Bug Summary

File:src/bin/ksh/main.c
Warning:line 799, column 13
Access to field 'oenv' results in a dereference of a null pointer (loaded from variable 'genv')

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name main.c -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 -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -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/llvm16/lib/clang/16 -D EMACS -D VI -I . -I /usr/src/bin/ksh -I /usr/src/bin/ksh/../../lib/libc/gen -internal-isystem /usr/local/llvm16/lib/clang/16/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/bin/ksh/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fno-jump-tables -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/scan/2024-01-11-140451-98009-1 -x c /usr/src/bin/ksh/main.c
1/* $OpenBSD: main.c,v 1.100 2023/07/23 23:42:03 kn 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=#? } ${PS4=+ }";
82
83static const char *initcoms [] = {
84#ifndef SMALL
85 "typeset", "-r", "KSH_VERSION", NULL((void *)0),
86#endif /* SMALL */
87 "typeset", "-x", "SHELL", "PATH", "HOME", "PWD", "OLDPWD", NULL((void *)0),
88 "typeset", "-ir", "PPID", NULL((void *)0),
89 "typeset", "-i", "OPTIND=1", NULL((void *)0),
90#ifndef SMALL
91 "eval", "typeset -i RANDOM MAILCHECK=\"${MAILCHECK-600}\" SECONDS=\"${SECONDS-0}\" TMOUT=\"${TMOUT-0}\"", NULL((void *)0),
92#else
93 "eval", "typeset -i RANDOM SECONDS=\"${SECONDS-0}\" TMOUT=\"${TMOUT-0}\"", NULL((void *)0),
94#endif /* SMALL */
95 "alias",
96 /* Standard ksh aliases */
97 "hash=alias -t", /* not "alias -t --": hash -r needs to work */
98 "stop=kill -STOP",
99 "autoload=typeset -fu",
100 "functions=typeset -f",
101 "history=fc -l",
102 "integer=typeset -i",
103 "nohup=nohup ",
104 "local=typeset",
105 "r=fc -s",
106 /* Aliases that are builtin commands in at&t */
107 "login=exec login",
108 NULL((void *)0),
109 /* this is what at&t ksh seems to track, with the addition of emacs */
110 "alias", "-tU",
111 "cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
112 "mail", "make", "mv", "pr", "rm", "sed", "sh", "vi", "who",
113 NULL((void *)0),
114 NULL((void *)0)
115};
116
117char username[_PW_NAME_LEN31 + 1];
118
119#ifndef SMALL
120#define version_param(initcoms[2]) (initcoms[2])
121#endif /* SMALL */
122
123/* The shell uses its own variation on argv, to build variables like
124 * $0 and $@.
125 * Allocate a new array since modifying the original argv will modify
126 * ps output.
127 */
128static char **
129make_argv(int argc, char *argv[])
130{
131 int i;
132 char **nargv;
133
134 nargv = areallocarray(NULL((void *)0), argc + 1, sizeof(char *), &aperm);
135 nargv[0] = (char *) kshname;
136 for (i = 1; i < argc; i++)
137 nargv[i] = argv[i];
138 nargv[i] = NULL((void *)0);
139
140 return nargv;
141}
142
143int
144main(int argc, char *argv[])
145{
146 int i;
147 int argi;
148 Source *s;
149 struct block *l;
150 int restricted, errexit;
151 char **wp;
152 struct env env;
153 pid_t ppid;
154
155 kshname = argv[0];
156
157 if (issetugid()) { /* could later drop privileges */
158 if (pledge("stdio rpath wpath cpath fattr flock getpw proc "
159 "exec tty id", NULL((void *)0)) == -1) {
160 perror("pledge");
161 exit(1);
162 }
163 } else {
164 if (pledge("stdio rpath wpath cpath fattr flock getpw proc "
165 "exec tty", NULL((void *)0)) == -1) {
166 perror("pledge");
167 exit(1);
168 }
169 }
170
171 ainit(&aperm); /* initialize permanent Area */
172
173 /* set up base environment */
174 memset(&env, 0, sizeof(env));
175 env.type = E_NONE0;
176 ainit(&env.area);
177 genv = &env;
178 newblock(); /* set up global l->vars and l->funs */
179
180 /* Do this first so output routines (eg, errorf, shellf) can work */
181 initio();
182
183 initvar();
184
185 initctypes();
186
187 inittraps();
188
189 coproc_init();
190
191 /* set up variable and command dictionaries */
192 ktinit(&taliases, APERM&aperm, 0);
193 ktinit(&aliases, APERM&aperm, 0);
194 ktinit(&homedirs, APERM&aperm, 0);
195
196 /* define shell keywords */
197 initkeywords();
198
199 /* define built-in commands */
200 ktinit(&builtins, APERM&aperm, 64); /* must be 2^n (currently 40 builtins) */
201 for (i = 0; shbuiltins[i].name != NULL((void *)0); i++)
202 builtin(shbuiltins[i].name, shbuiltins[i].func);
203 for (i = 0; kshbuiltins[i].name != NULL((void *)0); i++)
204 builtin(kshbuiltins[i].name, kshbuiltins[i].func);
205
206 init_histvec();
207
208 def_path = _PATH_DEFPATH"/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin";
209 {
210 size_t len = confstr(_CS_PATH1, NULL((void *)0), 0);
211 char *new;
212
213 if (len > 0) {
214 confstr(_CS_PATH1, new = alloc(len + 1, APERM&aperm), len + 1);
215 def_path = new;
216 }
217 }
218
219 /* Set PATH to def_path (will set the path global variable).
