* [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose
@ 2020-01-02 23:49 Alexander Popov
2020-01-14 12:14 ` Alexander Popov
2020-01-22 11:58 ` Alexander Popov
0 siblings, 2 replies; 6+ messages in thread
From: Alexander Popov @ 2020-01-02 23:49 UTC (permalink / raw)
To: Kees Cook, Arnd Bergmann, Greg Kroah-Hartman, linux-kernel,
Alexander Popov
Cc: notify
Make the stack erasing test more verbose about the errors that it
can detect.
Signed-off-by: Alexander Popov <alex.popov@linux.com>
---
drivers/misc/lkdtm/stackleak.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/misc/lkdtm/stackleak.c b/drivers/misc/lkdtm/stackleak.c
index d5a084475abc..d1a5c0705be3 100644
--- a/drivers/misc/lkdtm/stackleak.c
+++ b/drivers/misc/lkdtm/stackleak.c
@@ -16,6 +16,7 @@ void lkdtm_STACKLEAK_ERASING(void)
unsigned long *sp, left, found, i;
const unsigned long check_depth =
STACKLEAK_SEARCH_DEPTH / sizeof(unsigned long);
+ bool test_failed = false;
/*
* For the details about the alignment of the poison values, see
@@ -34,7 +35,8 @@ void lkdtm_STACKLEAK_ERASING(void)
left--;
} else {
pr_err("FAIL: not enough stack space for the test\n");
- return;
+ test_failed = true;
+ goto end;
}
pr_info("checking unused part of the thread stack (%lu bytes)...\n",
@@ -52,22 +54,29 @@ void lkdtm_STACKLEAK_ERASING(void)
}
if (found <= check_depth) {
- pr_err("FAIL: thread stack is not erased (checked %lu bytes)\n",
+ pr_err("FAIL: the erased part is not found (checked %lu bytes)\n",
i * sizeof(unsigned long));
- return;
+ test_failed = true;
+ goto end;
}
- pr_info("first %lu bytes are unpoisoned\n",
+ pr_info("the erased part begins after %lu not poisoned bytes\n",
(i - found) * sizeof(unsigned long));
/* The rest of thread stack should be erased */
for (; i < left; i++) {
if (*(sp - i) != STACKLEAK_POISON) {
- pr_err("FAIL: thread stack is NOT properly erased\n");
- return;
+ pr_err("FAIL: bad value number %lu in the erased part: 0x%lx\n",
+ i, *(sp - i));
+ test_failed = true;
}
}
- pr_info("OK: the rest of the thread stack is properly erased\n");
- return;
+end:
+ if (test_failed) {
+ pr_err("FAIL: the thread stack is NOT properly erased\n");
+ dump_stack();
+ } else {
+ pr_info("OK: the rest of the thread stack is properly erased\n");
+ }
}
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose
2020-01-02 23:49 [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose Alexander Popov
@ 2020-01-14 12:14 ` Alexander Popov
2020-01-22 11:58 ` Alexander Popov
1 sibling, 0 replies; 6+ messages in thread
From: Alexander Popov @ 2020-01-14 12:14 UTC (permalink / raw)
To: Kees Cook, Arnd Bergmann, Greg Kroah-Hartman, linux-kernel; +Cc: notify
Hello!
Let me remind of this patch.
Best regards,
Alexander
On 03.01.2020 02:49, Alexander Popov wrote:
> Make the stack erasing test more verbose about the errors that it
> can detect.
>
> Signed-off-by: Alexander Popov <alex.popov@linux.com>
> ---
> drivers/misc/lkdtm/stackleak.c | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/misc/lkdtm/stackleak.c b/drivers/misc/lkdtm/stackleak.c
> index d5a084475abc..d1a5c0705be3 100644
> --- a/drivers/misc/lkdtm/stackleak.c
> +++ b/drivers/misc/lkdtm/stackleak.c
> @@ -16,6 +16,7 @@ void lkdtm_STACKLEAK_ERASING(void)
> unsigned long *sp, left, found, i;
> const unsigned long check_depth =
> STACKLEAK_SEARCH_DEPTH / sizeof(unsigned long);
> + bool test_failed = false;
>
> /*
> * For the details about the alignment of the poison values, see
> @@ -34,7 +35,8 @@ void lkdtm_STACKLEAK_ERASING(void)
> left--;
> } else {
> pr_err("FAIL: not enough stack space for the test\n");
> - return;
> + test_failed = true;
> + goto end;
> }
>
> pr_info("checking unused part of the thread stack (%lu bytes)...\n",
> @@ -52,22 +54,29 @@ void lkdtm_STACKLEAK_ERASING(void)
> }
>
> if (found <= check_depth) {
> - pr_err("FAIL: thread stack is not erased (checked %lu bytes)\n",
> + pr_err("FAIL: the erased part is not found (checked %lu bytes)\n",
> i * sizeof(unsigned long));
> - return;
> + test_failed = true;
> + goto end;
> }
>
> - pr_info("first %lu bytes are unpoisoned\n",
> + pr_info("the erased part begins after %lu not poisoned bytes\n",
> (i - found) * sizeof(unsigned long));
>
> /* The rest of thread stack should be erased */
> for (; i < left; i++) {
> if (*(sp - i) != STACKLEAK_POISON) {
> - pr_err("FAIL: thread stack is NOT properly erased\n");
> - return;
> + pr_err("FAIL: bad value number %lu in the erased part: 0x%lx\n",
> + i, *(sp - i));
> + test_failed = true;
> }
> }
>
> - pr_info("OK: the rest of the thread stack is properly erased\n");
> - return;
> +end:
> + if (test_failed) {
> + pr_err("FAIL: the thread stack is NOT properly erased\n");
> + dump_stack();
> + } else {
> + pr_info("OK: the rest of the thread stack is properly erased\n");
> + }
> }
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose
2020-01-02 23:49 [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose Alexander Popov
2020-01-14 12:14 ` Alexander Popov
@ 2020-01-22 11:58 ` Alexander Popov
2020-01-27 23:15 ` Kees Cook
1 sibling, 1 reply; 6+ messages in thread
From: Alexander Popov @ 2020-01-22 11:58 UTC (permalink / raw)
To: Kees Cook, Arnd Bergmann, Greg Kroah-Hartman, linux-kernel; +Cc: notify
On 03.01.2020 02:49, Alexander Popov wrote:
> Make the stack erasing test more verbose about the errors that it
> can detect.
