| From ff012870b2c02a62598c04daa1e54632e020fd7d Mon Sep 17 00:00:00 2001 |
| From: Nikita Popov <npv1310@gmail.com> |
| Date: Tue, 2 Nov 2021 13:21:42 +0500 |
| Subject: [PATCH] gconv: Do not emit spurious NUL character in ISO-2022-JP-3 |
| (bug 28524) |
| |
| Bugfix 27256 has introduced another issue: |
| In conversion from ISO-2022-JP-3 encoding, it is possible |
| to force iconv to emit extra NUL character on internal state reset. |
| To do this, it is sufficient to feed iconv with escape sequence |
| which switches active character set. |
| The simplified check 'data->__statep->__count != ASCII_set' |
| introduced by the aforementioned bugfix picks that case and |
| behaves as if '\0' character has been queued thus emitting it. |
| |
| To eliminate this issue, these steps are taken: |
| * Restore original condition |
| '(data->__statep->__count & ~7) != ASCII_set'. |
| It is necessary since bits 0-2 may contain |
| number of buffered input characters. |
| * Check that queued character is not NUL. |
| Similar step is taken for main conversion loop. |
| |
| Bundled test case follows following logic: |
| * Try to convert ISO-2022-JP-3 escape sequence |
| switching active character set |
| * Reset internal state by providing NULL as input buffer |
| * Ensure that nothing has been converted. |
| |
| Signed-off-by: Nikita Popov <npv1310@gmail.com> |
| |
| CVE: CVE-2021-43396 |
| Upstream-Status: Backport [ff012870b2c02a62598c04daa1e54632e020fd7d] |
| --- |
| iconvdata/Makefile | 5 +++- |
| iconvdata/bug-iconv15.c | 60 +++++++++++++++++++++++++++++++++++++++ |
| iconvdata/iso-2022-jp-3.c | 28 ++++++++++++------ |
| 3 files changed, 84 insertions(+), 9 deletions(-) |
| create mode 100644 iconvdata/bug-iconv15.c |
| |
| Index: git/iconvdata/Makefile |
| =================================================================== |
| --- git.orig/iconvdata/Makefile |
| +++ git/iconvdata/Makefile |
| @@ -1,4 +1,5 @@ |
| # Copyright (C) 1997-2021 Free Software Foundation, Inc. |
| +# Copyright (C) The GNU Toolchain Authors. |
| # This file is part of the GNU C Library. |
| |
| # The GNU C Library is free software; you can redistribute it and/or |
| @@ -74,7 +75,7 @@ ifeq (yes,$(build-shared)) |
| tests = bug-iconv1 bug-iconv2 tst-loading tst-e2big tst-iconv4 bug-iconv4 \ |
| tst-iconv6 bug-iconv5 bug-iconv6 tst-iconv7 bug-iconv8 bug-iconv9 \ |
| bug-iconv10 bug-iconv11 bug-iconv12 tst-iconv-big5-hkscs-to-2ucs4 \ |
| - bug-iconv13 bug-iconv14 |
| + bug-iconv13 bug-iconv14 bug-iconv15 |
| ifeq ($(have-thread-library),yes) |
| tests += bug-iconv3 |
| endif |
| @@ -327,6 +328,8 @@ $(objpfx)bug-iconv12.out: $(addprefix $( |
| $(addprefix $(objpfx),$(modules.so)) |
| $(objpfx)bug-iconv14.out: $(addprefix $(objpfx), $(gconv-modules)) \ |
| $(addprefix $(objpfx),$(modules.so)) |
| +$(objpfx)bug-iconv15.out: $(addprefix $(objpfx), $(gconv-modules)) \ |
| + $(addprefix $(objpfx),$(modules.so)) |
| |
| $(objpfx)iconv-test.out: run-iconv-test.sh \ |
| $(addprefix $(objpfx), $(gconv-modules)) \ |
| Index: git/iconvdata/bug-iconv15.c |
| =================================================================== |
| --- /dev/null |
| +++ git/iconvdata/bug-iconv15.c |
