4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Juerg Haefliger <juerg.haefliger@xxxxxxx>
[ 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 <juerg.haefliger@xxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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");
}