220 * (import of environment below will probably change this setting).
221 */
222 {
223 struct tbl *vp = global("PATH");
224 /* setstr can't fail here */
225 setstr(vp, def_path, KSH_RETURN_ERROR0x1);
226 }
227
228
229 /* Turn on nohup by default for now - will change to off
230 * by default once people are aware of its existence
231 * (at&t ksh does not have a nohup option - it always sends
232 * the hup).
233 */
234 Flag(FNOHUP)(shell_flags[(int) (FNOHUP)]) = 1;
235
236 /* Turn on brace expansion by default. At&t ksh's that have
237 * alternation always have it on. BUT, posix doesn't have
238 * brace expansion, so set this before setting up FPOSIX
239 * (change_flag() clears FBRACEEXPAND when FPOSIX is set).
240 */
241 Flag(FBRACEEXPAND)(shell_flags[(int) (FBRACEEXPAND)]) = 1;
242
243 /* set posix flag just before environment so that it will have
244 * exactly the same effect as the POSIXLY_CORRECT environment
245 * variable. If this needs to be done sooner to ensure correct posix
246 * operation, an initial scan of the environment will also have
247 * done sooner.
248 */
249#ifdef POSIXLY_CORRECT
250 change_flag(FPOSIX, OF_SPECIAL0x04, 1);
251#endif /* POSIXLY_CORRECT */
252
253 /* Check to see if we're /bin/sh. */
254 if (!strcmp(kshname, "sh") || !strcmp(kshname, "-sh") ||
255 (strlen(kshname) >= 3 &&
256 !strcmp(&kshname[strlen(kshname) - 3], "/sh"))) {
257 Flag(FSH)(shell_flags[(int) (FSH)]) = 1;
258#ifndef SMALL
259 version_param(initcoms[2]) = "SH_VERSION";
260#endif /* SMALL */
261 }
262
263 /* Set edit mode to emacs by default, may be overridden
264 * by the environment or the user. Also, we want tab completion
265 * on in vi by default. */
266#if defined(EMACS1)
267 change_flag(FEMACS, OF_SPECIAL0x04, 1);
268#endif /* EMACS */
269#if defined(VI1)
270 Flag(FVITABCOMPLETE)(shell_flags[(int) (FVITABCOMPLETE)]) = 1;
271#endif /* VI */
272
273 /* import environment */
274 if (environ != NULL((void *)0))
275 for (wp = environ; *wp != NULL((void *)0); wp++)
276 typeset(*wp, IMPORT(1<<(21))|EXPORT(1<<(3)), 0, 0, 0);
277
278 kshpid = procpid = getpid();
279 typeset(initifs, 0, 0, 0, 0); /* for security */
280
281 /* assign default shell variable values */
282 substitute(initsubs, 0);
283
284 /* Figure out the current working directory and set $PWD */
285 {
286 struct stat s_pwd, s_dot;
287 struct tbl *pwd_v = global("PWD");
288 char *pwd = str_val(pwd_v);
289 char *pwdx = pwd;
290
291 /* Try to use existing $PWD if it is valid */
292 if (pwd[0] != '/' ||
293 stat(pwd, &s_pwd) == -1 || stat(".", &s_dot) == -1 ||
294 s_pwd.st_dev != s_dot.st_dev ||
295 s_pwd.st_ino != s_dot.st_ino)
296 pwdx = NULL((void *)0);
297 set_current_wd(pwdx);
298 if (current_wd[0])
299 simplify_path(current_wd);
300 /* Only set pwd if we know where we are or if it had a
301 * bogus value
302 */
303 if (current_wd[0] || pwd != null)
304 /* setstr can't fail here */
305 setstr(pwd_v, current_wd, KSH_RETURN_ERROR0x1);
306 }
307 ppid = getppid();
308 setint(global("PPID"), (int64_t) ppid);
309#ifndef SMALL
310 /* setstr can't fail here */
311 setstr(global(version_param(initcoms[2])), ksh_version, KSH_RETURN_ERROR0x1);
312#endif /* SMALL */
