From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Juerg Haefliger , Kees Cook , Sasha Levin Subject: [PATCH 4.9 057/104] lkdtm: Fix Oops when unloading the module Date: Fri, 6 Oct 2017 10:51:35 +0200 Message-Id: <20171006083849.187864208@linuxfoundation.org> In-Reply-To: <20171006083840.743659740@linuxfoundation.org> References: <20171006083840.743659740@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Juerg Haefliger [ Upstream commit 9ba60573638e2006170ebcc5489fb1e068afbc8f ] No jprobe is registered when the module is loaded without specifying a crashpoint that uses a jprobe. At the moment, we unconditionally try to unregister the jprobe on module unload which results in an Oops. Add a check to fix this. Signed-off-by: Juerg Haefliger Acked-by: Kees Cook Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/misc/lkdtm_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/misc/lkdtm_core.c +++ b/drivers/misc/lkdtm_core.c @@ -533,7 +533,9 @@ static void __exit lkdtm_module_exit(voi /* Handle test-specific clean-up. */ lkdtm_usercopy_exit(); - unregister_jprobe(lkdtm_jprobe); + if (lkdtm_jprobe != NULL) + unregister_jprobe(lkdtm_jprobe); + pr_info("Crash point unregistered\n"); }