On Wed, Feb 24, 2021 at 07:50:08AM -0500, Sasha Levin wrote:
> From: "Andrea Parri (Microsoft)" <parri.and...@gmail.com>
>
> [ Upstream commit e99c4afbee07e9323e9191a20b24d74dbf815bdf ]
>
> __vmbus_open() and vmbus_teardown_gpadl() do not inizialite the memory
> for the vmbus_channel_open_channel and the vmbus_channel_gpadl_teardown
> objects they allocate respectively. These objects contain padding bytes
> and fields that are left uninitialized and that are later sent to the
> host, potentially leaking guest data. Zero initialize such fields to
> avoid leaking sensitive information to the host.
>
> Reported-by: Juan Vazquez <juv...@microsoft.com>
> Signed-off-by: Andrea Parri (Microsoft) <parri.and...@gmail.com>
> Reviewed-by: Michael Kelley <mikel...@microsoft.com>
> Link: https://lore.kernel.org/r/20201209070827.29335-2-parri.and...@gmail.com
> Signed-off-by: Wei Liu <wei....@kernel.org>
> Signed-off-by: Sasha Levin <sas...@kernel.org>
Sasha - This patch is one of a 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.
Thanks,
Andrea
> ---
> drivers/hv/channel.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
> index 6fb0c76bfbf81..0bd202de79600 100644
> --- a/drivers/hv/channel.c
> +++ b/drivers/hv/channel.c
> @@ -618,7 +618,7 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
> goto error_clean_ring;
>
> /* Create and init the channel open message */
> - open_info = kmalloc(sizeof(*open_info) +
> + open_info = kzalloc(sizeof(*open_info) +
> sizeof(struct vmbus_channel_open_channel),
> GFP_KERNEL);
> if (!open_info) {
> @@ -745,7 +745,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel,
> u32 gpadl_handle)
> unsigned long flags;
> int ret;
>
> - info = kmalloc(sizeof(*info) +
> + info = kzalloc(sizeof(*info) +
> sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
> if (!info)
> return -ENOMEM;
> --
> 2.27.0
>
