Bug Summary

File:src/bin/ksh/main.c
Warning:line 785, column 13
Access to field 'oenv' results in a dereference of a null pointer (loaded from variable 'genv')

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name main.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/bin/ksh/obj -resource-dir /usr/local/lib/clang/13.0.0 -D EMACS -D VI -I . -I /usr/src/bin/ksh -I /usr/src/bin/ksh/../../lib/libc/gen -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/bin/ksh/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/bin/ksh/main.c
1/* $OpenBSD: main.c,v 1.98 2019/06/28 13:34:59 deraadt Exp $ */
2
3/*
4 * startup, main loop, environments and error handling
5 */
6
7#include <sys/stat.h>
8
9#include <errno(*__errno()).h>
10#include <fcntl.h>
11#include <paths.h>
12#include <pwd.h>
13#include <stdio.h>
14#include <stdlib.h>
15#include <string.h>
16#include <unistd.h>
17
18#include "sh.h"
19
20extern char **environ;
21
22/*
23 * global data
24 */
25
26static void reclaim(void);
27static void remove_temps(struct temp *tp);
28static int is_restricted(char *name);
29static void init_username(void);
30
31const char *kshname;
32pid_t kshpid;
33pid_t procpid;
34uid_t ksheuid;
35int exstat;
36int subst_exstat;
37const char *safe_prompt;
38int disable_subst;
39
40Area aperm;
41
42struct env *genv;
43
44char shell_flags[FNFLAGS];
45
46char null[] = "";
47
48int shl_stdout_ok;
49
50unsigned int ksh_tmout;
51enum tmout_enum ksh_tmout_state = TMOUT_EXECUTING;
52
53int really_exit;
54
55int ifs0 = ' ';
56
57volatile sig_atomic_t trap;
58volatile sig_atomic_t intrsig;
59volatile sig_atomic_t fatal_trap;
60
61Getopt builtin_opt;
62Getopt user_opt;
63
64struct coproc coproc;
65sigset_t sm_default, sm_sigchld;
66
67char *builtin_argv0;
68int builtin_flag;
69
70char *current_wd;
71int current_wd_size;
72
73int x_cols = 80;
74
75/*
76 * shell initialization
77 */
78
79static const char initifs[] = "IFS= \t\n";
80
81static const char initsubs[] = "${PS2=> } ${PS3=#? } ${PS4=+ }";
82
83static const char *initcoms [] = {
84 "typeset", "-r", "KSH_VERSION", NULL((void*)0),
85 "typeset", "-x", "SHELL", "PATH", "HOME", "PWD", "OLDPWD", NULL((void*)0),
86 "typeset", "-ir", "PPID", NULL((void*)0),
87 "typeset", "-i", "OPTIND=1", NULL((void*)0),
88 "eval", "typeset -i RANDOM MAILCHECK=\"${MAILCHECK-600}\" SECONDS=\"${SECONDS-0}\" TMOUT=\"${TMOUT-0}\"", NULL((void*)0),
89 "alias",
90 /* Standard ksh aliases */
91 "hash=alias -t", /* not "alias -t --": hash -r needs to work */
92 "stop=kill -STOP",
93 "autoload=typeset -fu",
94 "functions=typeset -f",
95 "history=fc -l",
96 "integer=typeset -i",
97 "nohup=nohup ",
98 "local=typeset",
99 "r=fc -s",
100 /* Aliases that are builtin commands in at&t */
101 "login=exec login",
102 NULL((void*)0),
103 /* this is what at&t ksh seems to track, with the addition of emacs */
104 "alias", "-tU",
105 "cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
106 "mail", "make", "mv", "pr", "rm", "sed", "sh", "vi", "who",
107 NULL((void*)0),
108 NULL((void*)0)
109};
110
111char username[_PW_NAME_LEN31 + 1];
112
113#define version_param(initcoms[2]) (initcoms[2])
114
115/* The shell uses its own variation on argv, to build variables like
116 * $0 and $@.
117 * Allocate a new array since modifying the original argv will modify
118 * ps output.
