diff mbox series

[17/20] Fix missing NUL terminator in stdio-common/scanf13 test

Message ID 40002e888f5b950c07b0bff781f151771fcd0f10.1666877952.git.szabolcs.nagy@arm.com
State New
Headers show
Series patches from the morello port | expand

Commit Message

Szabolcs Nagy Oct. 27, 2022, 3:33 p.m. UTC 
sscanf is only defined on nul terminated string input, but '\0' was
missing in this test which caused _IO_str_init_static_internal to
read OOB on the stack when computing the bounds of the string.
---
 stdio-common/scanf13.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Florian Weimer Oct. 28, 2022, 5:44 a.m. UTC | #1 
* Szabolcs Nagy via Libc-alpha:

> sscanf is only defined on nul terminated string input, but '\0' was
> missing in this test which caused _IO_str_init_static_internal to
> read OOB on the stack when computing the bounds of the string.
> ---
>  stdio-common/scanf13.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/stdio-common/scanf13.c b/stdio-common/scanf13.c
> index 720224aa05..60aa62a26f 100644
> --- a/stdio-common/scanf13.c
> +++ b/stdio-common/scanf13.c
> @@ -67,6 +67,7 @@ main (void)
>    buf[2049] = 0x84;
>    buf[2058] = '\t';
>    buf[2059] = 'a';
> +  buf[sizeof (buf) - 1] = '\0';
>    if (sscanf (buf, "%ms%mc", &sp1, &sp2) != 2)
>      FAIL ();
>    else

We want this test to be correct (see bug 17577), but for now this is the
right change.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

Thanks,
Florian
diff mbox series

Patch

diff --git a/stdio-common/scanf13.c b/stdio-common/scanf13.c
index 720224aa05..60aa62a26f 100644
--- a/stdio-common/scanf13.c
+++ b/stdio-common/scanf13.c
@@ -67,6 +67,7 @@  main (void)
   buf[2049] = 0x84;
   buf[2058] = '\t';
   buf[2059] = 'a';
+  buf[sizeof (buf) - 1] = '\0';
   if (sscanf (buf, "%ms%mc", &sp1, &sp2) != 2)
     FAIL ();
   else