Re: CVE request: kvm: integer overflow in kvm_dev_ioctl_get_supported_cpuid()

[Josh Bressers <bressers () redhat com>]

Please use CVE-2009-3638 for this.

Thanks.

-- 
    JB


----- "Eugene Teo" <eugeneteo () kernel sg> wrote:

> Quote from the upstream commit:
> "The number of entries is multiplied by the entry size, which can 
> overflow on 32-bit hosts.  Bound the entry count instead."
>
>    if (cpuid->nent < 1)
>     goto out;
> + if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
> +  cpuid->nent = KVM_MAX_CPUID_ENTRIES;
>    r = -ENOMEM;
>    cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry2) *
> cpuid->nent);
>    if (!cpuid_entries)
>
> This one can be triggered if /dev/kvm is user accessible (which is
> recommended...). This was introduced in v2.6.25-rc1, and fixed in 
> v2.6.32-rc4. Only on 32-bit host.
>
> References:
> http://git.kernel.org/linus/0771671749b59a507b6da4efb931c44d9691e248
> http://git.kernel.org/linus/6a54435560efdab1a08f429a954df4d6c740bddf
> https://bugzilla.redhat.com/show_bug.cgi?id=530515
>
> Thanks, Eugene