119 */
120static char **
121make_argv(int argc, char *argv[])
122{
123 int i;
124 char **nargv;
125
126 nargv = areallocarray(NULL((void*)0), argc + 1, sizeof(char *), &aperm);
127 nargv[0] = (char *) kshname;
128 for (i = 1; i < argc; i++)
129 nargv[i] = argv[i];
130 nargv[i] = NULL((void*)0);
131
132 return nargv;
133}
134
135int
136main(int argc, char *argv[])
137{
138 int i;
139 int argi;
140 Source *s;
141 struct block *l;
142 int restricted, errexit;
143 char **wp;
144 struct env env;
145 pid_t ppid;
146
147 kshname = argv[0];
148
149 if (issetugid()) { /* could later drop privileges */
150 if (pledge("stdio rpath wpath cpath fattr flock getpw proc "
151 "exec tty id", NULL((void*)0)) == -1) {
152 perror("pledge");
153 exit(1);
154 }
155 } else {
156 if (pledge("stdio rpath wpath cpath fattr flock getpw proc "
157 "exec tty", NULL((void*)0)) == -1) {
158 perror("pledge");
159 exit(1);
160 }
161 }
162
163 ainit(&aperm); /* initialize permanent Area */
164
165 /* set up base environment */
166 memset(&env, 0, sizeof(env));
167 env.type = E_NONE0;
168 ainit(&env.area);
169 genv = &env;
170 newblock(); /* set up global l->vars and l->funs */
171
172 /* Do this first so output routines (eg, errorf, shellf) can work */
173 initio();
174
175 initvar();
176
177 initctypes();
178
179 inittraps();
180
181 coproc_init();
182
183 /* set up variable and command dictionaries */
184 ktinit(&taliases, APERM&aperm, 0);
185 ktinit(&aliases, APERM&aperm, 0);
186 ktinit(&homedirs, APERM&aperm, 0);
187
188 /* define shell keywords */
189 initkeywords();
190
191 /* define built-in commands */
192 ktinit(&builtins, APERM&aperm, 64); /* must be 2^n (currently 40 builtins) */
193 for (i = 0; shbuiltins[i].name != NULL((void*)0); i++)
194 builtin(shbuiltins[i].name, shbuiltins[i].func);
195 for (i = 0; kshbuiltins[i].name != NULL((void*)0); i++)
196 builtin(kshbuiltins[i].name, kshbuiltins[i].func);
197
198 init_histvec();
199
200 def_path = _PATH_DEFPATH"/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin";
201 {
202 size_t len = confstr(_CS_PATH1, NULL((void*)0), 0);
203 char *new;
204
205 if (len > 0) {
206 confstr(_CS_PATH1, new = alloc(len + 1, APERM&aperm), len + 1);
207 def_path = new;
208 }
209 }
210
211 /* Set PATH to def_path (will set the path global variable).
212 * (import of environment below will probably change this setting).
213 */
214 {
215 struct tbl *vp = global("PATH");
216 /* setstr can't fail here */
217 setstr(vp, def_path, KSH_RETURN_ERROR0x1);
218 }
219
220
221 /* Turn on nohup by default for now - will change to off
222 * by default once people are aware of its existence
223 * (at&t ksh does not have a nohup option - it always sends
224 * the hup).
225 */
226 Flag(FNOHUP)(shell_flags[(int) (FNOHUP)]) = 1;
227
228 /* Turn on brace expansion by default. At&t ksh's that have
229 * alternation always have it on. BUT, posix doesn't have
230 * brace expansion, so set this before setting up FPOSIX
231 * (change_flag() clears FBRACEEXPAND when FPOSIX is set).
232 */
233 Flag(FBRACEEXPAND)(shell_flags[(int) (FBRACEEXPAND)]) = 1;
234
235 /* set posix flag just before environment so that it will have
236 * exactly the same effect as the POSIXLY_CORRECT environment
237 * variable. If this needs to be done sooner to ensure correct posix
238 * operation, an initial scan of the environment will also have
239 * done sooner.
