Prevent potential overruns of fixed-size buffers.

tglsfdc · tglsfdc · commit 69d2bc14ada1 · 2014-02-17T11:20:38.000-05:00
Coverity identified a number of places in which it couldn't prove that a string being copied into a fixed-size buffer would fit. We believe that most, perhaps all of these are in fact safe, or are copying data that is coming from a trusted source so that any overrun is not really a security issue. Nonetheless it seems prudent to forestall any risk by using strlcpy() and similar functions. Fixes by Peter Eisentraut and Jozef Mlich based on Coverity reports. In addition, fix a potential null-pointer-dereference crash in contrib/chkpass. The crypt(3) function is defined to return NULL on failure, but chkpass.c didn't check for that before using the result. The main practical case in which this could be an issue is if libc is configured to refuse to execute unapproved hashing algorithms (e.g., "FIPS mode"). This ideally should've been a separate commit, but since it touches code adjacent to one of the buffer overrun changes, I included it in this commit to avoid last-minute merge issues. This issue was reported by Honza Horak. Security: CVE-2014-0065 for buffer overruns, CVE-2014-0066 for crypt()
diff --git a/contrib/chkpass/chkpass.c b/contrib/chkpass/chkpass.c
@@ -70,6 +70,7 @@ chkpass_in(PG_FUNCTION_ARGS)
 	char	   *str = PG_GETARG_CSTRING(0);
 	chkpass    *result;
 	char		mysalt[4];
+	char	   *crypt_output;
 	static char salt_chars[] =
 	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
@@ -92,7 +93,15 @@ chkpass_in(PG_FUNCTION_ARGS)
 	mysalt[1] = salt_chars[random() & 0x3f];
 	mysalt[2] = 0;				/* technically the terminator is not necessary
 								 * but I like to play safe */
-	strcpy(result->password, crypt(str, mysalt));
+
+	crypt_output = crypt(str, mysalt);
+	if (crypt_output == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("crypt() failed")));
+
+	strlcpy(result->password, crypt_output, sizeof(result->password));
+
 	PG_RETURN_POINTER(result);
 }
 
@@ -141,9 +150,16 @@ chkpass_eq(PG_FUNCTION_ARGS)
 	chkpass    *a1 = (chkpass *) PG_GETARG_POINTER(0);
 	text	   *a2 = PG_GETARG_TEXT_PP(1);
 	char		str[9];
+	char	   *crypt_output;
 
 	text_to_cstring_buffer(a2, str, sizeof(str));
-	PG_RETURN_BOOL(strcmp(a1->password, crypt(str, a1->password)) == 0);
+	crypt_output = crypt(str, a1->password);
+	if (crypt_output == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("crypt() failed")));
+
+	PG_RETURN_BOOL(strcmp(a1->password, crypt_output) == 0);
 }
 
 PG_FUNCTION_INFO_V1(chkpass_ne);
@@ -153,7 +169,14 @@ chkpass_ne(PG_FUNCTION_ARGS)
 	chkpass    *a1 = (chkpass *) PG_GETARG_POINTER(0);
 	text	   *a2 = PG_GETARG_TEXT_PP(1);
 	char		str[9];
+	char	   *crypt_output;
 
 	text_to_cstring_buffer(a2, str, sizeof(str));
-	PG_RETURN_BOOL(strcmp(a1->password, crypt(str, a1->password)) != 0);
+	crypt_output = crypt(str, a1->password);
+	if (crypt_output == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("crypt() failed")));
+
+	PG_RETURN_BOOL(strcmp(a1->password, crypt_output) != 0);
 }
diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c
@@ -337,7 +337,7 @@ SetWALFileNameForCleanup(void)
 		if (strcmp(restartWALFileName, nextWALFileName) > 0)
 			return false;
 
-		strcpy(exclusiveCleanupFileName, restartWALFileName);
+		strlcpy(exclusiveCleanupFileName, restartWALFileName, sizeof(exclusiveCleanupFileName));
 		return true;
 	}
 
diff --git a/src/backend/tsearch/spell.c b/src/backend/tsearch/spell.c
@@ -181,7 +181,7 @@ NIAddSpell(IspellDict *Conf, const char *word, const char *flag)
 	}
 	Conf->Spell[Conf->nspell] = (SPELL *) tmpalloc(SPELLHDRSZ + strlen(word) + 1);
 	strcpy(Conf->Spell[Conf->nspell]->word, word);
-	strncpy(Conf->Spell[Conf->nspell]->p.flag, flag, MAXFLAGLEN);
+	strlcpy(Conf->Spell[Conf->nspell]->p.flag, flag, MAXFLAGLEN);
 	Conf->nspell++;
 }
 
