On Wed, Feb 24, 2021 at 02:16:00PM +0100, Andrea Parri wrote:

On Wed, Feb 24, 2021 at 07:50:08AM -0500, Sasha Levin wrote:

quoted

From: "Andrea Parri (Microsoft)" <parri.andrea@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 <redacted>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <redacted>
Link: https://lore.kernel.org/r/20201209070827.29335-2-parri.andrea@gmail.com (local)
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Sasha Levin <sashal@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.

For future/similar cases: I'm wondering, is there some way to annotate a patch
with "please do not bring it back"?

Thanks,
  Andrea