[libvirt] [PATCH] util: Fix crash of libvirtd when running numatune with invalid nodeset
Peter Krempa
pkrempa at redhat.com
Fri Aug 16 09:16:16 UTC 2013
On 08/16/13 09:47, Alex Jia wrote:
> This issue is introduced by commit 0fc8909, the virBitmapIsSet() needs caller
> to ensure 'b < bitmap->max_bit', but it's lost in the virBitmapParse() caller,
> this will cause crash of libvirtd, with the patch, libvirtd no crash and can
> get a expected error "Failed to parse nodeset".
>
> How to reproduce?
>
> # virsh numatune foo --nodeset 1000000000
> Actual result:
> error: Unable to change numa parameters
> error: End of file while reading data: Input/output error
> error: One or more references were leaked after disconnect from the hypervisor
> error: Failed to reconnect to the hypervisor
>
> GDB backtrace:
>
....
>
> RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=997367
>
> Signed-off-by: Alex Jia <ajia at redhat.com>
> ---
> The caller virBitmapGetBit() can make sure 'b < bitmap->max_bit', so don't
> need to worry about higher caller for the virBitmapGetBit(), but the
> virBitmapParse() is called by many XML parser function, not sure which one
> can crash libvirtd with read-only client then probably require a CVE, I haven't
> a good way to check them now and only manually check them one by one.
>
> src/util/virbitmap.c | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/src/util/virbitmap.c b/src/util/virbitmap.c
> index 7e1cd02..edbfb30 100644
> --- a/src/util/virbitmap.c
> +++ b/src/util/virbitmap.c
> @@ -337,6 +337,9 @@ virBitmapParse(const char *str,
> if (start < 0)
> goto parse_error;
>
> + if ((*bitmap)->max_bit <= start)
> + goto parse_error;
> +
This will check only the start value of a range. When you use a range
that starts with a valid number "1-1000000000000" for example, then the
loop that is setting bits from the range will triger the crash too.
IMO the correct fix here is to get rid of the weird construction:
if (!virBitmapIsSet(*bitmap, i)) {
ignore_value(virBitmapSetBit(*bitmap, i));
ret++;
}
with
if (virBitmapSetBit(*bitmap, i) < 0)
goto error;
and at the end count the enabled bits as
ret = virBitmapCountBits(*bitmap);
instead of the code that is present.
I'll post an updated version of this patch containing the suggested changes.
Peter
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 901 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20130816/a9ef8993/attachment-0001.sig>
More information about the libvir-list
mailing list