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
@@ -89,10 +89,10 @@ char	   *days[] = {"Sunday", "Monday", "Tuesday", "Wednesday",
  * Note that this table must be strictly alphabetically ordered to allow an
  * O(ln(N)) search algorithm to be used.
  *
- * The text field is NOT guaranteed to be NULL-terminated.
+ * The token field is NOT guaranteed to be NULL-terminated.
  *
- * To keep this table reasonably small, we divide the lexval for TZ and DTZ
- * entries by 15 (so they are on 15 minute boundaries) and truncate the text
+ * To keep this table reasonably small, we divide the value for TZ and DTZ
+ * entries by 15 (so they are on 15 minute boundaries) and truncate the token
  * field at TOKMAXLEN characters.
  * Formerly, we divided by 10 rather than 15 but there are a few time zones
  * which are 30 or 45 minutes away from an even hour, most are on an hour
@@ -107,7 +107,7 @@ static datetkn *timezonetktbl = NULL;
 static int	sztimezonetktbl = 0;
 
 static const datetkn datetktbl[] = {
-/*	text, token, lexval */
+	/* token, type, value */
 	{EARLY, RESERV, DTK_EARLY}, /* "-infinity" reserved for "early time" */
 	{DA_D, ADBC, AD},			/* "ad" for years > 0 */
 	{"allballs", RESERV, DTK_ZULU},		/* 00:00:00 */
@@ -187,7 +187,7 @@ static const datetkn datetktbl[] = {
 static int	szdatetktbl = sizeof datetktbl / sizeof datetktbl[0];
 
 static datetkn deltatktbl[] = {
-	/* text, token, lexval */
+	/* token, type, value */
 	{"@", IGNORE_DTF, 0},		/* postgres relative prefix */
 	{DAGO, AGO, 0},				/* "ago" indicates negative time offset */
 	{"c", UNITS, DTK_CENTURY},	/* "century" relative */
@@ -4145,6 +4145,7 @@ InstallTimeZoneAbbrevs(tzEntry *abbrevs, int n)
 											n * sizeof(datetkn));
 	for (i = 0; i < n; i++)
 	{
+		/* do NOT use strlcpy here; token field need not be null-terminated */
 		strncpy(newtbl[i].token, abbrevs[i].abbrev, TOKMAXLEN);
 		newtbl[i].type = abbrevs[i].is_dst ? DTZ : TZ;
 		TOVAL(&newtbl[i], abbrevs[i].offset / 60);
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
@@ -3174,7 +3174,7 @@ main(int argc, char *argv[])
 		fprintf(stderr, "%s", authwarning);
 
 	/* Get directory specification used to start this executable */
-	strcpy(bin_dir, argv[0]);
+	strlcpy(bin_dir, argv[0], sizeof(bin_dir));
 	get_parent_directory(bin_dir);
 
 	printf(_("\nSuccess. You can now start the database server using:\n\n"
diff --git a/src/interfaces/ecpg/preproc/pgc.l b/src/interfaces/ecpg/preproc/pgc.l
@@ -1270,7 +1270,7 @@ parse_include(void)
 		yytext[i] = '\0';
 		memmove(yytext, yytext+1, strlen(yytext));
 	
-		strncpy(inc_file, yytext, sizeof(inc_file));
+		strlcpy(inc_file, yytext, sizeof(inc_file));
 		yyin = fopen(inc_file, "r");
 		if (!yyin)
 		{
diff --git a/src/interfaces/libpq/fe-protocol2.c b/src/interfaces/libpq/fe-protocol2.c
@@ -440,7 +440,7 @@ pqParseInput2(PGconn *conn)
 						if (!conn->result)
 							return;
 					}
-					strncpy(conn->result->cmdStatus, conn->workBuffer.data,
+					strlcpy(conn->result->cmdStatus, conn->workBuffer.data,
 							CMDSTATUS_LEN);
 					checkXactStatus(conn, conn->workBuffer.data);
 					conn->asyncStatus = PGASYNC_READY;
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
@@ -206,7 +206,7 @@ pqParseInput3(PGconn *conn)
 						if (!conn->result)
 							return;
 					}
-					strncpy(conn->result->cmdStatus, conn->workBuffer.data,
+					strlcpy(conn->result->cmdStatus, conn->workBuffer.data,
 							CMDSTATUS_LEN);
 					conn->asyncStatus = PGASYNC_READY;
 					break;
diff --git a/src/port/exec.c b/src/port/exec.c
@@ -88,7 +88,7 @@ validate_exec(const char *path)
 	if (strlen(path) >= strlen(".exe") &&
 		pg_strcasecmp(path + strlen(path) - strlen(".exe"), ".exe") != 0)
 	{
-		strcpy(path_exe, path);
+		strlcpy(path_exe, path, sizeof(path_exe) - 4);
 		strcat(path_exe, ".exe");
 		path = path_exe;
 	}
@@ -345,7 +345,7 @@ resolve_symlinks(char *path)
 	}
 
