diff --git a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp index 5da0f34b3d046..8ebedc1269dc1 100644 --- a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp @@ -743,12 +743,14 @@ void GenericTaintChecker::initTaintRules(CheckerContext &C) const { // Sinks {{{"system"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, {{{"popen"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, - {{{"execl"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, - {{{"execle"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, - {{{"execlp"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, - {{{"execvp"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, - {{{"execvP"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, - {{{"execve"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, + {{{"execl"}}, TR::Sink({{}, {0}}, MsgSanitizeSystemArgs)}, + {{{"execle"}}, TR::Sink({{}, {0}}, MsgSanitizeSystemArgs)}, + {{{"execlp"}}, TR::Sink({{}, {0}}, MsgSanitizeSystemArgs)}, + {{{"execv"}}, TR::Sink({{0, 1}}, MsgSanitizeSystemArgs)}, + {{{"execve"}}, TR::Sink({{0, 1, 2}}, MsgSanitizeSystemArgs)}, + {{{"fexecve"}}, TR::Sink({{0, 1, 2}}, MsgSanitizeSystemArgs)}, + {{{"execvp"}}, TR::Sink({{0, 1}}, MsgSanitizeSystemArgs)}, + {{{"execvpe"}}, TR::Sink({{0, 1, 2}}, MsgSanitizeSystemArgs)}, {{{"dlopen"}}, TR::Sink({{0}}, MsgSanitizeSystemArgs)}, {{CDF_MaybeBuiltin, {{"malloc"}}}, TR::Sink({{0}}, MsgTaintedBufferSize)}, {{CDF_MaybeBuiltin, {{"calloc"}}}, TR::Sink({{0}}, MsgTaintedBufferSize)}, diff --git a/clang/test/Analysis/taint-generic.c b/clang/test/Analysis/taint-generic.c index f08186fc8c4c1..dbe954d597054 100644 --- a/clang/test/Analysis/taint-generic.c +++ b/clang/test/Analysis/taint-generic.c @@ -63,6 +63,8 @@ void clang_analyzer_isTainted_wchar(wchar_t); void clang_analyzer_isTainted_charp(char*); void clang_analyzer_isTainted_int(int); +int coin(); + int scanf(const char *restrict format, ...); char *gets(char *str); char *gets_s(char *str, rsize_t n); @@ -119,6 +121,41 @@ void *malloc(size_t); void *calloc(size_t nmemb, size_t size); void bcopy(void *s1, void *s2, size_t n); + +// function | pathname | filename | fd | arglist | argv[] | envp[] +// =============================================================== +// 1 execl | X | | | X | | +// 2 execle | X | | | X | | X +// 3 execlp | | X | | X | | +// 4 execv | X | | | | X | +// 5 execve | X | | | | X | X +// 6 execvp | | X | | | X | +// 7 execvpe | | X | | | X | X +// 8 fexecve | | | X | | X | X +// =============================================================== +// letter | | p | f | l | v | e +// +// legend: +// - pathname: rel/abs path to the binary +// - filename: file name searched in PATH to execute the binary +// - fd: accepts a file descriptor +// - arglist: accepts variadic arguments +// - argv: accepts a pointer to array, denoting the new argv +// - envp: accepts a pointer to array, denoting the new envp + +int execl(const char *path, const char *arg, ...); +int execle(const char *path, const char *arg, ...); +int execlp(const char *file, const char *arg, ...); +int execv(const char *path, char *const argv[]); +int execve(const char *path, char *const argv[], char *const envp[]); +int execvp(const char *file, char *const argv[]); +int execvpe(const char *file, char *const argv[], char *const envp[]); +int fexecve(int fd, char *const argv[], char *const envp[]); +FILE *popen(const char *command, const char *type); +int pclose(FILE *stream); +int system(const char *command); + + typedef size_t socklen_t; struct sockaddr { @@ -225,7 +262,6 @@ void testUncontrolledFormatString(char **p) { } -int system(const char *command); void testTaintSystemCall(void) { char buffer[156]; char addr[128]; @@ -288,7 +324,6 @@ void testTaintedBufferSize(void) { #define SOCK_STREAM 1 int socket(int, int, int); size_t read(int, void *, size_t); -int execl(const char *, const char *, ...); void testSocket(void) { int sock; @@ -1120,6 +1155,128 @@ void testConfigurationSinks(void) { // expected-warning@-1 {{Untrusted data is passed to a user-defined sink}} } +int test_exec_like_functions() { + char buf[100] = {0}; + scanf("%99s", buf); + clang_analyzer_isTainted_char(buf[0]); // expected-warning {{YES}} + + char *cleanArray[] = {"ENV1=V1", "ENV2=V2", NULL}; + char *taintedArray[] = {buf, "ENV2=V2", NULL}; + clang_analyzer_isTainted_char(taintedArray[0][0]); // expected-warning {{YES}} + clang_analyzer_isTainted_char(*(char*)taintedArray[0]); // expected-warning {{YES}} + clang_analyzer_isTainted_char(*(char*)taintedArray); // expected-warning {{NO}} We should have YES here. + // FIXME: Above the triple pointer indirection will confuse the checker, + // as we only check two levels. The results would be worse, if the tainted + // subobject ("buf") would not be at the beginning of the enclosing object, + // for the same reason. + + switch (coin()) { + default: break; + // Execute `path` with all arguments after `path` until a NULL pointer + // and environment from `environ'. + case 0: return execl("path", "arg0", "arg1", "arg2", NULL); // no-warning + case 1: return execl(buf, "arg0", "arg1", "arg2", NULL); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return execl("path", buf, "arg1", "arg2", NULL); // expected-warning {{Untrusted data is passed to a system call}} + case 3: return execl("path", "arg0", buf, "arg2", NULL); // expected-warning {{Untrusted data is