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* [newlib-cygwin] newlocale: fix crash when trying to write to __C_locale
@ 2022-08-12 10:30 Corinna Vinschen
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From: Corinna Vinschen @ 2022-08-12 10:30 UTC (permalink / raw)
To: cygwin-cvs, newlib-cvs
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=85be74f2951968be7fe1979014d6246171ebd123
commit 85be74f2951968be7fe1979014d6246171ebd123
Author: Corinna Vinschen <corinna@vinschen.de>
Date: Thu Aug 11 19:27:48 2022 +0200
newlocale: fix crash when trying to write to __C_locale
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>
Diff:
---
newlib/libc/locale/newlocale.c | 3 ++-
winsup/cygwin/release/3.3.6 | 3 +++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/newlib/libc/locale/newlocale.c b/newlib/libc/locale/newlocale.c
index 0789d5fd9..08f29dbcc 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);
diff --git a/winsup/cygwin/release/3.3.6 b/winsup/cygwin/release/3.3.6
index 364e0cb0d..1da4fa26c 100644
--- a/winsup/cygwin/release/3.3.6
+++ b/winsup/cygwin/release/3.3.6
@@ -39,3 +39,6 @@ Bug Fixes
- Fix a path handling bug that could cause a non-existing file to be
treated as the current directory.
Addresses: https://cygwin.com/pipermail/cygwin/2022-August/252030.html
+
+- Fix a crash in newlocale.
+ Addresses: https://cygwin.com/pipermail/cygwin/2022-August/252043.html
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