 	/* must copy final component out of 'path' temporarily */
-	strcpy(link_buf, fname);
+	strlcpy(link_buf, fname, sizeof(link_buf));
 
 	if (!getcwd(path, MAXPGPATH))
 	{
diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
@@ -1227,7 +1227,7 @@ results_differ(const char *testname, const char *resultsfile, const char *defaul
 	 */
 	platform_expectfile = get_expectfile(testname, resultsfile);
 
-	strcpy(expectfile, default_expectfile);
+	strlcpy(expectfile, default_expectfile, sizeof(expectfile));
 	if (platform_expectfile)
 	{
 		/*
@@ -1282,7 +1282,7 @@ results_differ(const char *testname, const char *resultsfile, const char *defaul
 		{
 			/* This diff was a better match than the last one */
 			best_line_count = l;
-			strcpy(best_expect_file, alt_expectfile);
+			strlcpy(best_expect_file, alt_expectfile, sizeof(best_expect_file));
 		}
 		free(alt_expectfile);
 	}
@@ -1310,7 +1310,7 @@ results_differ(const char *testname, const char *resultsfile, const char *defaul
 		{
 			/* This diff was a better match than the last one */
 			best_line_count = l;
-			strcpy(best_expect_file, default_expectfile);
+			strlcpy(best_expect_file, default_expectfile, sizeof(best_expect_file));
 		}
 	}
 
diff --git a/src/timezone/pgtz.c b/src/timezone/pgtz.c
@@ -94,7 +94,7 @@ pg_open_tzfile(const char *name, char *canonname)
 	 * Loop to split the given name into directory levels; for each level,
 	 * search using scan_directory_ci().
 	 */
-	strcpy(fullname, pg_TZDIR());
+	strlcpy(fullname, pg_TZDIR(), sizeof(fullname));
 	orignamelen = fullnamelen = strlen(fullname);
 	fname = name;
 	for (;;)
@@ -428,7 +428,7 @@ identify_system_timezone(void)
 	}
 
 	/* Search for the best-matching timezone file */
-	strcpy(tmptzdir, pg_TZDIR());
+	strlcpy(tmptzdir, pg_TZDIR(), sizeof(tmptzdir));
 	bestscore = -1;
 	resultbuf[0] = '\0';
 	scan_available_timezones(tmptzdir, tmptzdir + strlen(tmptzdir) + 1,

