Patch "lkdtm: Fix Oops when unloading the module" has been added to the 4.9-stable tree

Patch "lkdtm: Fix Oops when unloading the module" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    lkdtm: Fix Oops when unloading the module

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     lkdtm-fix-oops-when-unloading-the-module.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Oct  5 10:28:31 CEST 2017
From: Juerg Haefliger <juerg.haefliger@hpe.com>
Date: Thu, 19 Jan 2017 11:40:13 +0100
Subject: lkdtm: Fix Oops when unloading the module

From: Juerg Haefliger <juerg.haefliger@hpe.com>


[ 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@hpe.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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");
 }
 


Patches currently in stable-queue which might be from juerg.haefliger@hpe.com are

queue-4.9/lkdtm-fix-oops-when-unloading-the-module.patch