From fff56ce43844d376365c6e057e89bded070f717c Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Wed, 2 Sep 2020 12:23:47 +0930 Subject: [PATCH] ubsan: d-demangle.c:214 signed integer overflow Running the libiberty testsuite ./test-demangle < libiberty/testsuite/d-demangle-expected libiberty/d-demangle.c:214:14: runtime error: signed integer overflow: 922337203 * 10 cannot be represented in type 'long int' On looking at silencing ubsan, I found a real bug in dlang_number. For a 32-bit long, some overflows won't be detected. For example, 21474836480. Why? Well 214748364 * 10 is 0x7FFFFFF8 (no overflow so far). Adding 8 gives 0x80000000 (which does overflow but there is no test for that overflow in the code). Then multiplying 0x80000000 * 10 = 0x500000000 = 0 won't be caught by the multiplication overflow test. The same holds for a 64-bit long using similarly crafted digit sequences. * d-demangle.c: Include limits.h. (ULONG_MAX, UINT_MAX): Provide fall-back definition. (dlang_number): Simplify and correct overflow test. Only write *ret on returning non-NULL. Make "ret" an unsigned long*. Only succeed for result of [0,UINT_MAX]. (dlang_decode_backref): Simplify and correct overflow test. Only write *ret on returning non-NULL. Only succeed for result [1,MAX_LONG]. (dlang_backref): Remove now unnecessary range check. (dlang_symbol_name_p): Likewise. (string_need): Take a size_t n arg, and use size_t tem. (string_append): Use size_t n. (string_appendn, string_prependn): Take a size_t n arg. (TEMPLATE_LENGTH_UNKNOWN): Define as -1UL. (dlang_lname, dlang_parse_template): Take an unsigned long len arg. (dlang_symbol_backref, dlang_identifier, dlang_parse_integer), (dlang_parse_integer, dlang_parse_string), (dlang_parse_arrayliteral, dlang_parse_assocarray), (dlang_parse_structlit, dlang_parse_tuple), (dlang_template_symbol_param, dlang_template_args): Use unsigned long variables. * testsuite/d-demangle-expected: Add new tests. --- libiberty/d-demangle.c | 106 ++++++++++++++---------- libiberty/testsuite/d-demangle-expected | 8 ++ 2 files changed, 69 insertions(+), 45 deletions(-) diff --git a/libiberty/d-demangle.c b/libiberty/d-demangle.c index 2e52eff7617..cd3bc96303e 100644 --- a/libiberty/d-demangle.c +++ b/libiberty/d-demangle.c @@ -31,6 +31,9 @@ If not, see . */ #ifdef HAVE_CONFIG_H #include "config.h" #endif +#ifdef HAVE_LIMITS_H +#include +#endif #include "safe-ctype.h" @@ -45,6 +48,13 @@ If not, see . */ #include #include "libiberty.h" +#ifndef ULONG_MAX +#define ULONG_MAX (~0UL) +#endif +#ifndef UINT_MAX +#define UINT_MAX (~0U) +#endif + /* A mini string-handling package */ typedef struct string /* Beware: these aren't required to be */ @@ -55,9 +65,9 @@ typedef struct string /* Beware: these aren't required to be */ } string; static void -string_need (string *s, int n) +string_need (string *s, size_t n) { - int tem; + size_t tem; if (s->b == NULL) { @@ -68,7 +78,7 @@ string_need (string *s, int n) s->p = s->b = XNEWVEC (char, n); s->e = s->b + n; } - else if (s->e - s->p < n) + else if ((size_t) (s->e - s->p) < n) { tem = s->p - s->b; n += tem; @@ -117,14 +127,14 @@ string_setlength (string *s, int n) static void string_append (string *p, const char *s) { - int n = strlen (s); + size_t n = strlen (s); string_need (p, n); memcpy (p->p, s, n); p->p += n; } static void -string_appendn (string *p, const char *s, int n) +string_appendn (string *p, const char *s, size_t n) { if (n != 0) { @@ -135,7 +145,7 @@ string_appendn (string *p, const char *s, int n) } static void -string_prependn (string *p, const char *s, int n) +string_prependn (string *p, const char *s, size_t n) { char *q; @@ -170,7 +180,7 @@ struct dlang_info }; /* Pass as the LEN to dlang_parse_template if symbol length is not known. */ -enum { TEMPLATE_LENGTH_UNKNOWN = -1 }; +#define TEMPLATE_LENGTH_UNKNOWN (-1UL) /* Prototypes for forward referenced functions */ static const char *dlang_function_type (string *, const char *, @@ -193,38 +203,39 @@ static const char *dlang_parse_tuple (string *, const char *, struct dlang_info *); static const char *dlang_parse_template (string *, const char *, - struct dlang_info *, long); + struct dlang_info *, unsigned long); -static const char *dlang_lname (string *, const char *, long); +static const char *dlang_lname (string *, const char *, unsigned long); /* Extract the number from MANGLED, and assign the result to RET. - Return the remaining string on success or NULL on failure. */ + Return the remaining string on success or NULL on failure. + A result larger than UINT_MAX is considered a failure. */ static const char * -dlang_number (const char *mangled, long *ret) +dlang_number (const char *mangled, unsigned long *ret) { /* Return NULL if trying to extract something that isn't a digit. */ if (mangled == NULL || !ISDIGIT (*mangled)) return NULL; - (*ret) = 0; + unsigned long val = 0; while (ISDIGIT (*mangled)) { - (*ret) *= 10; + unsigned long digit = mangled[0] - '0'; - /* If an overflow occured when multiplying by ten, the result - will not be a multiple of ten. */ - if ((*ret % 10) != 0) + /* Check for overflow. */ + if (val > (UINT_MAX - digit) / 10) return NULL; - (*ret) += mangled[0] - '0'; + val = val * 10 + digit; mangled++; } - if (*mangled == '\0' || *ret < 0) + if (*mangled == '\0') return NULL; + *ret = val; return mangled; } @@ -273,7 +284,8 @@ dlang_call_convention_p (const char *mangled) } /* Extract the back reference position from MANGLED, and assign the result - to RET. Return the remaining string on success or NULL on failure. */ + to RET. Return the remaining string on success or NULL on failure. + A result <= 0 is a failure. */ static const char * dlang_decode_backref (const char *mangled, long *ret) { @@ -294,24 +306,26 @@ dlang_decode_backref (const char *mangled, long *ret) [A-Z] NumberBackRef ^ */ - (*ret) = 0; + unsigned long val = 0; while (ISALPHA (*mangled)) { - (*ret) *= 26; + /* Check for overflow. */ + if (val > (ULONG_MAX - 25) / 26) + break; - /* If an overflow occured when multiplying by 26, the result - will not be a multiple of 26. */ - if ((*ret % 26) != 0) - return NULL; + val *= 26; if (mangled[0] >= 'a' && mangled[0] <= 'z') { - (*ret) += mangled[0] - 'a'; + val += mangled[0] - 'a'; + if ((long) val <= 0) + break; + *ret = val; return mangled + 1; } - (*ret) += mangled[0] - 'A'; + val += mangled[0] - 'A'; mangled++; } @@ -337,7 +351,7 @@ dlang_backref (const char *mangled, const char **ret, struct dlang_info *info) if (mangled == NULL) return NULL; - if (refpos <= 0 || refpos > qpos - info->s) + if (refpos > qpos - info->s) return NULL; /* Set the position of the back reference. */ @@ -359,7 +373,7 @@ dlang_symbol_backref (string *decl, const char *mangled, ^ */ const char *backref; - long len; + unsigned long len; /* Get position of the back reference. */ mangled = dlang_backref (mangled, &backref, info); @@ -435,7 +449,7 @@ dlang_symbol_name_p (const char *mangled, struct dlang_info *info) return 0; mangled = dlang_decode_backref (mangled + 1, &ret); - if (mangled == NULL || ret <= 0 || ret > qref - info->s) + if (mangled == NULL || ret > qref - info->s) return 0; return ISDIGIT (qref[-ret]); @@ -993,7 +1007,7 @@ dlang_type (string *decl, const char *mangled, struct dlang_info *info) static const char * dlang_identifier (string *decl, const char *mangled, struct dlang_info *info) { - long len; + unsigned long len; if (mangled == NULL || *mangled == '\0') return NULL; @@ -1011,7 +1025,7 @@ dlang_identifier (string *decl, const char *mangled, struct dlang_info *info) if (endptr == NULL || len == 0) return NULL; - if (strlen (endptr) < (size_t) len) + if (strlen (endptr) < len) return NULL; mangled = endptr; @@ -1028,7 +1042,7 @@ dlang_identifier (string *decl, const char *mangled, struct dlang_info *info) with special treatment for some magic compiler generted symbols. Return the remaining string on success or NULL on failure. */ static