Original file line number	Diff line number	Diff line change
`@@ -337,7 +337,7 @@ SetWALFileNameForCleanup(void)`
`337`	`337`	`if (strcmp(restartWALFileName, nextWALFileName) > 0)`
`338`	`338`	`return false;`
`339`	`339`
`340`		`- strcpy(exclusiveCleanupFileName, restartWALFileName);`
	`340`	`+ strlcpy(exclusiveCleanupFileName, restartWALFileName, sizeof(exclusiveCleanupFileName));`
`341`	`341`	`return true;`
`342`	`342`	`}`
`343`	`343`
Original file line number	Diff line number	Diff line change
`@@ -181,7 +181,7 @@ NIAddSpell(IspellDict Conf, const char word, const char *flag)`
`181`	`181`	`}`
`182`	`182`	`Conf->Spell[Conf->nspell] = (SPELL *) tmpalloc(SPELLHDRSZ + strlen(word) + 1);`
`183`	`183`	`strcpy(Conf->Spell[Conf->nspell]->word, word);`
`184`		`- strncpy(Conf->Spell[Conf->nspell]->p.flag, flag, MAXFLAGLEN);`
	`184`	`+ strlcpy(Conf->Spell[Conf->nspell]->p.flag, flag, MAXFLAGLEN);`
`185`	`185`	`Conf->nspell++;`
`186`	`186`	`}`
`187`	`187`
Original file line number	Diff line number	Diff line change
`@@ -1270,7 +1270,7 @@ parse_include(void)`
`1270`	`1270`	`yytext[i] = '\0';`
`1271`	`1271`	`memmove(yytext, yytext+1, strlen(yytext));`
`1272`	`1272`
`1273`		`- strncpy(inc_file, yytext, sizeof(inc_file));`
	`1273`	`+ strlcpy(inc_file, yytext, sizeof(inc_file));`
`1274`	`1274`	`yyin = fopen(inc_file, "r");`
`1275`	`1275`	`if (!yyin)`
`1276`	`1276`	`{`
Original file line number	Diff line number	Diff line change
`@@ -440,7 +440,7 @@ pqParseInput2(PGconn *conn)`
`440`	`440`	`if (!conn->result)`
`441`	`441`	`return;`
`442`	`442`	`}`
`443`		`- strncpy(conn->result->cmdStatus, conn->workBuffer.data,`
	`443`	`+ strlcpy(conn->result->cmdStatus, conn->workBuffer.data,`
`444`	`444`	`CMDSTATUS_LEN);`
`445`	`445`	`checkXactStatus(conn, conn->workBuffer.data);`
`446`	`446`	`conn->asyncStatus = PGASYNC_READY;`
Original file line number	Diff line number	Diff line change
`@@ -206,7 +206,7 @@ pqParseInput3(PGconn *conn)`
`206`	`206`	`if (!conn->result)`
`207`	`207`	`return;`
`208`	`208`	`}`
`209`		`- strncpy(conn->result->cmdStatus, conn->workBuffer.data,`
	`209`	`+ strlcpy(conn->result->cmdStatus, conn->workBuffer.data,`
`210`	`210`	`CMDSTATUS_LEN);`
`211`	`211`	`conn->asyncStatus = PGASYNC_READY;`
`212`	`212`	`break;`
Original file line number	Diff line number	Diff line change
`@@ -88,7 +88,7 @@ validate_exec(const char *path)`
`88`	`88`	`if (strlen(path) >= strlen(".exe") &&`
`89`	`89`	`pg_strcasecmp(path + strlen(path) - strlen(".exe"), ".exe") != 0)`
`90`	`90`	`{`
`91`		`- strcpy(path_exe, path);`
	`91`	`+ strlcpy(path_exe, path, sizeof(path_exe) - 4);`
`92`	`92`	`strcat(path_exe, ".exe");`
`93`	`93`	`path = path_exe;`
`94`	`94`	`}`
`@@ -345,7 +345,7 @@ resolve_symlinks(char *path)`
`345`	`345`	`}`
`346`	`346`
`347`	`347`	`/* must copy final component out of 'path' temporarily */`
`348`		`- strcpy(link_buf, fname);`
	`348`	`+ strlcpy(link_buf, fname, sizeof(link_buf));`
`349`	`349`
`350`	`350`	`if (!getcwd(path, MAXPGPATH))`
`351`	`351`	`{`
Original file line number	Diff line number	Diff line change
`@@ -1227,7 +1227,7 @@ results_differ(const char testname, const char resultsfile, const char *defaul`
`1227`	`1227`	`*/`
`1228`	`1228`	`platform_expectfile = get_expectfile(testname, resultsfile);`
`1229`	`1229`
`1230`		`- strcpy(expectfile, default_expectfile);`
	`1230`	`+ strlcpy(expectfile, default_expectfile, sizeof(expectfile));`
`1231`	`1231`	`if (platform_expectfile)`
`1232`	`1232`	`{`
`1233`	`1233`	`/*`
`@@ -1282,7 +1282,7 @@ results_differ(const char testname, const char resultsfile, const char *defaul`
`1282`	`1282`	`{`
`1283`	`1283`	`/* This diff was a better match than the last one */`
`1284`	`1284`	`best_line_count = l;`
`1285`		`- strcpy(best_expect_file, alt_expectfile);`
	`1285`	`+ strlcpy(best_expect_file, alt_expectfile, sizeof(best_expect_file));`
`1286`	`1286`	`}`
`1287`	`1287`	`free(alt_expectfile);`
`1288`	`1288`	`}`
`@@ -1310,7 +1310,7 @@ results_differ(const char testname, const char resultsfile, const char *defaul`
`1310`	`1310`	`{`
`1311`	`1311`	`/* This diff was a better match than the last one */`
`1312`	`1312`	`best_line_count = l;`
`1313`		`- strcpy(best_expect_file, default_expectfile);`
	`1313`	`+ strlcpy(best_expect_file, default_expectfile, sizeof(best_expect_file));`
`1314`	`1314`	`}`
`1315`	`1315`	`}`
`1316`	`1316`