Guest driver might execute HW commands when shared buffers are not yet
allocated.
This could happen on purpose (malicious guest) or because of some other
guest/host address mapping error.
We need to protect againts such case.
Fixes: CVE-2022-1050
Reported-by: Raven <wxhusst@gmail.com>
Signed-off-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Message-Id: <20220403095234.2210-1-yuval.shaia.ml@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
(cherry picked from commit 31c4b6fb0293e359f9ef8a61892667e76eea4c99)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>