passed to a system call}} + case 4: return execl("path", "arg0", "arg1", buf, NULL); // expected-warning {{Untrusted data is passed to a system call}} + } + + switch (coin()) { + default: break; + // Execute `path` with all arguments after `PATH` until a NULL pointer, + // and the argument after that for environment. + case 0: return execle("path", "arg0", "arg1", NULL, cleanArray); // no-warning + case 1: return execle( buf, "arg0", "arg1", NULL, cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return execle("path", buf, "arg1", NULL, cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 3: return execle("path", "arg0", buf, NULL, cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 4: return execle("path", "arg0", "arg1", NULL, buf); // expected-warning {{Untrusted data is passed to a system call}} + case 5: return execle("path", "arg0", "arg1", NULL, taintedArray); // FIXME: We might wanna have a report here. + } + + switch (coin()) { + default: break; + // Execute `file`, searching in the `PATH' environment variable if it + // contains no slashes, with all arguments after `file` until a NULL + // pointer and environment from `environ'. + case 0: return execlp("file", "arg0", "arg1", "arg2", NULL); // no-warning + case 1: return execlp( buf, "arg0", "arg1", "arg2", NULL); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return execlp("file", buf, "arg1", "arg2", NULL); // expected-warning {{Untrusted data is passed to a system call}} + case 3: return execlp("file", "arg0", buf, "arg2", NULL); // expected-warning {{Untrusted data is passed to a system call}} + case 4: return execlp("file", "arg0", "arg1", buf, NULL); // expected-warning {{Untrusted data is passed to a system call}} + } + + switch (coin()) { + default: break; + // Execute `path` with arguments `ARGV` and environment from `environ'. + case 0: return execv("path", /*argv=*/ cleanArray); // no-warning + case 1: return execv( buf, /*argv=*/ cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return execv("path", /*argv=*/taintedArray); // FIXME: We might wanna have a report here. + } + + switch (coin()) { + default: break; + // Replace the current process, executing `path` with arguments `ARGV` + // and environment `ENVP`. `ARGV` and `ENVP` are terminated by NULL pointers. + case 0: return execve("path", /*argv=*/ cleanArray, /*envp=*/cleanArray); // no-warning + case 1: return execve( buf, /*argv=*/ cleanArray, /*envp=*/cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return execve("path", /*argv=*/taintedArray, /*envp=*/cleanArray); // FIXME: We might wanna have a report here. + case 3: return execve("path", /*argv=*/cleanArray, /*envp=*/taintedArray); // FIXME: We might wanna have a report here. + } + + switch (coin()) { + default: break; + // Execute `file`, searching in the `PATH' environment variable if it + // contains no slashes, with arguments `ARGV` and environment from `environ'. + case 0: return execvp("file", /*argv=*/ cleanArray); // no-warning + case 1: return execvp( buf, /*argv=*/ cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return execvp("file", /*argv=*/taintedArray); // FIXME: We might wanna have a report here. + } + + // execvpe + switch (coin()) { + default: break; + // Execute `file`, searching in the `PATH' environment variable if it + // contains no slashes, with arguments `ARGV` and environment `ENVP`. + // `ARGV` and `ENVP` are terminated by NULL pointers. + case 0: return execvpe("file", /*argv=*/ cleanArray, /*envp=*/ cleanArray); // no-warning + case 1: return execvpe( buf, /*argv=*/ cleanArray, /*envp=*/ cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return execvpe("file", /*argv=*/taintedArray, /*envp=*/ cleanArray); // FIXME: We might wanna have a report here. + case 3: return execvpe("file", /*argv=*/ cleanArray, /*envp=*/taintedArray); // FIXME: We might wanna have a report here. + } + + int cleanFD = coin(); + int taintedFD; + scanf("%d", &taintedFD); + clang_analyzer_isTainted_int(taintedFD); // expected-warning {{YES}} + + switch (coin()) { + default: break; + // Execute the file `FD` refers to, overlaying the running program image. + // `ARGV` and `ENVP` are passed to the new program, as for `execve'. + case 0: return fexecve( cleanFD, /*argv=*/ cleanArray, /*envp=*/ cleanArray); // no-warning + case 1: return fexecve(taintedFD, /*argv=*/ cleanArray, /*envp=*/ cleanArray); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return fexecve( cleanFD, /*argv=*/taintedArray, /*envp=*/ cleanArray); // FIXME: We might wanna have a report here. + case 3: return fexecve( cleanFD, /*argv=*/ cleanArray, /*envp=*/taintedArray); // FIXME: We might wanna have a report here. + } + + switch (coin()) { + default: break; + // Create a new stream connected to a pipe running the given `command`. + case 0: return pclose(popen("command", /*mode=*/"r")); // no-warning + case 1: return pclose(popen( buf, /*mode=*/"r")); // expected-warning {{Untrusted data is passed to a system call}} + case 2: return pclose(popen("command", /*mode=*/buf)); // 'mode' is not a taint sink. + } + + switch (coin()) { + default: break; + // Execute the given line as a shell command. + case 0: return system("command"); // no-warning + case 1: return system( buf); // expected-warning {{Untrusted data is passed to a system call}} + } + + return 0; +} + void testUnknownFunction(void (*foo)(void)) { foo(); // no-crash }