iconv: Fix iconv functions not following symlinks [BZ #32339]

On some file systems iconv do not follow symlinks.  This happens because
read_conf_file() function's directory traversal loop reject symbolic
links and then lstat64() call do not follow symlinks.

This commit fixes the directory traversal loop to accept symbolic links
and then follow the link using stat64().

The test works by creating a temporary directory and placing a symbolic
link inside it that points to a configuration file.  It then runs
iconvconfig on this directory.

The test passes if iconvconfig successfully follows the symlink and
generates the cache correctly, confirming that the directory traversal
logic now properly handles symbolic links.

Signed-off-by: Avinal Kumar <avinal.xlvii@gmail.com>
Co-authored-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

diff --git a/iconv/Makefile b/iconv/Makefile
index 9a94a41ba4ba583e8ddbb7d09d64cc3b1dcf93f8..672126d45263c5472a5c5de3c17e5524d29f5284 100644 (file)
--- a/iconv/Makefile
+++ b/iconv/Makefile
@@ -85,6 +85,7 @@ tests-special += \
        $(objpfx)tst-iconv_prog-buffer-tiny.out \
        $(objpfx)tst-iconv_prog-buffer.out \
        $(objpfx)tst-iconv_prog.out \
+       $(objpfx)tst-iconvconfig.out \
        $(objpfx)tst-translit-mchar.out \
        # tests-special
 endif
@@ -164,3 +165,8 @@ $(objpfx)tst-iconv_prog-buffer-large.out: \
   tst-iconv_prog-buffer.sh $(objpfx)iconv_prog
        $(BASH) $< $(common-objdir) '$(run-program-prefix)' '' '22' > $@; \
        $(evaluate-test)
+
+$(objpfx)tst-iconvconfig.out: tst-iconvconfig.sh $(objpfx)iconvconfig
+       $(BASH) $< $(common-objdir) '$(test-wrapper-env)' \
+               '$(run-program-env)' > $@; \
+    $(evaluate-test)

diff --git a/iconv/gconv_parseconfdir.h b/iconv/gconv_parseconfdir.h
index a7ebfd80ccaee6a1f9e0268d99f6ebc62de0b0e7..31f8f1c4214794d66ee60add75fa32ea61821168 100644 (file)
--- a/iconv/gconv_parseconfdir.h
+++ b/iconv/gconv_parseconfdir.h
@@ -33,9 +33,10 @@
 # define closedir __closedir
 # define mempcpy __mempcpy
 # define struct_stat64 struct __stat64_t64
-# define lstat64 __lstat64_time64
+# define stat64_impl __stat64_time64
 # define feof_unlocked __feof_unlocked
 #else
+# define stat64_impl stat64
 # define struct_stat64 struct stat64
 #endif
 
@@ -151,7 +152,8 @@ gconv_parseconfdir (const char *prefix, const char *dir, size_t dir_len)
       struct dirent64 *ent;
       while ((ent = readdir64 (confdir)) != NULL)
        {
-         if (ent->d_type != DT_REG && ent->d_type != DT_UNKNOWN)
+         if (ent->d_type != DT_REG && ent->d_type != DT_UNKNOWN
+             && ent->d_type != DT_LNK)
            continue;
 
          size_t len = strlen (ent->d_name);
@@ -166,7 +168,7 @@ gconv_parseconfdir (const char *prefix, const char *dir, size_t dir_len)
                continue;
 
              if (ent->d_type != DT_UNKNOWN
-                 || (lstat64 (conf, &st) != -1 && S_ISREG (st.st_mode)))
+                 || (stat64_impl (conf, &st) != -1 && S_ISREG (st.st_mode)))
                found |= read_conf_file (conf, dir, dir_len);
 
              free (conf);

diff --git a/iconv/tst-iconvconfig.sh b/iconv/tst-iconvconfig.sh
new file mode 100755 (executable)
index 0000000..0b16b17
--- /dev/null
+++ b/iconv/tst-iconvconfig.sh
@@ -0,0 +1,48 @@
+#!/bin/bash
+# Check if iconvconfig correctly handle config links (BZ 32339)
+# Copyright (C) 2025 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/>.
+
+set -e
+
+build_dir=$1
+test_wrapper_env="$2"
+run_program_env="$3"
+
+# We have to have some directories in the library path.
+LIBPATH=$build_dir:$build_dir/iconvdata
+
+ICONVCONFIG="
+$build_dir/elf/ld.so --library-path $LIBPATH $build_dir/iconv/iconvconfig
+"
+
+ICONVCONFIG="$test_wrapper_env $run_program_env $ICONVCONFIG"
+
+TIMEOUTFACTOR=${TIMEOUTFACTOR:-1}
+
+tmpdir=$(mktemp -d $build_dir/iconv/tst-iconvconfig.XXXXXX)
+#trap 'rm -fr $tmpdir' 0 1 2 3 15 EXIT
+
+touch $tmpdir/gconv-modules-extra.conf
+mkdir $tmpdir/gconv-modules.d
+cd $tmpdir/gconv-modules.d && ln -s ../gconv-modules-extra.conf . && cd -
+
+$ICONVCONFIG --nostdlib $tmpdir -o $tmpdir/gconv-modules.cache
+
+[ ! -e $tmpdir/tmpdir/gconv-modules.cache ] || exit 1
+
+exit 0