240 */
241#ifdef POSIXLY_CORRECT
242 change_flag(FPOSIX, OF_SPECIAL0x04, 1);
243#endif /* POSIXLY_CORRECT */
244
245 /* Check to see if we're /bin/sh. */
246 if (!strcmp(kshname, "sh") || !strcmp(kshname, "-sh") ||
247 (strlen(kshname) >= 3 &&
248 !strcmp(&kshname[strlen(kshname) - 3], "/sh"))) {
249 Flag(FSH)(shell_flags[(int) (FSH)]) = 1;
250 version_param(initcoms[2]) = "SH_VERSION";
251 }
252
253 /* Set edit mode to emacs by default, may be overridden
254 * by the environment or the user. Also, we want tab completion
255 * on in vi by default. */
256#if defined(EMACS1)
257 change_flag(FEMACS, OF_SPECIAL0x04, 1);
258#endif /* EMACS */
259#if defined(VI1)
260 Flag(FVITABCOMPLETE)(shell_flags[(int) (FVITABCOMPLETE)]) = 1;
261#endif /* VI */
262
263 /* import environment */
264 if (environ != NULL((void*)0))
265 for (wp = environ; *wp != NULL((void*)0); wp++)
266 typeset(*wp, IMPORT(1<<(21))|EXPORT(1<<(3)), 0, 0, 0);
267
268 kshpid = procpid = getpid();
269 typeset(initifs, 0, 0, 0, 0); /* for security */
270
271 /* assign default shell variable values */
272 substitute(initsubs, 0);
273
274 /* Figure out the current working directory and set $PWD */
275 {
276 struct stat s_pwd, s_dot;
277 struct tbl *pwd_v = global("PWD");
278 char *pwd = str_val(pwd_v);
279 char *pwdx = pwd;
280
281 /* Try to use existing $PWD if it is valid */
282 if (pwd[0] != '/' ||
283 stat(pwd, &s_pwd) == -1 || stat(".", &s_dot) == -1 ||
284 s_pwd.st_dev != s_dot.st_dev ||
285 s_pwd.st_ino != s_dot.st_ino)
286 pwdx = NULL((void*)0);
287 set_current_wd(pwdx);
288 if (current_wd[0])
289 simplify_path(current_wd);
290 /* Only set pwd if we know where we are or if it had a
291 * bogus value
292 */
293 if (current_wd[0] || pwd != null)
294 /* setstr can't fail here */
295 setstr(pwd_v, current_wd, KSH_RETURN_ERROR0x1);
296 }
297 ppid = getppid();
298 setint(global("PPID"), (int64_t) ppid);
299 /* setstr can't fail here */
300 setstr(global(version_param(initcoms[2])), ksh_version, KSH_RETURN_ERROR0x1);
301
302 /* execute initialization statements */
303 for (wp = (char**) initcoms; *wp != NULL((void*)0); wp++) {
304 shcomexec(wp);
305 for (; *wp != NULL((void*)0); wp++)
306 ;
307 }
308
309
310 ksheuid = geteuid();
311 init_username();
312 safe_prompt = ksheuid ? "$ " : "# ";
313 {
314 struct tbl *vp = global("PS1");
315
316 /* Set PS1 if it isn't set */
317 if (!(vp->flag & ISSET(1<<(2)))) {
318 /* setstr can't fail here */
319 setstr(vp, "\\h\\$ ", KSH_RETURN_ERROR0x1);
320 }
321 }
322
323 /* Set this before parsing arguments */
324 Flag(FPRIVILEGED)(shell_flags[(int) (FPRIVILEGED)]) = getuid() != ksheuid || getgid() != getegid();
325
326 /* this to note if monitor is set on command line (see below) */
327 Flag(FMONITOR)(shell_flags[(int) (FMONITOR)]) = 127;
328 argi = parse_args(argv, OF_CMDLINE0x01, NULL((void*)0));
329 if (argi < 0)
330 exit(1);
331
332 if (Flag(FCOMMAND)(shell_flags[(int) (FCOMMAND)])) {
333 s = pushs(SSTRING3, ATEMP&genv->area);
334 if (!(s->start = s->str = argv[argi++]))
335 errorf("-c requires an argument");
336 if (argv[argi])
337 kshname = argv[argi++];
338 } else if (argi < argc && !Flag(FSTDIN)(shell_flags[(int) (FSTDIN)])) {
339 s = pushs(SFILE1, ATEMP&genv->area);
340 s->file = argv[argi++];
