[ Upstream commit f8aa1b98ce40184521ed95ec26cc115a255183b2 ] There is a race condition when a kthread finishes after the deadline and before the call to kthread_stop(), which may lead to use after free. Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Fixes: adf505457032 ("kunit: fix UAF when run kfence test case test_gfpzero") Reviewed-by: David Gow <davidgow@google.com> Reviewed-by: Rae Moar <rmoar@google.com> Signed-off-by: Mickaël Salaün <mic@digikod.net> Link: https://lore.kernel.org/r/20240408074625.65017-3-mic@digikod.net Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>