diff options
Diffstat (limited to 'src/common/util.c')
| -rw-r--r-- | src/common/util.c | 431 |
1 files changed, 350 insertions, 81 deletions
diff --git a/src/common/util.c b/src/common/util.c index 04cc6b12c6..442d57a2cf 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -1,6 +1,6 @@ /* Copyright (c) 2003, Roger Dingledine * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2013, The Tor Project, Inc. */ + * Copyright (c) 2007-2015, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -96,6 +96,10 @@ #include <sys/wait.h> #endif +#ifdef __clang_analyzer__ +#undef MALLOC_ZERO_WORKS +#endif + /* ===== * Assertion helper. * ===== */ @@ -191,33 +195,40 @@ tor_malloc_zero_(size_t size DMALLOC_PARAMS) return result; } +/* The square root of SIZE_MAX + 1. If a is less than this, and b is less + * than this, then a*b is less than SIZE_MAX. (For example, if size_t is + * 32 bits, then SIZE_MAX is 0xffffffff and this value is 0x10000. If a and + * b are less than this, then their product is at most (65535*65535) == + * 0xfffe0001. */ +#define SQRT_SIZE_MAX_P1 (((size_t)1) << (sizeof(size_t)*4)) + +/** Return non-zero if and only if the product of the arguments is exact. */ +static INLINE int +size_mul_check(const size_t x, const size_t y) +{ + /* This first check is equivalent to + (x < SQRT_SIZE_MAX_P1 && y < SQRT_SIZE_MAX_P1) + + Rationale: if either one of x or y is >= SQRT_SIZE_MAX_P1, then it + will have some bit set in its most significant half. + */ + return ((x|y) < SQRT_SIZE_MAX_P1 || + y == 0 || + x <= SIZE_MAX / y); +} + /** Allocate a chunk of <b>nmemb</b>*<b>size</b> bytes of memory, fill * the memory with zero bytes, and return a pointer to the result. * Log and terminate the process on error. (Same as * calloc(<b>nmemb</b>,<b>size</b>), but never returns NULL.) - * - * XXXX This implementation probably asserts in cases where it could - * work, because it only tries dividing SIZE_MAX by size (according to - * the calloc(3) man page, the size of an element of the nmemb-element - * array to be allocated), not by nmemb (which could in theory be - * smaller than size). Don't do that then. + * The second argument (<b>size</b>) should preferably be non-zero + * and a compile-time constant. */ void * tor_calloc_(size_t nmemb, size_t size DMALLOC_PARAMS) { - /* You may ask yourself, "wouldn't it be smart to use calloc instead of - * malloc+memset? Perhaps libc's calloc knows some nifty optimization trick - * we don't!" Indeed it does, but its optimizations are only a big win when - * we're allocating something very big (it knows if it just got the memory - * from the OS in a pre-zeroed state). We don't want to use tor_malloc_zero - * for big stuff, so we don't bother with calloc. */ - void *result; - size_t max_nmemb = (size == 0) ? SIZE_MAX : SIZE_MAX/size; - - tor_assert(nmemb < max_nmemb); - - result = tor_malloc_zero_((nmemb * size) DMALLOC_FN_ARGS); - return result; + tor_assert(size_mul_check(nmemb, size)); + return tor_malloc_zero_((nmemb * size) DMALLOC_FN_ARGS); } /** Change the size of the memory block pointed to by <b>ptr</b> to <b>size</b> @@ -231,6 +242,13 @@ tor_realloc_(void *ptr, size_t size DMALLOC_PARAMS) tor_assert(size < SIZE_T_CEILING); +#ifndef MALLOC_ZERO_WORKS + /* Some libc mallocs don't work when size==0. Override them. */ + if (size==0) { + size=1; + } +#endif + #ifdef USE_DMALLOC result = dmalloc_realloc(file, line, ptr, size, DMALLOC_FUNC_REALLOC, 