diff options
Diffstat (limited to 'libio-Ensure-output-buffer-for-wchars-bug-28828.patch')
| -rw-r--r-- | libio-Ensure-output-buffer-for-wchars-bug-28828.patch | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/libio-Ensure-output-buffer-for-wchars-bug-28828.patch b/libio-Ensure-output-buffer-for-wchars-bug-28828.patch new file mode 100644 index 0000000..6cb10d5 --- /dev/null +++ b/libio-Ensure-output-buffer-for-wchars-bug-28828.patch @@ -0,0 +1,110 @@ +From edc696a73a7cb07b1aa68792a845a98d036ee7eb Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Jos=C3=A9=20Bollo?= <jobol@nonadev.net> +Date: Tue, 8 Mar 2022 09:58:16 +0100 +Subject: [PATCH] libio: Ensure output buffer for wchars (bug #28828) + +The _IO_wfile_overflow does not check if the write pointer for wide +data is valid before access, different than _IO_file_overflow. This +leads to crash on some cases, as described by bug 28828. + +The minimal sequence to produce the crash was: + + #include <stdio.h> + #include <wchar.h> + int main (int ac, char **av) + { + setvbuf (stdout, NULL, _IOLBF, 0); + fgetwc (stdin); + fputwc (10, stdout); /*CRASH HERE!*/ + return 0; + } + +The "fgetwc(stdin);" is necessary since it triggers the bug by setting +the flag _IO_CURRENTLY_PUTTING on stdout indirectly (file wfileops.c, +function _IO_wfile_underflow, line 213). + +Signed-off-by: Jose Bollo <jobol@nonadev.net> +--- + libio/Makefile | 2 +- + libio/tst-bz28828.c | 32 ++++++++++++++++++++++++++++++++ + libio/tst-bz28828.input | 1 + + libio/wfileops.c | 3 ++- + 4 files changed, 36 insertions(+), 2 deletions(-) + create mode 100644 libio/tst-bz28828.c + create mode 100644 libio/tst-bz28828.input + +diff --git a/libio/Makefile b/libio/Makefile +index 0e5f348..e973877 100644 +--- a/libio/Makefile ++++ b/libio/Makefile +@@ -66,7 +66,7 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \ + tst-fwrite-error tst-ftell-partial-wide tst-ftell-active-handler \ + tst-ftell-append tst-fputws tst-bz22415 tst-fgetc-after-eof \ + tst-sprintf-ub tst-sprintf-chk-ub tst-bz24051 tst-bz24153 \ +- tst-wfile-sync ++ tst-wfile-sync tst-bz28828 + + tests-internal = tst-vtables tst-vtables-interposed + +diff --git a/libio/tst-bz28828.c b/libio/tst-bz28828.c +new file mode 100644 +index 0000000..638a6e2 +--- /dev/null ++++ b/libio/tst-bz28828.c +@@ -0,0 +1,32 @@ ++/* Unit test for BZ#28828. ++ Copyright (C) 2022 Free Software Foundation, Inc. ++ This file is part of the GNU C Library. ++ ++ The GNU C Library is free software; you can redistribute it and/or ++ modify it under the terms of the GNU Lesser General Public ++ License as published by the Free Software Foundation; either ++ version 2.1 of the License, or (at your option) any later version. ++ ++ The GNU C Library is distributed in the hope that it will be useful, ++ but WITHOUT ANY WARRANTY; without even the implied warranty of ++ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ++ Lesser General Public License for more details. ++ ++ You should have received a copy of the GNU Lesser General Public ++ License along with the GNU C Library; if not, see ++ <https://www.gnu.org/licenses/>. */ ++ ++#include <support/xstdio.h> ++#include <support/check.h> ++#include <wchar.h> ++ ++static int ++do_test (void) ++{ ++ setvbuf (stdout, NULL, _IOLBF, 0); ++ fgetwc (stdin); ++ fputwc (10, stdout); /* It should not crash here. */ ++ return 0; ++} ++ ++#include <support/test-driver.c> +diff --git a/libio/tst-bz28828.input b/libio/tst-bz28828.input +new file mode 100644 +index 0000000..ce01362 +--- /dev/null ++++ b/libio/tst-bz28828.input +@@ -0,0 +1 @@ ++hello +diff --git a/libio/wfileops.c b/libio/wfileops.c +index fb9d45b..b59a988 100644 +--- a/libio/wfileops.c ++++ b/libio/wfileops.c +@@ -412,7 +412,8 @@ _IO_wfile_overflow (FILE *f, wint_t wch) + return WEOF; + } + /* If currently reading or no buffer allocated. */ +- if ((f->_flags & _IO_CURRENTLY_PUTTING) == 0) ++ if ((f->_flags & _IO_CURRENTLY_PUTTING) == 0 ++ || f->_wide_data->_IO_write_base == NULL) + { + /* Allocate a buffer if needed. */ + if (f->_wide_data->_IO_write_base == 0) +-- +1.8.3.1 + |