341 s->u.shf = shf_open(s->file, O_RDONLY0x0000, 0, SHF_MAPHI0x0020|SHF_CLEXEC0x0010);
342 if (s->u.shf == NULL((void*)0)) {
343 exstat = 127; /* POSIX */
344 errorf("%s: %s", s->file, strerror(errno(*__errno())));
345 }
346 kshname = s->file;
347 } else {
348 Flag(FSTDIN)(shell_flags[(int) (FSTDIN)]) = 1;
349 s = pushs(SSTDIN2, ATEMP&genv->area);
350 s->file = "<stdin>";
351 s->u.shf = shf_fdopen(0, SHF_RD0x0001 | can_seek(0), NULL((void*)0));
352 if (isatty(0) && isatty(2)) {
353 Flag(FTALKING)(shell_flags[(int) (FTALKING)]) = Flag(FTALKING_I)(shell_flags[(int) (FTALKING_I)]) = 1;
354 /* The following only if isatty(0) */
355 s->flags |= SF_TTY(1<<(3));
356 s->u.shf->flags |= SHF_INTERRUPT0x0080;
357 s->file = NULL((void*)0);
358 }
359 }
360
361 /* This bizarreness is mandated by POSIX */
362 {
363 struct stat s_stdin;
364
365 if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode)((s_stdin.st_mode & 0170000) == 0020000) &&
366 Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
367 reset_nonblock(0);
368 }
369
370 /* initialize job control */
371 i = Flag(FMONITOR)(shell_flags[(int) (FMONITOR)]) != 127;
372 Flag(FMONITOR)(shell_flags[(int) (FMONITOR)]) = 0;
373 j_init(i);
374 /* Do this after j_init(), as tty_fd is not initialized 'til then */
375 if (Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
376 x_init();
377
378 l = genv->loc;
379 l->argv = make_argv(argc - (argi - 1), &argv[argi - 1]);
380 l->argc = argc - argi;
381 getopts_reset(1);
382
383 /* Disable during .profile/ENV reading */
384 restricted = Flag(FRESTRICTED)(shell_flags[(int) (FRESTRICTED)]);
385 Flag(FRESTRICTED)(shell_flags[(int) (FRESTRICTED)]) = 0;
386 errexit = Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]);
387 Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) = 0;
388
389 /* Do this before profile/$ENV so that if it causes problems in them,
390 * user will know why things broke.
391 */
392 if (!current_wd[0] && Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
393 warningf(false0, "Cannot determine current working directory");
394
395 if (Flag(FLOGIN)(shell_flags[(int) (FLOGIN)])) {
396 include(KSH_SYSTEM_PROFILE"/etc/profile", 0, NULL((void*)0), 1);
397 if (!Flag(FPRIVILEGED)(shell_flags[(int) (FPRIVILEGED)]))
398 include(substitute("$HOME/.profile", 0), 0, NULL((void*)0), 1);
399 }
400
401 if (Flag(FPRIVILEGED)(shell_flags[(int) (FPRIVILEGED)]))
402 include("/etc/suid_profile", 0, NULL((void*)0), 1);
403 else if (Flag(FTALKING)(shell_flags[(int) (FTALKING)])) {
404 char *env_file;
405
406 /* include $ENV */
407 env_file = str_val(global("ENV"));
408
409#ifdef DEFAULT_ENV
410 /* If env isn't set, include default environment */
411 if (env_file == null)
412 env_file = DEFAULT_ENV;
413#endif /* DEFAULT_ENV */
414 env_file = substitute(env_file, DOTILDE(1<<(3)));
415 if (*env_file != '\0')
416 include(env_file, 0, NULL((void*)0), 1);
417 }
418
419 if (is_restricted(argv[0]) || is_restricted(str_val(global("SHELL"))))
420 restricted = 1;
421 if (restricted) {
422 static const char *const restr_com[] = {
423 "typeset", "-r", "PATH",
424 "ENV", "SHELL",
425 NULL((void*)0)
426 };
427 shcomexec((char **) restr_com);
428 /* After typeset command... */
429 Flag(FRESTRICTED)(shell_flags[(int) (FRESTRICTED)]) = 1;
430 }
431 if (errexit)
