* [PATCH] Check that strnlen won't go beyond the maximum length
@ 2021-03-27 16:24 H.J. Lu
2021-03-27 17:51 ` Florian Weimer
0 siblings, 1 reply; 5+ messages in thread
From: H.J. Lu @ 2021-03-27 16:24 UTC (permalink / raw)
To: libc-alpha
Run strnlen tests on strings without the null byte around the page
boundary.
---
string/test-strnlen.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/string/test-strnlen.c b/string/test-strnlen.c
index 61eb521dc1..a49d93afa2 100644
--- a/string/test-strnlen.c
+++ b/string/test-strnlen.c
@@ -196,6 +196,31 @@ do_page_tests (void)
}
}
+/* Tests meant to unveil fail on implementation that does not access bytes
+ without the null character around the page boundary accordingly. */
+static void
+do_page_2_tests (void)
+{
+ size_t i, exp_len, offset;
+ size_t last_offset = page_size / sizeof (CHAR);
+
+ CHAR *s = (CHAR *) buf2;
+ memset (s, 65, page_size);
+
+ /* Place short strings ending at page boundary. */
+ offset = last_offset;
+ for (i = 0; i < 128; i++)
+ {
+ /* Decrease offset to stress several sizes and alignments. */
+ offset--;
+ exp_len = last_offset - offset;
+ FOR_EACH_IMPL (impl, 0)
+ {
+ do_one_test (impl, (CHAR *) (s + offset), exp_len, exp_len);
+ }
+ }
+}
+
int
test_main (void)
{
@@ -242,6 +267,7 @@ test_main (void)
do_random_tests ();
do_page_tests ();
+ do_page_2_tests ();
return ret;
}
--
2.30.2
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Check that strnlen won't go beyond the maximum length
2021-03-27 16:24 [PATCH] Check that strnlen won't go beyond the maximum length H.J. Lu
@ 2021-03-27 17:51 ` Florian Weimer
2021-03-27 18:09 ` [PATCH v2] test-strnlen.c: " H.J. Lu
0 siblings, 1 reply; 5+ messages in thread
From: Florian Weimer @ 2021-03-27 17:51 UTC (permalink / raw)
To: H.J. Lu via Libc-alpha
* H. J. Lu via Libc-alpha:
> Run strnlen tests on strings without the null byte around the page
> boundary.
> ---
> string/test-strnlen.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/string/test-strnlen.c b/string/test-strnlen.c
> index 61eb521dc1..a49d93afa2 100644
> --- a/string/test-strnlen.c
> +++ b/string/test-strnlen.c
> @@ -196,6 +196,31 @@ do_page_tests (void)
> }
> }
>
> +/* Tests meant to unveil fail on implementation that does not access bytes
> + without the null character around the page boundary accordingly. */
I don't understand the comment. Based on it, I would have expected a
null byte at the page boundary, which is incorrectly ignored by the
implementation.
> +static void
> +do_page_2_tests (void)
> +{
> + size_t i, exp_len, offset;
> + size_t last_offset = page_size / sizeof (CHAR);
> +
> + CHAR *s = (CHAR *) buf2;
> + memset (s, 65, page_size);
I think this needs to use wmemset for the WIDE case, see
wcsmbs/test-wcsnlen.c.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v2] test-strnlen.c: Check that strnlen won't go beyond the maximum length
2021-03-27 17:51 ` Florian Weimer
@ 2021-03-27 18:09 ` H.J. Lu
2021-03-27 18:34 ` Florian Weimer
0 siblings, 1 reply; 5+ messages in thread
From: H.J. Lu @ 2021-03-27 18:09 UTC (permalink / raw)
To: Florian Weimer; +Cc: H.J. Lu via Libc-alpha
[-- Attachment #1: Type: text/plain, Size: 1335 bytes --]
On Sat, Mar 27, 2021 at 10:51 AM Florian Weimer <fw@deneb.enyo.de> wrote:
>
> * H. J. Lu via Libc-alpha:
>
> > Run strnlen tests on strings without the null byte around the page
> > boundary.