313
314 /* execute initialization statements */
315 for (wp = (char**) initcoms; *wp != NULL((void *)0); wp++) {
316 shcomexec(wp);
317 for (; *wp != NULL((void *)0); wp++)
318 ;
319 }
320
321
322 ksheuid = geteuid();
323 init_username();
324 safe_prompt = ksheuid ? "$ " : "# ";
325 {
326 struct tbl *vp = global("PS1");
327
328 /* Set PS1 if it isn't set */
329 if (!(vp->flag & ISSET(1<<(2)))) {
330 /* setstr can't fail here */
331 setstr(vp, "\\h\\$ ", KSH_RETURN_ERROR0x1);
332 }
333 }
334
335 /* Set this before parsing arguments */
336 Flag(FPRIVILEGED)(shell_flags[(int) (FPRIVILEGED)]) = getuid() != ksheuid || getgid() != getegid();
337
338 /* this to note if monitor is set on command line (see below) */
339 Flag(FMONITOR)(shell_flags[(int) (FMONITOR)]) = 127;
340 argi = parse_args(argv, OF_CMDLINE0x01, NULL((void *)0));
341 if (argi < 0)
342 exit(1);
343
344 if (Flag(FCOMMAND)(shell_flags[(int) (FCOMMAND)])) {
345 s = pushs(SSTRING3, ATEMP&genv->area);
346 if (!(s->start = s->str = argv[argi++]))
347 errorf("-c requires an argument");
348 if (argv[argi])
349 kshname = argv[argi++];
350 } else if (argi < argc && !Flag(FSTDIN)(shell_flags[(int) (FSTDIN)])) {
351 s = pushs(SFILE1, ATEMP&genv->area);
352 s->file = argv[argi++];
353 s->u.shf = shf_open(s->file, O_RDONLY0x0000, 0, SHF_MAPHI0x0020|SHF_CLEXEC0x0010);
354 if (s->u.shf == NULL((void *)0)) {
355 exstat = 127; /* POSIX */
356 errorf("%s: %s", s->file, strerror(errno(*__errno())));
357 }
358 kshname = s->file;
359 } else {
360 Flag(FSTDIN)(shell_flags[(int) (FSTDIN)]) = 1;
361 s = pushs(SSTDIN2, ATEMP&genv->area);
362 s->file = "<stdin>";
363 s->u.shf = shf_fdopen(0, SHF_RD0x0001 | can_seek(0), NULL((void *)0));
364 if (isatty(0) && isatty(2)) {
365 Flag(FTALKING)(shell_flags[(int) (FTALKING)]) = Flag(FTALKING_I)(shell_flags[(int) (FTALKING_I)]) = 1;
366 /* The following only if isatty(0) */
367 s->flags |= SF_TTY(1<<(3));
368 s->u.shf->flags |= SHF_INTERRUPT0x0080;
369 s->file = NULL((void *)0);
370 }
371 }
372
373 /* This bizarreness is mandated by POSIX */
374 {
375 struct stat s_stdin;
376
377 if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode)((s_stdin.st_mode & 0170000) == 0020000) &&
378 Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
379 reset_nonblock(0);
380 }
381
382 /* initialize job control */
383 i = Flag(FMONITOR)(shell_flags[(int) (FMONITOR)]) != 127;
384 Flag(FMONITOR)(shell_flags[(int) (FMONITOR)]) = 0;
385 j_init(i);
386 /* Do this after j_init(), as tty_fd is not initialized 'til then */
387 if (Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
388 x_init();
389
390 l = genv->loc;
391 l->argv = make_argv(argc - (argi - 1), &argv[argi - 1]);
392 l->argc = argc - argi;
393 getopts_reset(1);
394
395 /* Disable during .profile/ENV reading */
396 restricted = Flag(FRESTRICTED)(shell_flags[(int) (FRESTRICTED)]);
397 Flag(FRESTRICTED)(shell_flags[(int) (FRESTRICTED)]) = 0;
398 errexit = Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]);
399 Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) = 0;
400
401 /* Do this before profile/$ENV so that if it causes problems in them,
402 * user will know why things broke.