432 Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) = 1;
433
434 if (Flag(FTALKING)(shell_flags[(int) (FTALKING)])) {
435 hist_init(s);
436 alarm_init();
437 } else
438 Flag(FTRACKALL)(shell_flags[(int) (FTRACKALL)]) = 1; /* set after ENV */
439
440 shell(s, true1); /* doesn't return */
441 return 0;
442}
443
444static void
445init_username(void)
446{
447 char *p;
448 struct tbl *vp = global("USER");
449
450 if (vp->flag & ISSET(1<<(2)))
451 p = ksheuid == 0 ? "root" : str_val(vp);
452 else
453 p = getlogin();
454
455 strlcpy(username, p != NULL((void*)0) ? p : "?", sizeof username);
456}
457
458int
459include(const char *name, int argc, char **argv, int intr_ok)
460{
461 Source *volatile s = NULL((void*)0);
462 struct shf *shf;
463 char **volatile old_argv;
464 volatile int old_argc;
465 int i;
466
467 shf = shf_open(name, O_RDONLY0x0000, 0, SHF_MAPHI0x0020|SHF_CLEXEC0x0010);
468 if (shf == NULL((void*)0))
469 return -1;
470
471 if (argv) {
472 old_argv = genv->loc->argv;
473 old_argc = genv->loc->argc;
474 } else {
475 old_argv = NULL((void*)0);
476 old_argc = 0;
477 }
478 newenv(E_INCL3);
479 i = sigsetjmp(genv->jbuf, 0);
480 if (i) {
481 quitenv(s ? s->u.shf : NULL((void*)0));
482 if (old_argv) {
483 genv->loc->argv = old_argv;
484 genv->loc->argc = old_argc;
485 }
486 switch (i) {
487 case LRETURN1:
488 case LERROR3:
489 return exstat & 0xff; /* see below */
490 case LINTR5:
491 /* intr_ok is set if we are including .profile or $ENV.
492 * If user ^C's out, we don't want to kill the shell...
493 */
494 if (intr_ok && (exstat - 128) != SIGTERM15)
495 return 1;
496 /* FALLTHROUGH */
497 case LEXIT2:
498 case LLEAVE4:
499 case LSHELL8:
500 unwind(i);
501 /* NOTREACHED */
502 default:
503 internal_errorf("%s: %d", __func__, i);
504 /* NOTREACHED */
505 }
506 }
507 if (argv) {
508 genv->loc->argv = argv;
509 genv->loc->argc = argc;
510 }
511 s = pushs(SFILE1, ATEMP&genv->area);
512 s->u.shf = shf;
513 s->file = str_save(name, ATEMP&genv->area);
514 i = shell(s, false0);
515 quitenv(s->u.shf);
516 if (old_argv) {
517 genv->loc->argv = old_argv;
518 genv->loc->argc = old_argc;
519 }
520 return i & 0xff; /* & 0xff to ensure value not -1 */
521}
522
523/*
524 * spawn a command into a shell optionally keeping track of line
525 * number.
526 */
527int
528command(const char *comm, int line)
529{
530 Source *s;
531
532 s = pushs(SSTRING3, ATEMP&genv->area);
533 s->start = s->str = comm;
534 s->line = line;
535 return shell(s, false0);
536}
537
538/*
539 * run the commands from the input source, returning status.
540 */
541int
542shell(Source *volatile s, volatile int toplevel)
543{
544 struct op *t;
545 volatile int wastty = s->flags & SF_TTY(1<<(3));
546 volatile int attempts = 13;
547 volatile int interactive = Flag(FTALKING)(shell_flags[(int) (FTALKING)]) && toplevel;
548 Source *volatile old_source = source;
549 int i;
550
551 newenv(E_PARSE1);
552 if (interactive)
553 really_exit = 0;
554 i = sigsetjmp(genv->jbuf, 0);
555 if (i) {
556 switch (i) {
557 case LINTR5: /* we get here if SIGINT not caught or ignored */
558 case LERROR3:
559 case LSHELL8:
560 if (interactive) {
561 c_fc_reset();
562 if (i == LINTR5)
563 shellf("\n");
564 /* Reset any eof that was read as part of a
565 * multiline command.
