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Fix leak, broken collation of UTF-8 string in non-UTF8 locale #22963

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merged 10 commits into from
Feb 9, 2025
Merged

Fix leak, broken collation of UTF-8 string in non-UTF8 locale #22963

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9b05ec3
locale.c: White space, comments, cleanup allowed by C99
khwilliamson Jan 29, 2025
e8418ae
locale.c: Remove a Renew() trimming a malloc
khwilliamson Jan 29, 2025
2564e97
mem_collxfrm_: Reorder a few statements
khwilliamson Jan 30, 2025
37b04c4
mem_collxfrm_: Move common code into common macro
khwilliamson Jan 30, 2025
11442c0
memcollxfrm: Refactor some if clauses
khwilliamson Jan 30, 2025
5bbc245
memcollxfrm: Use free_me translating between bytes/UTF-8
khwilliamson Jan 30, 2025
eb5f0c5
memcollxfrm: Fix a memory leak
khwilliamson Jan 30, 2025
16895ec
memcollxfrm: Simplify loop
khwilliamson Jan 30, 2025
6d45438
collxfrm: Add missing length set
khwilliamson Jan 31, 2025
5a61683
run/locale.t: Add test for UTF-8 string non-UTF8 locale
khwilliamson Jan 31, 2025
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285 changes: 145 additions & 140 deletions locale.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9609,6 +9609,8 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
bool utf8 /* Is the input in UTF-8? */
)
{
PERL_ARGS_ASSERT_MEM_COLLXFRM_;

/* mem_collxfrm_() is like strxfrm() but with two important differences.
* First, it handles embedded NULs. Second, it allocates a bit more memory
* than needed for the transformed data itself. The real transformed data
Expand Down Expand Up @@ -9637,11 +9639,18 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
locale_t constructed_locale = (locale_t) 0;
# endif

PERL_ARGS_ASSERT_MEM_COLLXFRM_;

/* Must be NUL-terminated */
assert(*(input_string + len) == '\0');

/* We may have to allocate memory to hold modified versions of the input.
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* Initialize to NULL here, and before any return, free them all. Those
* that do get allocated will be non-NULL then, and get freed */
char * sans_nuls = NULL; /* NULs changed to lowest collating ctrl */
char * sans_highs = NULL; /* >0xFF changed to highest collating byte
for non-UTF8 locales */
void * free_me = NULL; /* some called functions may allocate memory that
this function then is required to free */

if (PL_collxfrm_mult == 0) { /* unknown or bad */
if (PL_collxfrm_base != 0) { /* bad collation => skip */
DEBUG_L(PerlIO_printf(Perl_debug_log,
Expand All @@ -9659,10 +9668,10 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
* otherwise contain that character, but otherwise there may be
* less-than-perfect results with that character and NUL. This is
* unavoidable unless we replace strxfrm with our own implementation. */

if (UNLIKELY(s_strlen < len)) { /* Only execute if there is an embedded
NUL */
char * e = s + len;
char * sans_nuls;
STRLEN sans_nuls_len;
int try_non_controls;
char this_replacement_char[] = "?\0"; /* Room for a two-byte string,
Expand Down Expand Up @@ -9825,148 +9834,141 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
len = strlen(s);
} /* End of replacing NULs */

/* Make sure the UTF8ness of the string and locale match */
if (utf8 != PL_in_utf8_COLLATE_locale) {
/* XXX convert above Unicode to 10FFFF? */
const char * const t = s; /* Temporary so we can later find where the
input was */
if (! utf8) {

/* Here they don't match. Change the string's to be what the locale is
* expecting */

if (! utf8) { /* locale is UTF-8, but input isn't; upgrade the input */
s = (char *) bytes_to_utf8((const U8 *) s, &len);
/* When the locale is UTF-8, strxfrm() is expecting a UTF-8 string.
* Here, the string isn't. Convert it to be so. */
if (PL_in_utf8_COLLATE_locale) {
s = (char *) bytes_to_utf8_free_me((const U8 *) s, &len, &free_me);
utf8 = TRUE;
}
else { /* locale is not UTF-8; but input is; downgrade the input */

s = (char *) bytes_from_utf8((const U8 *) s, &len, &utf8);

/* If the downgrade was successful we are done, but if the input
* contains things that require UTF-8 to represent, have to do
* damage control ... */
if (UNLIKELY(utf8)) {