> > ---
> > string/test-strnlen.c | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/string/test-strnlen.c b/string/test-strnlen.c
> > index 61eb521dc1..a49d93afa2 100644
> > --- a/string/test-strnlen.c
> > +++ b/string/test-strnlen.c
> > @@ -196,6 +196,31 @@ do_page_tests (void)
> > }
> > }
> >
> > +/* Tests meant to unveil fail on implementation that does not access bytes
> > + without the null character around the page boundary accordingly. */
>
> I don't understand the comment. Based on it, I would have expected a
> null byte at the page boundary, which is incorrectly ignored by the
> implementation.
It places strings ending at page boundary without the null byte. If an
implementation goes beyond EXP_LEN, it will trigger the segfault.
> > +static void
> > +do_page_2_tests (void)
> > +{
> > + size_t i, exp_len, offset;
> > + size_t last_offset = page_size / sizeof (CHAR);
> > +
> > + CHAR *s = (CHAR *) buf2;
> > + memset (s, 65, page_size);
>
> I think this needs to use wmemset for the WIDE case, see
> wcsmbs/test-wcsnlen.c.
Fixed.
Here is the v2 patch.
--
H.J.
[-- Attachment #2: v2-0001-test-strnlen.c-Check-that-strnlen-won-t-go-beyond.patch --]
[-- Type: text/x-patch, Size: 1605 bytes --]
From c5d32deca0a024784fa3d9743ddffe38b567ec8c Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sat, 27 Mar 2021 09:06:39 -0700
Subject: [PATCH v2] test-strnlen.c: Check that strnlen won't go beyond the
maximum length
Place strings ending at page boundary without the null byte. If an
implementation goes beyond EXP_LEN, it will trigger the segfault.
---
string/test-strnlen.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/string/test-strnlen.c b/string/test-strnlen.c
index 0293acbc71..d70faa26ab 100644
--- a/string/test-strnlen.c
+++ b/string/test-strnlen.c
@@ -198,6 +198,35 @@ do_page_tests (void)
}
}
+/* Tests meant to unveil fail on implementations that access bytes
+ beyond the maxium length. */
+
+static void
+do_page_2_tests (void)
+{
+ size_t i, exp_len, offset;
+ size_t last_offset = page_size / sizeof (CHAR);
+
+ CHAR *s = (CHAR *) buf2;
+ MEMSET (s, 65, last_offset);
+
+ /* Place short strings ending at page boundary without the null
+ byte. */
+ offset = last_offset;
+ for (i = 0; i < 128; i++)
+ {
+ /* Decrease offset to stress several sizes and alignments. */
+ offset--;
+ exp_len = last_offset - offset;
+ FOR_EACH_IMPL (impl, 0)
+ {
+ /* If an implementation goes beyond EXP_LEN, it will trigger
+ the segfault. */
+ do_one_test (impl, (CHAR *) (s + offset), exp_len, exp_len);
+ }
+ }
+}
+
int
test_main (void)
{
@@ -244,6 +273,7 @@ test_main (void)
do_random_tests ();
do_page_tests ();
+ do_page_2_tests ();
return ret;
}
--
2.30.2
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] test-strnlen.c: Check that strnlen won't go beyond the maximum length
2021-03-27 18:09 ` [PATCH v2] test-strnlen.c: " H.J. Lu
@ 2021-03-27 18:34 ` Florian Weimer
2022-01-27 17:09 ` H.J. Lu
0 siblings, 1 reply; 5+ messages in thread
From: Florian Weimer @ 2021-03-27 18:34 UTC (permalink / raw)
To: H.J. Lu via Libc-alpha
* H. J. Lu via Libc-alpha:
> From: "H.J. Lu" <hjl.tools@gmail.com>
> Date: Sat, 27 Mar 2021 09:06:39 -0700
> Subject: [PATCH v2] test-strnlen.c: Check that strnlen won't go beyond the
> maximum length
>
> Place strings ending at page boundary without the null byte. If an
> implementation goes beyond EXP_LEN, it will trigger the segfault.