566 */
567 if (Flag(FIGNOREEOF)(shell_flags[(int) (FIGNOREEOF)]) && s->type == SEOF0 &&
568 wastty)
569 s->type = SSTDIN2;
570 /* Used by exit command to get back to
571 * top level shell. Kind of strange since
572 * interactive is set if we are reading from
573 * a tty, but to have stopped jobs, one only
574 * needs FMONITOR set (not FTALKING/SF_TTY)...
575 */
576 /* toss any input we have so far */
577 s->start = s->str = null;
578 break;
579 }
580 /* FALLTHROUGH */
581 case LEXIT2:
582 case LLEAVE4:
583 case LRETURN1:
584 source = old_source;
585 quitenv(NULL((void*)0));
586 unwind(i); /* keep on going */
587 /* NOTREACHED */
588 default:
589 source = old_source;
590 quitenv(NULL((void*)0));
591 internal_errorf("%s: %d", __func__, i);
592 /* NOTREACHED */
593 }
594 }
595
596 while (1) {
597 if (trap)
598 runtraps(0);
599
600 if (s->next == NULL((void*)0)) {
601 if (Flag(FVERBOSE)(shell_flags[(int) (FVERBOSE)]))
602 s->flags |= SF_ECHO(1<<(0));
603 else
604 s->flags &= ~SF_ECHO(1<<(0));
605 }
606
607 if (interactive) {
608 got_sigwinch = 1;
609 j_notify();
610 mcheck();
611 set_prompt(PS10);
612 }
613
614 t = compile(s);
615 if (t != NULL((void*)0) && t->type == TEOF0) {
616 if (wastty && Flag(FIGNOREEOF)(shell_flags[(int) (FIGNOREEOF)]) && --attempts > 0) {
617 shellf("Use `exit' to leave ksh\n");
618 s->type = SSTDIN2;
619 } else if (wastty && !really_exit &&
620 j_stopped_running()) {
621 really_exit = 1;
622 s->type = SSTDIN2;
623 } else {
624 /* this for POSIX, which says EXIT traps
625 * shall be taken in the environment
626 * immediately after the last command
627 * executed.
628 */
629 if (toplevel)
630 unwind(LEXIT2);
631 break;
632 }
633 }
634
635 if (t && (!Flag(FNOEXEC)(shell_flags[(int) (FNOEXEC)]) || (s->flags & SF_TTY(1<<(3)))))
636 exstat = execute(t, 0, NULL((void*)0));
637
638 if (t != NULL((void*)0) && t->type != TEOF0 && interactive && really_exit)
639 really_exit = 0;
640
641 reclaim();
642 }
643 quitenv(NULL((void*)0));
644 source = old_source;
645 return exstat;
646}
647
648/* return to closest error handler or shell(), exit if none found */
649void
650unwind(int i)
651{
652 /* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
653 if (i == LEXIT2 || (Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) && (i == LERROR3 || i == LINTR5) &&
654 sigtraps[SIGEXIT_0].trap)) {
655 if (trap)
656 runtraps(0);
657 runtrap(&sigtraps[SIGEXIT_0]);
658 i = LLEAVE4;
659 } else if (Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) && (i == LERROR3 || i == LINTR5)) {
660 if (trap)
661 runtraps(0);
662 runtrap(&sigtraps[SIGERR_33]);
663 i = LLEAVE4;
664 }
665 while (1) {
666 switch (genv->type) {
667 case E_PARSE1:
668 case E_FUNC2:
669 case E_INCL3:
670 case E_LOOP5:
671 case E_ERRH6:
672 siglongjmp(genv->jbuf, i);
673 /* NOTREACHED */
674
675 case E_NONE0:
676 if (i == LINTR5)
677 genv->flags |= EF_FAKE_SIGDIE(1<<(2));
678 /* FALLTHROUGH */
679
680 default:
681 quitenv(NULL((void*)0));
682 /*
683 * quitenv() may have reclaimed the memory
684 * used by source which will end badly when
685 * we jump to a function that expects it to
686 * be valid
687 */
688 source = NULL((void*)0);
689 }
690 }
691}
692
693void
694newenv(int type)
695{
696 struct env *ep;
697
698 ep = alloc(sizeof(*ep), ATEMP&genv->area);
699 ep->type = type;
700 ep->flags = 0;
701 ainit(&ep->area);
702 ep->loc = genv->loc;
703 ep->savefd = NULL((void*)0);
704 ep->oenv = genv;
705 ep->temps = NULL((void*)0);
706 genv = ep;
707}
708
709void
710quitenv(struct shf *shf)
711{
712 struct env *ep = genv;
713 int fd;
714
715 if (ep->oenv && ep->oenv->loc != ep->loc)
716 popblock();
717 if (ep->savefd != NULL((void*)0)) {
718 for (fd = 0; fd < NUFILE32; fd++)
719 /* if ep->savefd[fd] < 0, means fd was closed */
720 if (ep->savefd[fd])
721 restfd(fd, ep->savefd[fd]);
722 if (ep->savefd[2]) /* Clear any write errors */
723 shf_reopen(2, SHF_WR0x0002, shl_out(&shf_iob[2]));
724 }
725
726 /* Bottom of the stack.