| @@ -0,0 +1,60 @@ |
| +/* Bug 28524: Conversion from ISO-2022-JP-3 with iconv |
| + may emit spurious NUL character on state reset. |
| + Copyright (C) The GNU Toolchain Authors. |
| + 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 <stddef.h> |
| +#include <iconv.h> |
| +#include <support/check.h> |
| + |
| +static int |
| +do_test (void) |
| +{ |
| + char in[] = "\x1b(I"; |
| + char *inbuf = in; |
| + size_t inleft = sizeof (in) - 1; |
| + char out[1]; |
| + char *outbuf = out; |
| + size_t outleft = sizeof (out); |
| + iconv_t cd; |
| + |
| + cd = iconv_open ("UTF8", "ISO-2022-JP-3"); |
| + TEST_VERIFY_EXIT (cd != (iconv_t) -1); |
| + |
| + /* First call to iconv should alter internal state. |
| + Now, JISX0201_Kana_set is selected and |
| + state value != ASCII_set. */ |
| + TEST_VERIFY (iconv (cd, &inbuf, &inleft, &outbuf, &outleft) != (size_t) -1); |
| + |
| + /* No bytes should have been added to |
| + the output buffer at this point. */ |
| + TEST_VERIFY (outbuf == out); |
| + TEST_VERIFY (outleft == sizeof (out)); |
| + |
| + /* Second call shall emit spurious NUL character in unpatched glibc. */ |
| + TEST_VERIFY (iconv (cd, NULL, NULL, &outbuf, &outleft) != (size_t) -1); |
| + |
| + /* No characters are expected to be produced. */ |
| + TEST_VERIFY (outbuf == out); |
| + TEST_VERIFY (outleft == sizeof (out)); |
| + |
| + TEST_VERIFY_EXIT (iconv_close (cd) != -1); |
| + |
| + return 0; |
| +} |
| + |
| +#include <support/test-driver.c> |
| Index: git/iconvdata/iso-2022-jp-3.c |
| =================================================================== |
| --- git.orig/iconvdata/iso-2022-jp-3.c |
| +++ git/iconvdata/iso-2022-jp-3.c |
| @@ -1,5 +1,6 @@ |
| /* Conversion module for ISO-2022-JP-3. |
| Copyright (C) 1998-2021 Free Software Foundation, Inc. |
| + Copyright (C) The GNU Toolchain Authors. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998, |
| and Bruno Haible <bruno@clisp.org>, 2002. |
| @@ -81,20 +82,31 @@ enum |
| the output state to the initial state. This has to be done during the |
| flushing. */ |
| #define EMIT_SHIFT_TO_INIT \ |
| - if (data->__statep->__count != ASCII_set) \ |
| + if ((data->__statep->__count & ~7) != ASCII_set) \ |
| { \ |
| if (FROM_DIRECTION) \ |
| { \ |
| - if (__glibc_likely (outbuf + 4 <= outend)) \ |
| + uint32_t ch = data->__statep->__count >> 6; \ |
| + \ |
| + if (__glibc_unlikely (ch != 0)) \ |
| { \ |
| - /* Write out the last character. */ \ |
| - *((uint32_t *) outbuf) = data->__statep->__count >> 6; \ |
| - outbuf += sizeof (uint32_t); \ |
| - data->__statep->__count = ASCII_set; \ |
| + if (__glibc_likely (outbuf + 4 <= outend)) \ |
| + { \ |
| + /* Write out the last character. */ \ |
| + put32u (outbuf, ch); \ |
| + outbuf += 4; \ |
| + data->__statep->__count &= 7; \ |
| + data->__statep->__count |= ASCII_set; \ |
| + } \ |
| + else \ |
| + /* We don't have enough room in the output buffer. */ \ |
| + status = __GCONV_FULL_OUTPUT; \ |
| } \ |
| else \ |
| - /* We don't have enough room in the output buffer. */ \ |
| - status = __GCONV_FULL_OUTPUT; \ |
| + { \ |
| + data->__statep->__count &= 7; \ |
| + data->__statep->__count |= ASCII_set; \ |
| + } \ |
| } \ |
| else \ |
| { \ |