/* What we do is construct a non-UTF-8 string with
* 1) the characters representable by a single byte converted
* to be so (if necessary);
* 2) and the rest converted to collate the same as the
* highest collating representable character. That makes
* them collate at the end. This is similar to how we
* handle embedded NULs, but we use the highest collating
* code point instead of the smallest. Like the NUL case,
* this isn't perfect, but is the best we can reasonably
* do. Every above-255 code point will sort the same as
* the highest-sorting 0-255 code point. If that code
* point can combine in a sequence with some other code
* points for weight calculations, us changing something to
* be it can adversely affect the results. But in most
* cases, it should work reasonably. And note that this is
* really an illegal situation: using code points above 255
* on a locale where only 0-255 are valid. If two strings
* sort entirely equal, then the sort order for the
* above-255 code points will be in code point order. */

utf8 = FALSE;

/* If we haven't calculated the code point with the maximum
* collating order for this locale, do so now */
if (! PL_strxfrm_max_cp) {
int j;

/* The current transformed string that collates the
* highest (except it also includes the prefixed collation
* index. */
char * cur_max_x = NULL;

/* Look through all legal code points (NUL isn't) */
for (j = 1; j < 256; j++) {
char * x;
STRLEN x_len;
char cur_source[] = { '\0', '\0' };

/* Create a 1-char string of the current code point */
cur_source[0] = (char) j;

/* Then transform it */
x = mem_collxfrm_(cur_source, 1, &x_len, FALSE);

/* If something went wrong (which it shouldn't), just
* ignore this code point */
if (! x) {
continue;
}

/* If this character's transformation is higher than
* the current highest, this one becomes the highest */
if ( cur_max_x == NULL
|| strGT(x + COLLXFRM_HDR_LEN,
cur_max_x + COLLXFRM_HDR_LEN))
{
PL_strxfrm_max_cp = j;
Safefree(cur_max_x);
cur_max_x = x;
}
else {
Safefree(x);
}
/* We are ready to call strxfrm() */
}
else if (! PL_in_utf8_COLLATE_locale) {

/* Here, the string is UTF-8, but the locale isn't. strxfrm() is
* expecting a non-UTF-8 string. Convert the string to bytes. If
* that succeeds, we are ready to call strxfrm() */
utf8 = FALSE;
if (UNLIKELY(! utf8_to_bytes_new_pv((const U8 **) &s, &len, &free_me)))
{
/* But here, it didn't succeed; have to do damage control ...
*
* What we do is construct a non-UTF-8 string with
* 1) the characters representable by a single byte converted to
* be so (if not already);
* 2) and the rest converted to collate the same as the highest
* collating representable character. That makes them collate
* at the end. This is similar to how we handle embedded NULs,
* but we use the highest collating code point instead of the
* smallest. Like the NUL case, this isn't perfect, but is the
* best we can reasonably do. Every above-255 code point will
* sort the same as the highest-sorting 0-255 code point. If
* that code point can combine in a sequence with some other
* code points for weight calculations, us changing something
* to be it can adversely affect the results. But in most
* cases, it should work reasonably. And note that this is
* really an illegal situation: using code points above 255 on
* a locale where only 0-255 are valid. If two strings sort
* entirely equal, then the sort order for the above-255 code
* points will be in code point order.
*
* If we haven't calculated the code point with the maximum
* collating order for this locale, do so now */
if (! PL_strxfrm_max_cp) {
int j;

/* The current transformed string that collates the
* highest (except it also includes the prefixed collation
* index. */
char * cur_max_x = NULL;

/* Look through all legal code points (NUL isn't) */
for (j = 1; j < 256; j++) {
char * x;
STRLEN x_len;
char cur_source[] = { '\0', '\0' };

/* Create a 1-char string of the current code point */
cur_source[0] = (char) j;

/* Then transform it */
x = mem_collxfrm_(cur_source, 1, &x_len, FALSE);

/* If something went wrong (which it shouldn't), just
* ignore this code point */
if (! x) {
continue;
}

if (! cur_max_x) {
DEBUG_L(PerlIO_printf(Perl_debug_log,
"mem_collxfrm_: Couldn't find any character to"
" replace above-Latin1 chars in locale %s with",
PL_collation_name));
goto bad;
/* If this character's transformation is higher than
* the current highest, this one becomes the highest */
if ( cur_max_x == NULL
|| strGT(x + COLLXFRM_HDR_LEN,
cur_max_x + COLLXFRM_HDR_LEN))
{
PL_strxfrm_max_cp = j;
Safefree(cur_max_x);
cur_max_x = x;
}
else {
Safefree(x);
}
}

if (! cur_max_x) {
DEBUG_L(PerlIO_printf(Perl_debug_log,
"mem_collxfrm_: highest 1-byte collating character"
" in locale %s is 0x%02X\n",
PL_collation_name,
PL_strxfrm_max_cp));

Safefree(cur_max_x);
"mem_collxfrm_: Couldn't find any character to"
" replace above-Latin1 chars in locale %s with",
PL_collation_name));
goto bad;
}