0); #else @@ -244,6 +262,20 @@ tor_realloc_(void *ptr, size_t size DMALLOC_PARAMS) return result; } +/** + * Try to realloc <b>ptr</b> so that it takes up sz1 * sz2 bytes. Check for + * overflow. Unlike other allocation functions, return NULL on overflow. + */ +void * +tor_reallocarray_(void *ptr, size_t sz1, size_t sz2 DMALLOC_PARAMS) +{ + /* XXXX we can make this return 0, but we would need to check all the + * reallocarray users. */ + tor_assert(size_mul_check(sz1, sz2)); + + return tor_realloc(ptr, (sz1 * sz2) DMALLOC_FN_ARGS); +} + /** Return a newly allocated copy of the NUL-terminated string s. On * error, log and terminate. (Like strdup(s), but never returns * NULL.) @@ -481,6 +513,61 @@ round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor) return number; } +/** Return the lowest x in [INT64_MIN, INT64_MAX] such that x is at least + * <b>number</b>, and x modulo <b>divisor</b> == 0. */ +int64_t +round_int64_to_next_multiple_of(int64_t number, int64_t divisor) +{ + tor_assert(divisor > 0); + if (number >= 0 && INT64_MAX - divisor + 1 >= number) + number += divisor - 1; + number -= number % divisor; + return number; +} + +/** Transform a random value <b>p</b> from the uniform distribution in + * [0.0, 1.0[ into a Laplace distributed value with location parameter + * <b>mu</b> and scale parameter <b>b</b>. Truncate the final result + * to be an integer in [INT64_MIN, INT64_MAX]. */ +int64_t +sample_laplace_distribution(double mu, double b, double p) +{ + double result; + + tor_assert(p >= 0.0 && p < 1.0); + /* This is the "inverse cumulative distribution function" from: + * http://en.wikipedia.org/wiki/Laplace_distribution */ + result = mu - b * (p > 0.5 ? 1.0 : -1.0) + * tor_mathlog(1.0 - 2.0 * fabs(p - 0.5)); + + if (result >= INT64_MAX) + return INT64_MAX; + else if (result <= INT64_MIN) + return INT64_MIN; + else + return (int64_t) result; +} + +/** Add random noise between INT64_MIN and INT64_MAX coming from a + * Laplace distribution with mu = 0 and b = <b>delta_f</b>/<b>epsilon</b> + * to <b>signal</b> based on the provided <b>random</b> value in + * [0.0, 1.0[. */ +int64_t +add_laplace_noise(int64_t signal, double random, double delta_f, + double epsilon) +{ + int64_t noise = sample_laplace_distribution( + 0.0, /* just add noise, no further signal */ + delta_f / epsilon, random); + + if (noise > 0 && INT64_MAX - noise < signal) + return INT64_MAX; + else if (noise < 0 && INT64_MIN - noise > signal) + return INT64_MIN; + else + return signal + noise; +} + /** Return the number of bits set in <b>v</b>. */ int n_bits_set_u8(uint8_t v) @@ -932,6 +1019,68 @@ string_is_key_value(int severity, const char *string) return 1; } +/** Return true if <b>string</b> represents a valid IPv4 adddress in + * 'a.b.c.d' form. + */ +int +string_is_valid_ipv4_address(const char *string) +{ + struct in_addr addr; + + return (tor_inet_pton(AF_INET,string,&addr) == 1); +} + +/** Return true if <b>string</b> represents a valid IPv6 address in + * a form that inet_pton() can parse. + */ +int +string_is_valid_ipv6_address(const char *string) +{ + struct in6_addr addr; + + return (tor_inet_pton(AF_INET6,string,&addr) == 1); +} + +/** Return true iff <b>string</b> matches a pattern of DNS names + * that we allow Tor clients to connect to. + */ +int +string_is_valid_hostname(const char *string) +{ + int result = 1; + smartlist_t *components; + + components = smartlist_new(); + + smartlist_split_string(components,string,".",0,0); + + SMARTLIST_FOREACH_BEGIN(components, char *, c) { + if (c[0] == '-') { + result = 0; + break; + } + + do { + if ((*c >= 'a' && *c <= 'z') || + (*c >= 'A' && *c <= 'Z') || + (*c >= '0' && *c <= '9') || + (*c == '-')) + c++; + else + result = 0; + } while (result && *c); + + } SMARTLIST_FOREACH_END(c); + + SMARTLIST_FOREACH_BEGIN(components, char *, c) { + tor_free(c); + } SMARTLIST_FOREACH_END(c); + + smartlist_free(components); + + return result; +} + /** Return true iff the DIGEST256_LEN bytes in digest are all zero. */ int tor_digest256_is_zero(const char *digest) @@ -1186,9 +1335,14 @@ esc_for_log(const char *s) } } + tor_assert(len <= SSIZE_MAX); + result = outp = tor_malloc(len); *outp++ = '\"'; for (cp = s; *cp; ++cp) { + /* This assertion should always succeed, since we will write at least + * one char here, and two chars for closing quote and nul later */ + tor_assert((outp-result) < (ssize_t)len-2); switch (*cp) { case '\\': case '\"': @@ -1212,6 +1366,7 @@ esc_for_log(const char *s) if (TOR_ISPRINT(*cp) && ((uint8_t)*cp)<127) { *outp++ = *cp; } else { + tor_assert((outp-result) < (ssize_t)len-4); tor_snprintf(outp, 5, "\\%03o", (int)(uint8_t) *cp); outp += 4; } @@ -1219,12 +1374,27 @@ esc_for_log(const char *s) } } + tor_assert((outp-result) <= (ssize_t)len-2); *outp++ = '\"'; *outp++ = 0; return result; } +/** Similar to esc_for_log. Allocate and return a new string representing + * the first n characters in <b>chars</b>, surround by quotes and using + * standard C escapes. If a NUL character is encountered in <b>chars</b>, + * the resulting string will be terminated there. + */ +char * +esc_for_log_len(const char *chars, size_t n) +{ + char *string = tor_strndup(chars, n); + char *string_escaped = esc_for_log(string); + tor_free(string); + return string_escaped; +} + /** Allocate and return a new string representing the contents of <b>s</b>, * surrounded by quotes and using standard C escapes. * @@ -1347,7 +1517,8 @@ n_leapdays(int y1, int y2) --y2; return (y2/4 - y1/4) - (y2/100 - y1/100) + (y2/400 - y1/400); } -/** Number of days per month in non-leap year; used by tor_timegm. */ +/** Number of days per month in non-leap year; used by tor_timegm and + * parse_rfc1123_time. */ static const int days_per_month[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; @@ -1361,10 +1532,32 @@ tor_timegm(const struct tm *tm, time_t *time_out) * It's way more brute-force than fiddling with tzset(). */ time_t year, days, hours, minutes, seconds; - int i; - year = tm->tm_year + 1900; - if (year < 1970 || tm->tm_mon < 0 || tm->tm_mon > 11 || - tm->tm_year >= INT32_MAX-1900) { + int i, invalid_year, dpm; + /* avoid int overflow on addition */ + if (tm->tm_year < INT32_MAX-1900) { + year = tm->tm_year + 1900; + } else { + /* clamp year */ + year = INT32_MAX; + } + invalid_year = (year < 1970 || tm->tm_year >= INT32_MAX-1900); + + if (tm->tm_mon >= 0 && tm->tm_mon <= 11) { + dpm = days_per_month[tm->tm_mon]; + if (tm->tm_mon == 1 && !invalid_year && IS_LEAPYEAR(tm->tm_year)) { + dpm = 29; + } + } else { + /* invalid month - default to 0 days per month */ + dpm = 0; + } + + if (invalid_year || + tm->tm_mon < 0 || tm->tm_mon > 11 || + tm->tm_mday < 1 || tm->tm_mday > dpm || + tm->tm_hour < 0 || tm->tm_hour > 23 || + tm->tm_min < 0 || tm->tm_min > 59 || + tm->tm_sec < 0 || tm->tm_sec > 60) { log_warn(LD_BUG, "Out-of-range argument to tor_timegm"); return -1; } @@ -1428,8 +1621,9 @@ parse_rfc1123_time(const char *buf, time_t *t) struct tm tm; char month[4]; char weekday[4]; - int i, m; + int i, m, invalid_year; unsigned tm_mday, tm_year, tm_hour, tm_min, tm_sec; + unsigned dpm; if (strlen(buf) != RFC1123_TIME_LEN) return -1; @@ -1442,18 +1636,6 @@ parse_rfc1123_time(const char *buf, time_t *t) tor_free(esc); return -1; } - if (tm_mday < 1 || tm_mday > 31 || tm_hour > 23 || tm_min > 59 || - tm_sec > 60 || tm_year >= INT32_MAX || tm_year < 1970) { - char *esc = esc_for_log(buf); - log_warn(LD_GENERAL, "Got invalid RFC1123 time %s", esc); - tor_free(esc); - return -1; - } - tm.tm_mday = (int)tm_mday; - tm.tm_year = (int)tm_year; - tm.tm_hour = (int)tm_hour; - tm.tm_min = (int)tm_min; - tm.tm_sec = (int)tm_sec; m = -1; for (i = 0; i < 12; ++i) { @@ -1470,6 +1652,26 @@ parse_rfc1123_time(const char *buf, time_t *t) } tm.tm_mon = m; + invalid_year = (tm_year >= INT32_MAX || tm_year < 1970); + tor_assert(m >= 0 && m <= 11); + dpm = days_per_month[m]; + if (m == 1 && !invalid_year && IS_LEAPYEAR(tm_year)) { + dpm = 29; + } + + if (invalid_year || tm_mday < 1 || tm_mday > dpm || + tm_hour > 23 || tm_min > 59 || tm_sec > 60) { + char *esc = esc_for_log(buf); + log_warn(LD_GENERAL, "Got invalid RFC1123 time %s", esc); + tor_free(esc); + return -1; + } + tm.tm_mday = (int)tm_mday; + tm.tm_year = (int)tm_year; + tm.tm_hour = (int)tm_hour; + tm.tm_min = (int)tm_min; + tm.tm_sec = (int)tm_sec; + if (tm.tm_year < 1970) { char *esc = esc_for_log(buf); log_warn(LD_GENERAL, @@ -1526,15 +1728,18 @@ format_iso_time_nospace_usec(char *buf, const struct timeval *tv) /** Given an ISO-formatted UTC time value (after the epoch) in <b>cp</b>, * parse it and store its value in *<b>t</b>. Return 0 on success, -1 on - * failure. Ignore extraneous stuff in <b>cp</b> separated by whitespace from - * the end of the time string. */ + * failure. Ignore extraneous stuff in <b>cp</b> after the end of the time + * string, unless <b>strict</b> is set. */ int -parse_iso_time(const char *cp, time_t *t) +parse_iso_time_(const char *cp, time_t *t, int strict) { struct tm st_tm; unsigned int year=0, month=0, day=0, hour=0, minute=0, second=0; - if (tor_sscanf(cp, "%u-%2u-%2u %2u:%2u:%2u", &year, &month, - &day, &hour, &minute, &second) < 6) { + int n_fields; + char extra_char; + n_fields = tor_sscanf(cp, "%u-%2u-%2u %2u:%2u:%2u%c", &year, &month, + &day, &hour, &minute, &second, &extra_char); + if (strict ? (n_fields != 6) : (n_fields < 6)) { char *esc = esc_for_log(cp); log_warn(LD_GENERAL, "ISO time %s was unparseable", esc); tor_free(esc); @@ -1563,6 +1768,16 @@ parse_iso_time(const char *cp, time_t *t) return tor_timegm(&st_tm, t); } +/** Given an ISO-formatted UTC time value (after the epoch) in <b>cp</b>, + * parse it and store its value in *<b>t</b>. Return 0 on success, -1 on + * failure. Reject the string if any characters are present after the time. + */ +int +parse_iso_time(const char *cp, time_t *t) +{ + return parse_iso_time_(cp, t, 1); +} + /** Given a <b>date</b> in one of the three formats allowed by HTTP (ugh), * parse it into <b>tm</b>. Return 0 on success, negative on failure. */ int @@ -1641,7 +1856,11 @@ format_time_interval(char *out, size_t out_len, long interval) { /* We only report seconds if there's no hours. */ long sec = 0, min = 0, hour = 0, day = 0; - if (interval < 0) + + /* -LONG_MIN is LONG_MAX + 1, which causes signed overflow */ + if (interval < -LONG_MAX) + interval = LONG_MAX; + else if (interval < 0) interval = -interval; if (interval >= 86400) { @@ -1757,7 +1976,7 @@ write_all(tor_socket_t fd, const char *buf, size_t count, int isSocket) { size_t written = 0; ssize_t result; - tor_assert(count < SSIZE_T_MAX); + tor_assert(count < SSIZE_MAX); while (written != count) { if (isSocket) @@ -1782,7 +2001,7 @@ read_all(tor_socket_t fd, char *buf, size_t count, int isSocket) size_t numread = 0; ssize_t result; - if (count > SIZE_T_CEILING || count > SSIZE_T_MAX) + if (count > SIZE_T_CEILING || count > SSIZE_MAX) return -1; while (numread != count) { @@ -1823,15 +2042,24 @@ clean_name_for_stat(char *name) #endif } -/** Return FN_ERROR if filename can't be read, FN_NOENT if it doesn't - * exist, FN_FILE if it is a regular file, or FN_DIR if it's a - * directory. On FN_ERROR, sets errno. */ +/** Return: + * FN_ERROR if filename can't be read, is NULL, or is zero-length, + * FN_NOENT if it doesn't exist, + * FN_FILE if it is a non-empty regular file, or a FIFO on unix-like systems, + * FN_EMPTY for zero-byte regular files, + * FN_DIR if it's a directory, and + * FN_ERROR for any other file type. + * On FN_ERROR and FN_NOENT, sets errno. (errno is not set when FN_ERROR + * is returned due to an unhandled file type.) */ file_status_t file_status(const char *fname) { struct stat st; char *f; int r; + if (!fname || strlen(fname) == 0) { + return FN_ERROR; + } f = tor_strdup(fname); clean_name_for_stat(f); log_debug(LD_FS, "stat()ing %s", f); @@ -1843,16 +2071,23 @@ file_status(const char *fname) } return FN_ERROR; } - if (st.st_mode & S_IFDIR) + if (st.st_mode & S_IFDIR) { return FN_DIR; - else if (st.st_mode & S_IFREG) - return FN_FILE; + } else if (st.st_mode & S_IFREG) { + if (st.st_size > 0) { + return FN_FILE; + } else if (st.st_size == 0) { + return FN_EMPTY; + } else { + return FN_ERROR; + } #ifndef _WIN32 - else if (st.st_mode & S_IFIFO) + } else if (st.st_mode & S_IFIFO) { return FN_FILE; #endif - else + } else { return FN_ERROR; + } } /** Check whether <b>dirname</b> exists and is private. If yes return 0. If @@ -1861,8 +2096,12 @@ file_status(const char *fname) * <b>check</b>&CPD_CHECK, and we think we can create it, return 0. Else * return -1. If CPD_GROUP_OK is set, then it's okay if the directory * is group-readable, but in all cases we create the directory mode 0700. - * If CPD_CHECK_MODE_ONLY is set, then we don't alter the directory permissions - * if they are too permissive: we just return -1. + * If CPD_GROUP_READ is set, existing directory behaves as CPD_GROUP_OK and + * if the directory is created it will use mode 0750 with group read + * permission. Group read privileges also assume execute permission + * as norm for directories. If CPD_CHECK_MODE_ONLY is set, then we don't + * alter the directory permissions if they are too permissive: + * we just return -1. * When effective_user is not NULL, check permissions against the given user * and its primary group. */ @@ -1874,7 +2113,7 @@ check_private_dir(const char *dirname, cpd_check_t check, struct stat st; char *f; #ifndef _WIN32 - int mask; + unsigned unwanted_bits = 0; const struct passwd *pw = NULL; uid_t running_uid; gid_t running_gid; @@ -1896,10 +2135,14 @@ check_private_dir(const char *dirname, cpd_check_t check, } if (check & CPD_CREATE) { log_info(LD_GENERAL, "Creating directory %s", dirname); -#if defined (_WIN32) && !defined (WINCE) +#if defined (_WIN32) r = mkdir(dirname); #else - r = mkdir(dirname, 0700); + if (check & CPD_GROUP_READ) { + r = mkdir(dirname, 0750); + } else { + r = mkdir(dirname, 0700); + } #endif if (r) { log_warn(LD_FS, "Error creating directory %s: %s", dirname, @@ -1952,7 +2195,8 @@ check_private_dir(const char *dirname, cpd_check_t check, tor_free(process_ownername); return -1; } - if ((check & CPD_GROUP_OK) && st.st_gid != running_gid) { + if ( (check & (CPD_GROUP_OK|CPD_GROUP_READ)) + && (st.st_gid != running_gid) ) { struct group *gr; char *process_groupname = NULL; gr = getgrgid(running_gid); @@ -1967,12 +2211,12 @@ check_private_dir(const char *dirname, cpd_check_t check, tor_free(process_groupname); return -1; } - if (check & CPD_GROUP_OK) { - mask = 0027; + if (check & (CPD_GROUP_OK|CPD_GROUP_READ)) { + unwanted_bits = 0027; } else { - mask = 0077; + unwanted_bits = 0077; } - if (st.st_mode & mask) { + if ((st.st_mode & unwanted_bits) != 0) { unsigned new_mode; if (check & CPD_CHECK_MODE_ONLY) { log_warn(LD_FS, "Permissions on directory %s are too permissive.", @@ -1982,10 +2226,13 @@ check_private_dir(const char *dirname, cpd_check_t check, log_warn(LD_FS, "Fixing permissions on directory %s", dirname); new_mode = st.st_mode; new_mode |= 0700; /* Owner should have rwx */ - new_mode &= ~mask; /* Clear the other bits that we didn't want set...*/ + if (check & CPD_GROUP_READ) { + new_mode |= 0050; /* Group should have rx */ + } + new_mode &= ~unwanted_bits; /* Clear the bits that we didn't want set...*/ if (chmod(dirname, new_mode)) { log_warn(LD_FS, "Could not chmod directory %s: %s", dirname, - strerror(errno)); + strerror(errno)); return -1; } else { return 0; @@ -2335,6 +2582,7 @@ read_file_to_str_until_eof(int fd, size_t max_bytes_to_read, size_t *sz_out) pos += r; } while (r > 0 && pos < max_bytes_to_read); + tor_assert(pos < string_max); *sz_out = pos; string[pos] = '\0'; return string; @@ -2758,7 +3006,7 @@ expand_filename(const char *filename) tor_free(username); rest = slash ? (slash+1) : ""; #else - log_warn(LD_CONFIG, "Couldn't expend homedir on system without pwd.h"); + log_warn(LD_CONFIG, "Couldn't expand homedir on system without pwd.h"); return tor_strdup(filename); #endif } @@ -2807,10 +3055,14 @@ scan_unsigned(const char **bufp, unsigned long *out, int width, int base) while (**bufp && (hex?TOR_ISXDIGIT(**bufp):TOR_ISDIGIT(**bufp)) && scanned_so_far < width) { int digit = hex?hex_decode_digit(*(*bufp)++):digit_to_num(*(*bufp)++); - unsigned long new_result = result * base + digit; - if (new_result < result) - return -1; /* over/underflow. */ - result = new_result; + // Check for overflow beforehand, without actually causing any overflow + // This preserves functionality on compilers that don't wrap overflow + // (i.e. that trap or optimise away overflow) + // result * base + digit > ULONG_MAX + // result * base > ULONG_MAX - digit + if (result > (ULONG_MAX - digit)/base) + return -1; /* Processing this digit would overflow */ + result = result * base + digit; ++scanned_so_far; } @@ -2845,10 +3097,17 @@ scan_signed(const char **bufp, long *out, int width) if (scan_unsigned(bufp, &result, width, 10) < 0) return -1; - if (neg) { + if (neg && result > 0) { if (result > ((unsigned long)LONG_MAX) + 