* [PATCH] lkdtm: Fix Oops when unloading the module
@ 2017-01-19 10:40 Juerg Haefliger
2017-01-19 22:03 ` Kees Cook
0 siblings, 1 reply; 3+ messages in thread
From: Juerg Haefliger @ 2017-01-19 10:40 UTC (permalink / raw)
To: keescook, linux-kernel; +Cc: Juerg Haefliger
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>
---
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 7eeb71a75549..4d44084071d8 100644
--- a/drivers/misc/lkdtm_core.c
+++ b/drivers/misc/lkdtm_core.c
@@ -535,7 +535,9 @@ 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");
}
--
2.11.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] lkdtm: Fix Oops when unloading the module
2017-01-19 10:40 [PATCH] lkdtm: Fix Oops when unloading the module Juerg Haefliger
@ 2017-01-19 22:03 ` Kees Cook
2017-01-20 10:01 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Kees Cook @ 2017-01-19 22:03 UTC (permalink / raw)
To: Juerg Haefliger, Greg KH; +Cc: LKML
On Thu, Jan 19, 2017 at 2:40 AM, Juerg Haefliger
<juerg.haefliger@hpe.com> wrote:
> 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>
Ah-ha, nice catch, thanks!
Acked-by: Kees Cook <keescook@chromium.org>
Greg, can you please add this to your tree when you get a chance?
-Kees
> ---
> 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 7eeb71a75549..4d44084071d8 100644
> --- a/drivers/misc/lkdtm_core.c
> +++ b/drivers/misc/lkdtm_core.c
> @@ -535,7 +535,9 @@ 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");
> }
>
> --
> 2.11.0
>
--
Kees Cook
Nexus Security
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] lkdtm: Fix Oops when unloading the module
2017-01-19 22:03 ` Kees Cook
@ 2017-01-20 10:01 ` Greg KH
0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2017-01-20 10:01 UTC (permalink / raw)
To: Kees Cook; +Cc: Juerg Haefliger, LKML
On Thu, Jan 19, 2017 at 02:03:11PM -0800, Kees Cook wrote:
> On Thu, Jan 19, 2017 at 2:40 AM, Juerg Haefliger
> <juerg.haefliger@hpe.com> wrote:
> > 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>
>
> Ah-ha, nice catch, thanks!
>
> Acked-by: Kees Cook <keescook@chromium.org>
>
> Greg, can you please add this to your tree when you get a chance?
Will do, thanks.
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-01-19 22:03 ` Kees Cook
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