From: Corinna Vinschen <corinna@vinschen.de>
To: newlib@sourceware.org
Subject: [PATCH] newlocale: fix crash when trying to write to __C_locale
Date: Thu, 11 Aug 2022 20:00:07 +0200 [thread overview]
Message-ID: <20220811180007.296636-1-corinna@vinschen.de> (raw)
This simple testcase:
locale_t st = newlocale(LC_ALL_MASK, "C", (locale_t)0);
locale_t st2 = newlocale(LC_CTYPE_MASK, "en_US.UTF-8", st);
is sufficient to reproduce a crash in _newlocale_r. After the first call
to newlocale, `st' points to __C_locale, which is const. When using `st'
as locale base in the second call, _newlocale_r tries to set pointers
inside base to NULL. This is bad if base is __C_locale, obviously.
Add a test to avoid trying to overwrite pointer values inside base if
base is __C_locale.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
---
newlib/libc/locale/newlocale.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/newlib/libc/locale/newlocale.c b/newlib/libc/locale/newlocale.c
index 0789d5fd95ec..08f29dbcc0c1 100644
--- a/newlib/libc/locale/newlocale.c
+++ b/newlib/libc/locale/newlocale.c
@@ -188,7 +188,8 @@ _newlocale_r (struct _reent *p, int category_mask, const char *locale,
if (tmp_locale.lc_cat[i].buf == (const void *) -1)
{
tmp_locale.lc_cat[i].buf = base->lc_cat[i].buf;
- base->lc_cat[i].ptr = base->lc_cat[i].buf = NULL;
+ if (base != __get_C_locale ())
+ base->lc_cat[i].ptr = base->lc_cat[i].buf = NULL;
}
#endif /* __HAVE_LOCALE_INFO__ */
_freelocale_r (p, base);
--
2.37.1
reply other threads:[~2022-08-11 18:00 UTC|newest]
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