]> git.ipfire.org Git - thirdparty/glibc.git/commitdiff
gconv: Do not emit spurious NUL character in ISO-2022-JP-3 (bug 28524)
authorNikita Popov <npv1310@gmail.com>
Tue, 2 Nov 2021 08:21:42 +0000 (13:21 +0500)
committerAurelien Jarno <aurelien@aurel32.net>
Sat, 4 Dec 2021 23:29:46 +0000 (00:29 +0100)
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>
(cherry picked from commit ff012870b2c02a62598c04daa1e54632e020fd7d)

NEWS
iconvdata/Makefile
iconvdata/bug-iconv15.c [new file with mode: 0644]
iconvdata/iso-2022-jp-3.c

diff --git a/NEWS b/NEWS
index 581e6b2ac1439597807f5d55018b93ae45925982..b29826f4f591fef222ac9b34098423fd8a5931bb 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -23,6 +23,7 @@ The following bugs are resolved with this release:
   [26932] libc: sh: Multiple floating point functions defined as stubs only
   [27130] "rep movsb" performance issue
   [27177] GLIBC_TUNABLES=glibc.cpu.x86_ibt=on:glibc.cpu.x86_shstk=on doesn't work
+  [28524] Conversion from ISO-2022-JP-3 with iconv may emit spurious NULs
   [28607] Masked signals are delivered on thread exit
 
 Version 2.32
index 4eef07557e5b67ca8da6acb307f5e1cdba328a53..b67b4feeb49edec150d54eb41610a2c5ad1825a7 100644 (file)
@@ -1,4 +1,5 @@
 # Copyright (C) 1997-2020 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
@@ -324,6 +325,8 @@ $(objpfx)bug-iconv12.out: $(objpfx)gconv-modules \
                          $(addprefix $(objpfx),$(modules.so))
 $(objpfx)bug-iconv14.out: $(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 $(objpfx)gconv-modules \
                         $(addprefix $(objpfx),$(modules.so)) \
diff --git a/iconvdata/bug-iconv15.c b/iconvdata/bug-iconv15.c
new file mode 100644 (file)
index 0000000..cc04bd0
--- /dev/null
@@ -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 62cbc54a110ab1f98861562309cd4d5f83c37099..c7b470db618657318cd41c595517b46f601eb6f6 100644 (file)
@@ -1,5 +1,6 @@
 /* Conversion module for ISO-2022-JP-3.
    Copyright (C) 1998-2020 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                                                                   \
        {                                                                     \