/* Here we know which legal code point collates the highest.
* We are ready to construct the non-UTF-8 string. The length
* will be at least 1 byte smaller than the input string
* (because we changed at least one 2-byte character into a
* single byte), but that is eaten up by the trailing NUL */
Newx(s, len, char);
DEBUG_L(PerlIO_printf(Perl_debug_log,
"mem_collxfrm_: highest 1-byte collating character"
" in locale %s is 0x%02X\n",
PL_collation_name,
PL_strxfrm_max_cp));

{
STRLEN i;
STRLEN d= 0;
char * e = (char *) t + len;

for (i = 0; i < len; i+= UTF8SKIP(t + i)) {
U8 cur_char = t[i];
if (UTF8_IS_INVARIANT(cur_char)) {
s[d++] = cur_char;
}
else if (UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(t + i, e)) {
s[d++] = EIGHT_BIT_UTF8_TO_NATIVE(cur_char, t[i+1]);
}
else { /* Replace illegal cp with highest collating
one */
s[d++] = PL_strxfrm_max_cp;
}
}
s[d++] = '\0';
Renew(s, d, char); /* Free up unused space */
Safefree(cur_max_x);
}

/* Here we know which legal code point collates the highest. We
* are ready to construct the non-UTF-8 string. The length will be
* at least 1 byte smaller than the input string (because we
* changed at least one 2-byte character into a single byte), but
* that is eaten up by the trailing NUL
*
* May shrink; will never grow */
Newx(sans_highs, len, char);
char * d = sans_highs;

const char * const e = s + len;
while (s < e) {
if (UTF8_IS_INVARIANT(*s)) {
*d++ = *s++;
continue;
}

if (UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(s, e)) {
*d++ = EIGHT_BIT_UTF8_TO_NATIVE(*s, *(s + 1));
}
else { /* Replace illegal cp's with highest collating one */
*d++ = PL_strxfrm_max_cp;
}

s+= UTF8SKIP(s);
}
}

/* Here, we have constructed a modified version of the input. It could
* be that we already had a modified copy before we did this version.
* If so, that copy is no longer needed */
if (t != input_string) {
Safefree(t);
len = d - sans_highs;
*d++ = '\0';

s = sans_highs;
}
}
/* else // Here both the locale and string are UTF-8 */
/* XXX convert above Unicode to 10FFFF? */

length_in_chars = (utf8)
? utf8_length((U8 *) s, (U8 *) s + len)
Expand All @@ -9988,6 +9990,13 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
/* Store the collation id */
*(PERL_UINTMAX_T *)xbuf = PL_collation_ix;

# define CLEANUP_STRXFRM_COMMON \
STMT_START { \
Safefree(free_me); \
Safefree(sans_nuls); \
Safefree(sans_highs); \
} STMT_END

# if defined(USE_POSIX_2008_LOCALE) && defined HAS_STRXFRM_L
# ifdef USE_LOCALE_CTYPE

Expand All @@ -10004,6 +10013,7 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
STMT_START { \
if (constructed_locale != (locale_t) 0) \
freelocale(constructed_locale); \
CLEANUP_STRXFRM_COMMON; \
} STMT_END
# else
# define my_strxfrm(dest, src, n) strxfrm(dest, src, n)
Expand All @@ -10012,9 +10022,12 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
orig_CTYPE_locale = toggle_locale_c(LC_CTYPE, PL_collation_name);

# define CLEANUP_STRXFRM \
restore_toggled_locale_c(LC_CTYPE, orig_CTYPE_locale)
STMT_START { \
restore_toggled_locale_c(LC_CTYPE, orig_CTYPE_locale); \
CLEANUP_STRXFRM_COMMON; \
} STMT_END
# else
# define CLEANUP_STRXFRM NOOP
# define CLEANUP_STRXFRM CLEANUP_STRXFRM_COMMON
# endif
# endif

Expand Down Expand Up @@ -10154,28 +10167,20 @@ Perl_mem_collxfrm_(pTHX_ const char *input_string,
first_time = FALSE;
}

CLEANUP_STRXFRM;

DEBUG_L(print_collxfrm_input_and_return(s, s + len, xbuf, *xlen, utf8));
CLEANUP_STRXFRM;

/* Free up unneeded space; retain enough for trailing NUL */
Renew(xbuf, COLLXFRM_HDR_LEN + *xlen + 1, char);

if (s != input_string) {
Safefree(s);
}

return xbuf;

bad:

CLEANUP_STRXFRM;
DEBUG_L(print_collxfrm_input_and_return(s, s + len, NULL, 0, utf8));
CLEANUP_STRXFRM;

Safefree(xbuf);
if (s != input_string) {
Safefree(s);
}
*xlen = 0;

return NULL;
Expand Down
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