From c593091cfc1bee31b56b555c83dc5f0ed715d7ed Mon Sep 17 00:00:00 2001 From: Juerg Haefliger Date: Thu, 19 Jan 2017 11:40:13 +0100 Subject: [PATCH] lkdtm: Fix Oops when unloading the module [ 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(-) diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c index f9154b8d67f6..b2989f2d3126 100644 --- a/drivers/misc/lkdtm_core.c +++ b/drivers/misc/lkdtm_core.c @@ -533,7 +533,9 @@ static void __exit lkdtm_module_exit(void) /* 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"); } -- 2.17.1