>
> Signed-off-by: Alexander Popov <alex.popov@linux.com>
> ---
> drivers/misc/lkdtm/stackleak.c | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
Hello!
Pinging about this version of the patch.
Kees, it uses dump_stack() instead of BUG(), as we negotiated.
Thanks!
Alexander
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose
2020-01-22 11:58 ` Alexander Popov
@ 2020-01-27 23:15 ` Kees Cook
2020-01-28 7:50 ` Greg Kroah-Hartman
0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2020-01-27 23:15 UTC (permalink / raw)
To: Alexander Popov; +Cc: Arnd Bergmann, Greg Kroah-Hartman, linux-kernel, notify
On Wed, Jan 22, 2020 at 02:58:44PM +0300, Alexander Popov wrote:
> On 03.01.2020 02:49, Alexander Popov wrote:
> > Make the stack erasing test more verbose about the errors that it
> > can detect.
> >
> > Signed-off-by: Alexander Popov <alex.popov@linux.com>
> > ---
> > drivers/misc/lkdtm/stackleak.c | 25 +++++++++++++++++--------
> > 1 file changed, 17 insertions(+), 8 deletions(-)
>
> Hello!
>
> Pinging about this version of the patch.
>
> Kees, it uses dump_stack() instead of BUG(), as we negotiated.
Yup, this is in my queue -- I've just gotten back from travelling and
will get to it shortly. :)
Greg, feel free to take this directly if you want, too.
-Kees
--
Kees Cook
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose
2020-01-27 23:15 ` Kees Cook
@ 2020-01-28 7:50 ` Greg Kroah-Hartman
2020-01-28 23:03 ` Kees Cook
0 siblings, 1 reply; 6+ messages in thread
From: Greg Kroah-Hartman @ 2020-01-28 7:50 UTC (permalink / raw)
To: Kees Cook; +Cc: Alexander Popov, Arnd Bergmann, linux-kernel, notify
On Mon, Jan 27, 2020 at 03:15:08PM -0800, Kees Cook wrote:
> On Wed, Jan 22, 2020 at 02:58:44PM +0300, Alexander Popov wrote:
> > On 03.01.2020 02:49, Alexander Popov wrote:
> > > Make the stack erasing test more verbose about the errors that it
> > > can detect.
> > >
> > > Signed-off-by: Alexander Popov <alex.popov@linux.com>
> > > ---
> > > drivers/misc/lkdtm/stackleak.c | 25 +++++++++++++++++--------
> > > 1 file changed, 17 insertions(+), 8 deletions(-)
> >
> > Hello!
> >
> > Pinging about this version of the patch.
> >
> > Kees, it uses dump_stack() instead of BUG(), as we negotiated.
>
> Yup, this is in my queue -- I've just gotten back from travelling and
> will get to it shortly. :)
>
> Greg, feel free to take this directly if you want, too.
If I were to take it, it would have to wait until after 5.6-rc1, sorry.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose
2020-01-28 7:50 ` Greg Kroah-Hartman
@ 2020-01-28 23:03 ` Kees Cook
0 siblings, 0 replies; 6+ messages in thread
From: Kees Cook @ 2020-01-28 23:03 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: Alexander Popov, Arnd Bergmann, linux-kernel, notify
On Tue, Jan 28, 2020 at 08:50:50AM +0100, Greg Kroah-Hartman wrote:
> On Mon, Jan 27, 2020 at 03:15:08PM -0800, Kees Cook wrote:
> > On Wed, Jan 22, 2020 at 02:58:44PM +0300, Alexander Popov wrote:
> > > On 03.01.2020 02:49, Alexander Popov wrote:
> > > > Make the stack erasing test more verbose about the errors that it
> > > > can detect.
> > > >
> > > > Signed-off-by: Alexander Popov <alex.popov@linux.com>
> > > > ---
> > > > drivers/misc/lkdtm/stackleak.c | 25 +++++++++++++++++--------
> > > > 1 file changed, 17 insertions(+), 8 deletions(-)
> > >
> > > Hello!
> > >
> > > Pinging about this version of the patch.
> > >
> > > Kees, it uses dump_stack() instead of BUG(), as we negotiated.
> >
> > Yup, this is in my queue -- I've just gotten back from travelling and
> > will get to it shortly. :)
> >
> > Greg, feel free to take this directly if you want, too.
>
> If I were to take it, it would have to wait until after 5.6-rc1, sorry.
Well, it has to go via drivers/misc anyway, so I think timing is no
different. I would consider this a feature patch, not a bug fix, too.
--
Kees Cook
^ permalink raw reply [flat|nested] 6+ messages in thread
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2020-01-02 23:49 [PATCH v2 1/1] lkdtm/stackleak: Make the test more verbose Alexander Popov
2020-01-14 12:14 ` Alexander Popov
2020-01-22 11:58 ` Alexander Popov
2020-01-27 23:15 ` Kees Cook
2020-01-28 7:50 ` Greg Kroah-Hartman
2020-01-28 23:03 ` Kees Cook
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