Re: [PATCH AUTOSEL 4.14 40/66] hv_netvsc: Validate number of allocated sub-channels

Sasha Levin
2020-12-23T14:16:03Z

On Wed, Dec 23, 2020 at 09:59:31AM +0100, Andrea Parri wrote:
>On Wed, Dec 23, 2020 at 02:47:56AM +0000, Michael Kelley wrote:
>> From: Sasha Levin <sashal@kernel.org> Sent: Tuesday, December 22, 2020 6:22 PM
>> >
>> > From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
>> >
>> > [ Upstream commit 206ad34d52a2f1205c84d08c12fc116aad0eb407 ]
>> >
>> > Lack of validation could lead to out-of-bound reads and information
>> > leaks (cf. usage of nvdev->chan_table[]). Check that the number of
>> > allocated sub-channels fits into the expected range.
>> >
>> > Suggested-by: Saruhan Karademir <skarade@microsoft.com>
>> > Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
>> > Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
>> > Acked-by: Jakub Kicinski <kuba@kernel.org>
>> > Cc: "David S. Miller" <davem@davemloft.net>
>> > Cc: Jakub Kicinski <kuba@kernel.org>
>> > Cc: netdev@vger.kernel.org
>> > Link:
>> > https://lore.kernel.org/linux-hyperv/20201118153310.112404-1-parri.andrea@gmail.com/
>> > Signed-off-by: Wei Liu <wei.liu@kernel.org>
>> > Signed-off-by: Sasha Levin <sashal@kernel.org>
>> > ---
>> > drivers/net/hyperv/rndis_filter.c | 5 +++++
>> > 1 file changed, 5 insertions(+)
>> >
>>
>> Sasha -- This patch is one of an ongoing group of patches where a Linux
>> guest running on Hyper-V will start assuming that hypervisor behavior might
>> be malicious, and guards against such behavior. Because this is a new
>> assumption, these patches are more properly treated as new functionality
>> rather than as bug fixes. So I would propose that we *not* bring such patches
>> back to stable branches.
>
>Thank you, Michael. Just to confirm, I agree with Michael's assessment
>above and I join his proposal to *not* backport such patches to stable.

I'll drop it then, thanks.

--
Thanks,
Sasha