rpms
/
kernel
2
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

CVE-2015-7513 kvm: divide by zero DoS (rhbz 1284847 1296142)

This commit is contained in:
Josh Boyer 2016-01-07 08:49:29 -05:00
parent c7ce3af191
commit c996788da5
2 changed files with 63 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
KVM-x86-Reload-pit-counters-for-all-channels-when-re.patch Normal file
View File

@ -0,0 +1,59 @@
From f3b9db45027a40369fe13c4661c4249d1df8c8d0 Mon Sep 17 00:00:00 2001
From: Andrew Honig <ahonig@google.com>
Date: Wed, 18 Nov 2015 14:50:23 -0800
Subject: [PATCH] KVM: x86: Reload pit counters for all channels when restoring
state
Currently if userspace restores the pit counters with a count of 0
on channels 1 or 2 and the guest attempts to read the count on those
channels, then KVM will perform a mod of 0 and crash. This will ensure
that 0 values are converted to 65536 as per the spec.
This is CVE-2015-7513.
Signed-off-by: Andy Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Backported to 4.3.y by Josh Boyer <jwboyer@fedoraproject.org>]
---
arch/x86/kvm/x86.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 43609af03283..e124f9c8391e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3437,10 +3437,11 @@ static int kvm_vm_ioctl_get_pit(struct kvm *kvm, struct kvm_pit_state *ps)
static int kvm_vm_ioctl_set_pit(struct kvm *kvm, struct kvm_pit_state *ps)
{
int r = 0;
-
+ int i;
mutex_lock(&kvm->arch.vpit->pit_state.lock);
memcpy(&kvm->arch.vpit->pit_state, ps, sizeof(struct kvm_pit_state));
- kvm_pit_load_count(kvm, 0, ps->channels[0].count, 0);
+ for (i = 0; i < 3; i++)
+ kvm_pit_load_count(kvm, i, ps->channels[i].count, 0);
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
return r;
}
@@ -3461,6 +3462,7 @@ static int kvm_vm_ioctl_get_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
static int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
{
int r = 0, start = 0;
+ int i;
u32 prev_legacy, cur_legacy;
mutex_lock(&kvm->arch.vpit->pit_state.lock);
prev_legacy = kvm->arch.vpit->pit_state.flags & KVM_PIT_FLAGS_HPET_LEGACY;
@@ -3470,7 +3472,8 @@ static int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
memcpy(&kvm->arch.vpit->pit_state.channels, &ps->channels,
sizeof(kvm->arch.vpit->pit_state.channels));
kvm->arch.vpit->pit_state.flags = ps->flags;
- kvm_pit_load_count(kvm, 0, kvm->arch.vpit->pit_state.channels[0].count, start);
+ for (i = 0; i < 3; i++)
+ kvm_pit_load_count(kvm, i, kvm->arch.vpit->pit_state.channels[i].count, start);
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
return r;
}
--
2.5.0

4
kernel.spec
View File

@ -650,6 +650,9 @@ Patch603: ptrace-being-capable-wrt-a-process-requires-mapped-u.patch
Patch604: drm-i915-shut-up-gen8-SDE-irq-dmesg-noise-again.patch
#CVE-2015-7513 rhbz 1284847 1296142
Patch605: KVM-x86-Reload-pit-counters-for-all-channels-when-re.patch
# END OF PATCH DEFINITIONS
%endif
@ -2094,6 +2097,7 @@ fi
#
%changelog
* Thu Jan 07 2016 Josh Boyer <jwboyer@fedorparoject.org>
- CVE-2015-7513 kvm: divide by zero DoS (rhbz 1284847 1296142)
- Quiet i915 gen8 irq messages
* Tue Jan 05 2016 Josh Boyer <jwboyer@fedoraproject.org>