const char * -dlang_lname (string *decl, const char *mangled, long len) +dlang_lname (string *decl, const char *mangled, unsigned long len) { switch (len) { @@ -1127,7 +1141,7 @@ dlang_parse_integer (string *decl, const char *mangled, char type) char value[20]; int pos = sizeof(value); int width = 0; - long val; + unsigned long val; mangled = dlang_number (mangled, &val); if (mangled == NULL) @@ -1183,7 +1197,7 @@ dlang_parse_integer (string *decl, const char *mangled, char type) else if (type == 'b') { /* Parse boolean value. */ - long val; + unsigned long val; mangled = dlang_number (mangled, &val); if (mangled == NULL) @@ -1302,7 +1316,7 @@ static const char * dlang_parse_string (string *decl, const char *mangled) { char type = *mangled; - long len; + unsigned long len; mangled++; mangled = dlang_number (mangled, &len); @@ -1366,7 +1380,7 @@ dlang_parse_string (string *decl, const char *mangled) static const char * dlang_parse_arrayliteral (string *decl, const char *mangled) { - long elements; + unsigned long elements; mangled = dlang_number (mangled, &elements); if (mangled == NULL) @@ -1392,7 +1406,7 @@ dlang_parse_arrayliteral (string *decl, const char *mangled) static const char * dlang_parse_assocarray (string *decl, const char *mangled) { - long elements; + unsigned long elements; mangled = dlang_number (mangled, &elements); if (mangled == NULL) @@ -1423,7 +1437,7 @@ dlang_parse_assocarray (string *decl, const char *mangled) static const char * dlang_parse_structlit (string *decl, const char *mangled, const char *name) { - long args; + unsigned long args; mangled = dlang_number (mangled, &args); if (mangled == NULL) @@ -1650,7 +1664,7 @@ dlang_parse_qualified (string *decl, const char *mangled, static const char * dlang_parse_tuple (string *decl, const char *mangled, struct dlang_info *info) { - long elements; + unsigned long elements; mangled = dlang_number (mangled, &elements); if (mangled == NULL) @@ -1685,7 +1699,7 @@ dlang_template_symbol_param (string *decl, const char *mangled, if (*mangled == 'Q') return dlang_parse_qualified (decl, mangled, info, 0); - long len; + unsigned long len; const char *endptr = dlang_number (mangled, &len); if (endptr == NULL || len == 0) @@ -1798,12 +1812,12 @@ dlang_template_args (string *decl, const char *mangled, struct dlang_info *info) } case 'X': /* Externally mangled parameter. */ { - long len; + unsigned long len; const char *endptr; mangled++; endptr = dlang_number (mangled, &len); - if (endptr == NULL || strlen (endptr) < (size_t) len) + if (endptr == NULL || strlen (endptr) < len) return NULL; string_appendn (decl, endptr, len); @@ -1823,7 +1837,7 @@ dlang_template_args (string *decl, const char *mangled, struct dlang_info *info) Returns the remaining signature on success or NULL on failure. */ static const char * dlang_parse_template (string *decl, const char *mangled, - struct dlang_info *info, long len) + struct dlang_info *info, unsigned long len) { const char *start = mangled; string args; @@ -1859,7 +1873,9 @@ dlang_parse_template (string *decl, const char *mangled, string_delete (&args); /* Check for template name length mismatch. */ - if (len != TEMPLATE_LENGTH_UNKNOWN && mangled && (mangled - start) != len) + if (len != TEMPLATE_LENGTH_UNKNOWN + && mangled + && (unsigned long) (mangled - start) != len) return NULL; return mangled; diff --git a/libiberty/testsuite/d-demangle-expected b/libiberty/testsuite/d-demangle-expected index ffb317f23d4..ba0ffed5c8d 100644 --- a/libiberty/testsuite/d-demangle-expected +++ b/libiberty/testsuite/d-demangle-expected @@ -1140,6 +1140,14 @@ _D4test34__T3barVG3uw3_616263VG3wd3_646566Z1xi test.bar!("abc"w, "def"d).x # --format=dlang +_D4test21__T3funVwi4294967295Z3funFNaNbNiNfZv +test.fun!('\Uffffffff').fun() +# +--format=dlang +_D4test21__T3funVwi4294967296Z3funFNaNbNiNfZv +_D4test21__T3funVwi4294967296Z3funFNaNbNiNfZv +# +--format=dlang _D6plugin8generateFiiZAya plugin.generate(int, int) # -- 2.30.2