| Message ID | 1365671384-12832-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 26fd54d..fdb1faf 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -73,9 +73,12 @@ 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;
This is a note to let you know that I have just added a patch titled KVM: Fix bounds checking in ioapic indirect register reads to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 7d2891cde449076d4425e94c0c6a9ad6e9acd9b6 Mon Sep 17 00:00:00 2001 From: Andy Honig <ahonig@google.com> Date: Wed, 20 Feb 2013 14:49:16 -0800 Subject: [PATCH] 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@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- virt/kvm/ioapic.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) -- 1.8.1.2