1) return -1; /* Underflow */ - *out = -(long)result; + // Avoid overflow on the cast to signed long when result is LONG_MIN + // by subtracting 1 from the unsigned long positive value, + // then, after it has been cast to signed and negated, + // subtracting the original 1 (the double-subtraction is intentional). + // Otherwise, the cast to signed could cause a temporary long + // to equal LONG_MAX + 1, which is undefined. + // We avoid underflow on the subtraction by treating -0 as positive. + *out = (-(long)(result - 1)) - 1; } else { if (result > LONG_MAX) return -1; /* Overflow */ @@ -3381,8 +3640,9 @@ format_win_cmdline_argument(const char *arg) smartlist_add(arg_chars, (void*)&backslash); /* Allocate space for argument, quotes (if needed), and terminator */ - formatted_arg = tor_malloc(sizeof(char) * - (smartlist_len(arg_chars) + (need_quotes?2:0) + 1)); + const size_t formatted_arg_len = smartlist_len(arg_chars) + + (need_quotes ? 2 : 0) + 1; + formatted_arg = tor_malloc_zero(formatted_arg_len); /* Add leading quote */ i=0; @@ -3547,7 +3807,13 @@ format_helper_exit_status(unsigned char child_state, int saved_errno, /* Convert errno to be unsigned for hex conversion */ if (saved_errno < 0) { - unsigned_errno = (unsigned int) -saved_errno; + // Avoid overflow on the cast to unsigned int when result is INT_MIN + // by adding 1 to the signed int negative value, + // then, after it has been negated and cast to unsigned, + // adding the original 1 back (the double-addition is intentional). + // Otherwise, the cast to signed could cause a temporary int + // to equal INT_MAX + 1, which is undefined. + unsigned_errno = ((unsigned int) -(saved_errno + 1)) + 1; } else { unsigned_errno = (unsigned int) saved_errno; } @@ -4041,8 +4307,11 @@ tor_spawn_background(const char *const filename, const char **argv, status = process_handle->status = PROCESS_STATUS_RUNNING; /* Set stdout/stderr pipes to be non-blocking */ - fcntl(process_handle->stdout_pipe, F_SETFL, O_NONBLOCK); - fcntl(process_handle->stderr_pipe, F_SETFL, O_NONBLOCK); + if (fcntl(process_handle->stdout_pipe, F_SETFL, O_NONBLOCK) < 0 || + fcntl(process_handle->stderr_pipe, F_SETFL, O_NONBLOCK) < 0) { + log_warn(LD_GENERAL, "Failed to set stderror/stdout pipes nonblocking " + "in parent process: %s", strerror(errno)); + } /* Open the buffered IO streams */ process_handle->stdout_handle = fdopen(process_handle->stdout_pipe, "r"); process_handle->stderr_handle = fdopen(process_handle->stderr_pipe, "r"); @@ -4376,7 +4645,7 @@ tor_read_all_handle(HANDLE h, char *buf, size_t count, DWORD byte_count; BOOL process_exited = FALSE; - if (count > SIZE_T_CEILING || count > SSIZE_T_MAX) + if (count > SIZE_T_CEILING || count > SSIZE_MAX) return -1; while (numread != count) { @@ -4442,7 +4711,7 @@ tor_read_all_handle(FILE *h, char *buf, size_t count, if (eof) *eof = 0; - if (count > SIZE_T_CEILING || count > SSIZE_T_MAX) + if (count > SIZE_T_CEILING || count > SSIZE_MAX) return -1; while (numread != count) { @@ -5011,7 +5280,7 @@ tor_check_port_forwarding(const char *filename, for each smartlist element (one for "-p" and one for the ports), and one for the final NULL. */ args_n = 1 + 2*smartlist_len(ports_to_forward) + 1; - argv = tor_malloc_zero(sizeof(char*)*args_n); + argv = tor_calloc(args_n, sizeof(char *)); argv[argv_index++] = filename; SMARTLIST_FOREACH_BEGIN(ports_to_forward, const char *, port) { |