> ---
> string/test-strnlen.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/string/test-strnlen.c b/string/test-strnlen.c
> index 0293acbc71..d70faa26ab 100644
> --- a/string/test-strnlen.c
> +++ b/string/test-strnlen.c
> @@ -198,6 +198,35 @@ do_page_tests (void)
> }
> }
>
> +/* Tests meant to unveil fail on implementations that access bytes
> + beyond the maxium length. */
> +
> +static void
> +do_page_2_tests (void)
> +{
> + size_t i, exp_len, offset;
> + size_t last_offset = page_size / sizeof (CHAR);
> +
> + CHAR *s = (CHAR *) buf2;
> + MEMSET (s, 65, last_offset);
> +
> + /* Place short strings ending at page boundary without the null
> + byte. */
> + offset = last_offset;
> + for (i = 0; i < 128; i++)
> + {
> + /* Decrease offset to stress several sizes and alignments. */
> + offset--;
> + exp_len = last_offset - offset;
> + FOR_EACH_IMPL (impl, 0)
> + {
> + /* If an implementation goes beyond EXP_LEN, it will trigger
> + the segfault. */
> + do_one_test (impl, (CHAR *) (s + offset), exp_len, exp_len);
> + }
> + }
> +}
Thanks, looks good. The comments and the commit message are much
clearer now.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] test-strnlen.c: Check that strnlen won't go beyond the maximum length
2021-03-27 18:34 ` Florian Weimer
@ 2022-01-27 17:09 ` H.J. Lu
0 siblings, 0 replies; 5+ messages in thread
From: H.J. Lu @ 2022-01-27 17:09 UTC (permalink / raw)
To: Florian Weimer, Libc-stable Mailing List; +Cc: H.J. Lu via Libc-alpha
On Sat, Mar 27, 2021 at 11:34 AM Florian Weimer <fw@deneb.enyo.de> wrote:
>
> * H. J. Lu via Libc-alpha:
>
> > From: "H.J. Lu" <hjl.tools@gmail.com>
> > Date: Sat, 27 Mar 2021 09:06:39 -0700
> > Subject: [PATCH v2] test-strnlen.c: Check that strnlen won't go beyond the
> > maximum length
> >
> > Place strings ending at page boundary without the null byte. If an
> > implementation goes beyond EXP_LEN, it will trigger the segfault.
> > ---
> > string/test-strnlen.c | 30 ++++++++++++++++++++++++++++++
> > 1 file changed, 30 insertions(+)
> >
> > diff --git a/string/test-strnlen.c b/string/test-strnlen.c
> > index 0293acbc71..d70faa26ab 100644
> > --- a/string/test-strnlen.c
> > +++ b/string/test-strnlen.c
> > @@ -198,6 +198,35 @@ do_page_tests (void)
> > }
> > }
> >
> > +/* Tests meant to unveil fail on implementations that access bytes
> > + beyond the maxium length. */
> > +
> > +static void
> > +do_page_2_tests (void)
> > +{
> > + size_t i, exp_len, offset;
> > + size_t last_offset = page_size / sizeof (CHAR);
> > +
> > + CHAR *s = (CHAR *) buf2;
> > + MEMSET (s, 65, last_offset);
> > +
> > + /* Place short strings ending at page boundary without the null
> > + byte. */
> > + offset = last_offset;
> > + for (i = 0; i < 128; i++)
> > + {
> > + /* Decrease offset to stress several sizes and alignments. */
> > + offset--;
> > + exp_len = last_offset - offset;
> > + FOR_EACH_IMPL (impl, 0)
> > + {
> > + /* If an implementation goes beyond EXP_LEN, it will trigger
> > + the segfault. */
> > + do_one_test (impl, (CHAR *) (s + offset), exp_len, exp_len);
> > + }
> > + }
> > +}
>
> Thanks, looks good. The comments and the commit message are much
> clearer now.
I am backporting this to release branches.
--
H.J.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-03-27 16:24 [PATCH] Check that strnlen won't go beyond the maximum length H.J. Lu
2021-03-27 17:51 ` Florian Weimer
2021-03-27 18:09 ` [PATCH v2] test-strnlen.c: " H.J. Lu
2021-03-27 18:34 ` Florian Weimer
2022-01-27 17:09 ` H.J. Lu
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