commit ae4d44b1d501421ad9a3af95279b8f4d1546f1ce
Author: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date:   Tue Sep 3 14:58:33 2024 -0400

    libio: Attempt wide backup free only for non-legacy code
    
    _wide_data and _mode are not available in legacy code, so do not attempt
    to free the wide backup buffer in legacy code.
    
    Resolves: BZ #32137 and BZ #27821
    
    Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
    Reviewed-by: Florian Weimer <fweimer@redhat.com>

diff --git a/libio/genops.c b/libio/genops.c
index b5fc53fd1ef6e911..99ef9d03505f3238 100644
--- a/libio/genops.c
+++ b/libio/genops.c
@@ -799,7 +799,7 @@ _IO_unbuffer_all (void)
       /* Free up the backup area if it was ever allocated.  */
       if (_IO_have_backup (fp))
 	_IO_free_backup_area (fp);
-      if (fp->_mode > 0 && _IO_have_wbackup (fp))
+      if (!legacy && fp->_mode > 0 && _IO_have_wbackup (fp))
 	_IO_free_wbackup_area (fp);
 
       if (! (fp->_flags & _IO_UNBUFFERED)