK | 1);
+
+ /* Check that the address is 32-byte aligned. */
+- if (vcpu->arch.time_offset &
+- (sizeof(struct pvclock_vcpu_time_info) - 1))
++ if (gpa_offset & (sizeof(struct pvclock_vcpu_time_info) - 1))
+ break;
+
+- vcpu->arch.time_page =
+- gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);
+-
+- if (is_error_page(vcpu->arch.time_page)) {
+- kvm_release_page_clean(vcpu->arch.time_page);
+- vcpu->arch.time_page = NULL;
+- }
++ if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
++ &vcpu->arch.pv_time, data & ~1ULL))
++ vcpu->arch.pv_time_enabled = false;
++ else
++ vcpu->arch.pv_time_enabled = true;
+ break;
+ }
+ case MSR_KVM_ASYNC_PF_EN:
+@@ -6559,6 +6547,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *
+ if (!zalloc_cpumask_var(&vcpu->arch.wbinvd_dirty_mask, GFP_KERNEL))
+ goto fail_free_mce_banks;
+
++ vcpu->arch.pv_time_enabled = false;
+ kvm_async_pf_hash_reset(vcpu);
+
+ return 0;
Added: dists/sid/linux/debian/patches/bugfix/x86/KVM-x86-fix-for-buffer-overflow-in-handling-of-MSR_K.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux/debian/patches/bugfix/x86/KVM-x86-fix-for-buffer-overflow-in-handling-of-MSR_K.patch Mon Mar 25 14:30:20 2013 (r19947)
@@ -0,0 +1,39 @@
+From: Andy Honig <ahonig at google.com>
+Date: Mon, 11 Mar 2013 09:34:52 -0700
+Subject: KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME
+ (CVE-2013-1796)
+
+commit c300aa64ddf57d9c5d9c898a64b36877345dd4a9 upstream.
+
+If the guest sets the GPA of the time_page so that the request to update the
+time straddles a page then KVM will write onto an incorrect page. The
+write is done byusing kmap atomic to get a pointer to the page for the time
+structure and then performing a memcpy to that page starting at an offset
+that the guest controls. Well behaved guests always provide a 32-byte aligned
+address, however a malicious guest could use this to corrupt host kernel
+memory.
+
+Tested: Tested against kvmclock unit test.
+
+Signed-off-by: Andrew Honig <ahonig at google.com>
+Signed-off-by: Marcelo Tosatti <mtosatti at redhat.com>
+---
+ arch/x86/kvm/x86.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
+index f7c850b..2ade60c 100644
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -1959,6 +1959,11 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
+ /* ...but clean it before doing the actual write */
+ vcpu->arch.time_offset = data & ~(PAGE_MASK | 1);
+
++ /* Check that the address is 32-byte aligned. */
++ if (vcpu->arch.time_offset &
++ (sizeof(struct pvclock_vcpu_time_info) - 1))
++ break;
++
+ vcpu->arch.time_page =
+ gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);
+
Modified: dists/sid/linux/debian/patches/series
==============================================================================
--- dists/sid/linux/debian/patches/series Mon Mar 25 13:37:43 2013 (r19946)
+++ dists/sid/linux/debian/patches/series Mon Mar 25 14:30:20 2013 (r19947)
@@ -636,3 +636,6 @@
bugfix/all/efivars-pstore-do-not-check-size-when-erasing-variable.patch
debian/efivars-remove-check-for-50-full-on-write.patch
bugfix/x86/drm-i915-bounds-check-execbuffer-relocation-count.patch
+bugfix/x86/KVM-x86-fix-for-buffer-overflow-in-handling-of-MSR_K.patch
+bugfix/x86/KVM-x86-Convert-MSR_KVM_SYSTEM_TIME-to-use-gfn_to_hv.patch
+bugfix/all/KVM-Fix-bounds-checking-in-ioapic-indirect-register-.patch
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