727 * Either main shell is exiting or cleanup_parents_env() was called.
728 */
729 if (ep->oenv == NULL((void*)0)) {
730 if (ep->type == E_NONE0) { /* Main shell exiting? */
731 if (Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
732 hist_finish();
733 j_exit();
734 if (ep->flags & EF_FAKE_SIGDIE(1<<(2))) {
735 int sig = exstat - 128;
736
737 /* ham up our death a bit (at&t ksh
738 * only seems to do this for SIGTERM)
739 * Don't do it for SIGQUIT, since we'd
740 * dump a core..
741 */
742 if ((sig == SIGINT2 || sig == SIGTERM15) &&
743 getpgrp() == kshpid) {
744 setsig(&sigtraps[sig], SIG_DFL(void (*)(int))0,
745 SS_RESTORE_CURR0|SS_FORCE(1<<(3)));
746 kill(0, sig);
747 }
748 }
749 }
750 if (shf)
751 shf_close(shf);
752 reclaim();
753 exit(exstat);
754 }
755 if (shf)
756 shf_close(shf);
757 reclaim();
758
759 genv = genv->oenv;
760 afree(ep, ATEMP&genv->area);
761}
762
763/* Called after a fork to cleanup stuff left over from parents environment */
764void
765cleanup_parents_env(void)
766{
767 struct env *ep;
768 int fd;
769
770 /* Don't clean up temporary files - parent will probably need them.
771 * Also, can't easily reclaim memory since variables, etc. could be
772 * anywhere.
773 */
774
775 /* close all file descriptors hiding in savefd */
776 for (ep = genv; ep; ep = ep->oenv) {
1
Assuming pointer value is null
→
2
←
Loop condition is false. Execution continues on line 785
→
777 if (ep->savefd) {
778 for (fd = 0; fd < NUFILE32; fd++)
779 if (ep->savefd[fd] > 0)
780 close(ep->savefd[fd]);
781 afree(ep->savefd, &ep->area);
782 ep->savefd = NULL((void*)0);
783 }
784 }
785 genv->oenv = NULL((void*)0);
3
←
Access to field 'oenv' results in a dereference of a null pointer (loaded from variable 'genv')
786}
787
788/* Called just before an execve cleanup stuff temporary files */
789void
790cleanup_proc_env(void)
791{
792 struct env *ep;
793
794 for (ep = genv; ep; ep = ep->oenv)
795 remove_temps(ep->temps);
796}
797
798/* remove temp files and free ATEMP Area */
799static void
800reclaim(void)
801{
802 remove_temps(genv->temps);
803 genv->temps = NULL((void*)0);
804 afreeall(&genv->area);
805}
806
807static void
808remove_temps(struct temp *tp)
809{
810
811 for (; tp != NULL((void*)0); tp = tp->next)
812 if (tp->pid == procpid) {
813 unlink(tp->name);
814 }
815}
816
817/* Returns true if name refers to a restricted shell */
818static int
819is_restricted(char *name)
820{
821 char *p;
822
823 if ((p = strrchr(name, '/')))
824 name = p + 1;
825 /* accepts rsh, rksh, rpdksh, pdrksh */
826 if (strcmp(name, "rsh") && \
827 strcmp(name, "rksh") && \
828 strcmp(name, "rpdksh") && \
829 strcmp(name, "pdrksh"))
830 return(0);
831 else
832 return(1);
833
834}