diff options
Diffstat (limited to 'dns/dnsmasq/files/patch-137ae2e9cf0dc3596641e7c8b91d15307a35319e')
| -rw-r--r-- | dns/dnsmasq/files/patch-137ae2e9cf0dc3596641e7c8b91d15307a35319e | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/dns/dnsmasq/files/patch-137ae2e9cf0dc3596641e7c8b91d15307a35319e b/dns/dnsmasq/files/patch-137ae2e9cf0dc3596641e7c8b91d15307a35319e new file mode 100644 index 000000000000..d87d90c8238f --- /dev/null +++ b/dns/dnsmasq/files/patch-137ae2e9cf0dc3596641e7c8b91d15307a35319e @@ -0,0 +1,218 @@ +From 137ae2e9cf0dc3596641e7c8b91d15307a35319e Mon Sep 17 00:00:00 2001 +From: Taylor R Campbell <campbell+dnsmasq@mumble.net> +Date: Sat, 25 Feb 2023 15:00:30 +0000 +Subject: [PATCH] Avoid undefined behaviour with the ctype(3) functions. + +As defined in the C standard: + + In all cases the argument is an int, the value of which shall + be representable as an unsigned char or shall equal the value + of the macro EOF. If the argument has any other value, the + behavior is undefined. + +This is because they're designed to work with the int values returned +by getc or fgetc; they need extra work to handle a char value. + +If EOF is -1 (as it almost always is), with 8-bit bytes, the allowed +inputs to the ctype(3) functions are: + + {-1, 0, 1, 2, 3, ..., 255}. + +However, on platforms where char is signed, such as x86 with the +usual ABI, code like + + char *arg = ...; + ... isspace(*arg) ... + +may pass in values in the range: + + {-128, -127, -126, ..., -2, -1, 0, 1, ..., 127}. + +This has two problems: + +1. Inputs in the set {-128, -127, -126, ..., -2} are forbidden. + +2. The non-EOF byte 0xff is conflated with the value EOF = -1, so + even though the input is not forbidden, it may give the wrong + answer. + +Casting char to int first before passing the result to ctype(3) +doesn't help: inputs like -128 are unchanged by this cast. It is +necessary to cast char inputs to unsigned char first; you can then +cast to int if you like but there's no need because the functions +will always convert the argument to int by definition. So the above +fragment needs to be: + + char *arg = ...; + ... isspace((unsigned char)*arg) ... + +This patch inserts unsigned char casts where necessary, and changes +int casts to unsigned char casts where the input is char. + +I left alone int casts where the input is unsigned char already -- +they're not immediately harmful, although they would have the effect +of suppressing some compiler warnings if the input is ever changed to +be char instead of unsigned char, so it might be better to remove +those casts too. + +I also left alone calls where the input is int to begin with because +it came from getc; casting to unsigned char here would be wrong, of +course. +--- + src/dhcp-common.c | 6 +++--- + src/dhcp.c | 6 +++--- + src/loop.c | 2 +- + src/option.c | 8 ++++---- + src/rfc1035.c | 2 +- + src/rfc2131.c | 2 +- + src/tftp.c | 2 +- + 7 files changed, 14 insertions(+), 14 deletions(-) + +diff --git a/src/dhcp-common.c b/src/dhcp-common.c +index 84081ce..b4d255e 100644 +--- a/src/dhcp-common.c ++++ b/src/dhcp-common.c +@@ -838,7 +838,7 @@ char *option_string(int prot, unsigned int opt, unsigned char *val, int opt_len, + for (i = 0, j = 0; i < opt_len && j < buf_len ; i++) + { + char c = val[i]; +- if (isprint((int)c)) ++ if (isprint((unsigned char)c)) + buf[j++] = c; + } + #ifdef HAVE_DHCP6 +@@ -852,7 +852,7 @@ char *option_string(int prot, unsigned int opt, unsigned char *val, int opt_len, + for (k = i + 1; k < opt_len && k < l && j < buf_len ; k++) + { + char c = val[k]; +- if (isprint((int)c)) ++ if (isprint((unsigned char)c)) + buf[j++] = c; + } + i = l; +@@ -873,7 +873,7 @@ char *option_string(int prot, unsigned int opt, unsigned char *val, int opt_len, + for (k = 0; k < len && j < buf_len; k++) + { + char c = *p++; +- if (isprint((int)c)) ++ if (isprint((unsigned char)c)) + buf[j++] = c; + } + i += len +2; +diff --git a/src/dhcp.c b/src/dhcp.c +index 42d819f..e578391 100644 +--- a/src/dhcp.c ++++ b/src/dhcp.c +@@ -916,14 +916,14 @@ void dhcp_read_ethers(void) + + lineno++; + +- while (strlen(buff) > 0 && isspace((int)buff[strlen(buff)-1])) ++ while (strlen(buff) > 0 && isspace((unsigned char)buff[strlen(buff)-1])) + buff[strlen(buff)-1] = 0; + + if ((*buff == '#') || (*buff == '+') || (*buff == 0)) + continue; + +- for (ip = buff; *ip && !isspace((int)*ip); ip++); +- for(; *ip && isspace((int)*ip); ip++) ++ for (ip = buff; *ip && !isspace((unsigned char)*ip); ip++); ++ for(; *ip && isspace((unsigned char)*ip); ip++) + *ip = 0; + if (!*ip || parse_hex(buff, hwaddr, ETHER_ADDR_LEN, NULL, NULL) != ETHER_ADDR_LEN) + { +diff --git a/src/loop.c b/src/loop.c +index cd4855e..19bfae0 100644 +--- a/src/loop.c ++++ b/src/loop.c +@@ -92,7 +92,7 @@ int detect_loop(char *query, int type) + return 0; + + for (i = 0; i < 8; i++) +- if (!isxdigit(query[i])) ++ if (!isxdigit((unsigned char)query[i])) + return 0; + + uid = strtol(query, NULL, 16); +diff --git a/src/option.c b/src/option.c +index e4810fd..1090bca 100644 +--- a/src/option.c ++++ b/src/option.c +@@ -2751,7 +2751,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma + ret_err(gen_err); + + for (p = arg; *p; p++) +- if (!isxdigit((int)*p)) ++ if (!isxdigit((unsigned char)*p)) + ret_err(gen_err); + + set_option_bool(OPT_UMBRELLA_DEVID); +@@ -4836,7 +4836,7 @@ err: + new->target = target; + new->ttl = ttl; + +- for (arg += arglen+1; *arg && isspace(*arg); arg++); ++ for (arg += arglen+1; *arg && isspace((unsigned char)*arg); arg++); + } + + break; +@@ -5227,7 +5227,7 @@ err: + unhide_metas(keyhex); + /* 4034: "Whitespace is allowed within digits" */ + for (cp = keyhex; *cp; ) +- if (isspace(*cp)) ++ if (isspace((unsigned char)*cp)) + for (cp1 = cp; *cp1; cp1++) + *cp1 = *(cp1+1); + else +@@ -5315,7 +5315,7 @@ static void read_file(char *file, FILE *f, int hard_opt, int from_script) + memmove(p, p+1, strlen(p+1)+1); + } + +- if (isspace(*p)) ++ if (isspace((unsigned char)*p)) + { + *p = ' '; + white = 1; +diff --git a/src/rfc1035.c b/src/rfc1035.c +index 5c0df56..1693253 100644 +--- a/src/rfc1035.c ++++ b/src/rfc1035.c +@@ -519,7 +519,7 @@ static int print_txt(struct dns_header *header, const size_t qlen, char *name, + /* make counted string zero-term and sanitise */ + for (i = 0; i < len; i++) + { +- if (!isprint((int)*(p3+1))) ++ if (!isprint((unsigned char)*(p3+1))) + break; + *p3 = *(p3+1); + p3++; +diff --git a/src/rfc2131.c b/src/rfc2131.c +index 17e97b5..5190982 100644 +--- a/src/rfc2131.c ++++ b/src/rfc2131.c +@@ -1678,7 +1678,7 @@ static int sanitise(unsigned char *opt, char *buf) + for (i = option_len(opt); i > 0; i--) + { + char c = *p++; +- if (isprint((int)c)) ++ if (isprint((unsigned char)c)) + *buf++ = c; + } + *buf = 0; /* add terminator */ +diff --git a/src/tftp.c b/src/tftp.c +index 0861f37..8e1dc4a 100644 +--- a/src/tftp.c ++++ b/src/tftp.c +@@ -405,7 +405,7 @@ void tftp_request(struct listener *listen, time_t now) + if (*p == '\\') + *p = '/'; + else if (option_bool(OPT_TFTP_LC)) +- *p = tolower(*p); ++ *p = tolower((unsigned char)*p); + + strcpy(daemon->namebuff, "/"); + if (prefix) +-- +2.20.1 + |