diff options
Diffstat (limited to 'locale/findlocale.c')
| -rw-r--r-- | locale/findlocale.c | 74 |
1 files changed, 61 insertions, 13 deletions
diff --git a/locale/findlocale.c b/locale/findlocale.c index bbaf708017..22e8b53032 100644 --- a/locale/findlocale.c +++ b/locale/findlocale.c @@ -17,6 +17,7 @@ <http://www.gnu.org/licenses/>. */ #include <assert.h> +#include <errno.h> #include <locale.h> #include <stdlib.h> #include <string.h> @@ -57,6 +58,45 @@ struct loaded_l10nfile *_nl_locale_file_list[__LC_LAST]; const char _nl_default_locale_path[] attribute_hidden = LOCALEDIR; +/* Checks if the name is actually present, that is, not NULL and not + empty. */ +static inline int +name_present (const char *name) +{ + return name != NULL && name[0] != '\0'; +} + +/* Checks that the locale name neither extremely long, nor contains a + ".." path component (to prevent directory traversal). */ +static inline int +valid_locale_name (const char *name) +{ + /* Not set. */ + size_t namelen = strlen (name); + /* Name too long. The limit is arbitrary and prevents stack overflow + issues later. */ + if (__glibc_unlikely (namelen > 255)) + return 0; + /* Directory traversal attempt. */ + static const char slashdot[4] = {'/', '.', '.', '/'}; + if (__glibc_unlikely (memmem (name, namelen, + slashdot, sizeof (slashdot)) != NULL)) + return 0; + if (namelen == 2 && __glibc_unlikely (name[0] == '.' && name [1] == '.')) + return 0; + if (namelen >= 3 + && __glibc_unlikely (((name[0] == '.' + && name[1] == '.' + && name[2] == '/') + || (name[namelen - 3] == '/' + && name[namelen - 2] == '.' + && name[namelen - 1] == '.')))) + return 0; + /* If there is a slash in the name, it must start with one. */ + if (__glibc_unlikely (memchr (name, '/', namelen) != NULL) && name[0] != '/') + return 0; + return 1; +} struct __locale_data * internal_function @@ -65,7 +105,7 @@ _nl_find_locale (const char *locale_path, size_t locale_path_len, { int mask; /* Name of the locale for this category. */ - char *loc_name; + char *loc_name = (char *) *name; const char *language; const char *modifier; const char *territory; @@ -73,31 +113,39 @@ _nl_find_locale (const char *locale_path, size_t locale_path_len, const char *normalized_codeset; struct loaded_l10nfile *locale_file; - if ((*name)[0] == '\0') + if (loc_name[0] == '\0') { /* The user decides which locale to use by setting environment variables. */ - *name = getenv ("LC_ALL"); - if (*name == NULL || (*name)[0] == '\0') - *name = getenv (_nl_category_names.str + loc_name = getenv ("LC_ALL"); + if (!name_present (loc_name)) + loc_name = getenv (_nl_category_names.str + _nl_category_name_idxs[category]); - if (*name == NULL || (*name)[0] == '\0') - *name = getenv ("LANG"); + if (!name_present (loc_name)) + loc_name = getenv ("LANG"); + if (!name_present (loc_name)) + loc_name = (char *) _nl_C_name; } - if (*name == NULL || (*name)[0] == '\0' - || (__builtin_expect (__libc_enable_secure, 0) - && strchr (*name, '/') != NULL)) - *name = (char *) _nl_C_name; + /* We used to fall back to the C locale if the name contains a slash + character '/', but we now check for directory traversal in + valid_locale_name, so this is no longer necessary. */ - if (__builtin_expect (strcmp (*name, _nl_C_name), 1) == 0 - || __builtin_expect (strcmp (*name, _nl_POSIX_name), 1) == 0) + if (__builtin_expect (strcmp (loc_name, _nl_C_name), 1) == 0 + || __builtin_expect (strcmp (loc_name, _nl_POSIX_name), 1) == 0) { /* We need not load anything. The needed data is contained in the library itself. */ *name = (char *) _nl_C_name; return _nl_C[category]; } + else if (!valid_locale_name (loc_name)) + { + __set_errno (EINVAL); + return NULL; + } + + *name = loc_name; /* We really have to load some data. First we try the archive, but only if there was no LOCPATH environment variable specified. */ |