403 */
404 if (!current_wd[0] && Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
405 warningf(false0, "Cannot determine current working directory");
406
407 if (Flag(FLOGIN)(shell_flags[(int) (FLOGIN)])) {
408 include(KSH_SYSTEM_PROFILE"/etc/profile", 0, NULL((void *)0), 1);
409 if (!Flag(FPRIVILEGED)(shell_flags[(int) (FPRIVILEGED)]))
410 include(substitute("$HOME/.profile", 0), 0, NULL((void *)0), 1);
411 }
412
413 if (Flag(FPRIVILEGED)(shell_flags[(int) (FPRIVILEGED)]))
414 include("/etc/suid_profile", 0, NULL((void *)0), 1);
415 else if (Flag(FTALKING)(shell_flags[(int) (FTALKING)])) {
416 char *env_file;
417
418 /* include $ENV */
419 env_file = str_val(global("ENV"));
420
421#ifdef DEFAULT_ENV
422 /* If env isn't set, include default environment */
423 if (env_file == null)
424 env_file = DEFAULT_ENV;
425#endif /* DEFAULT_ENV */
426 env_file = substitute(env_file, DOTILDE(1<<(3)));
427 if (*env_file != '\0')
428 include(env_file, 0, NULL((void *)0), 1);
429 }
430
431 if (is_restricted(argv[0]) || is_restricted(str_val(global("SHELL"))))
432 restricted = 1;
433 if (restricted) {
434 static const char *const restr_com[] = {
435 "typeset", "-r", "PATH",
436 "ENV", "SHELL",
437 NULL((void *)0)
438 };
439 shcomexec((char **) restr_com);
440 /* After typeset command... */
441 Flag(FRESTRICTED)(shell_flags[(int) (FRESTRICTED)]) = 1;
442 }
443 if (errexit)
444 Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) = 1;
445
446 if (Flag(FTALKING)(shell_flags[(int) (FTALKING)])) {
447 hist_init(s);
448 alarm_init();
449 } else
450 Flag(FTRACKALL)(shell_flags[(int) (FTRACKALL)]) = 1; /* set after ENV */
451
452 shell(s, true1); /* doesn't return */
453 return 0;
454}
455
456static void
457init_username(void)
458{
459 char *p;
460 struct tbl *vp = global("USER");
461
462 if (vp->flag & ISSET(1<<(2)))
463 p = ksheuid == 0 ? "root" : str_val(vp);
464 else
465 p = getlogin();
466
467 strlcpy(username, p != NULL((void *)0) ? p : "?", sizeof username);
468}
469
470int
471include(const char *name, int argc, char **argv, int intr_ok)
472{
473 Source *volatile s = NULL((void *)0);
474 struct shf *shf;
475 char **volatile old_argv;
476 volatile int old_argc;
477 int i;
478
479 shf = shf_open(name, O_RDONLY0x0000, 0, SHF_MAPHI0x0020|SHF_CLEXEC0x0010);
480 if (shf == NULL((void *)0))
481 return -1;
482
483 if (argv) {
484 old_argv = genv->loc->argv;
485 old_argc = genv->loc->argc;
486 } else {
487 old_argv = NULL((void *)0);
488 old_argc = 0;
489 }
490 newenv(E_INCL3);
491 i = sigsetjmp(genv->jbuf, 0);
492 if (i) {
493 quitenv(s ? s->u.shf : NULL((void *)0));
494 if (old_argv) {
495 genv->loc->argv = old_argv;
496 genv->loc->argc = old_argc;
497 }
498 switch (i) {
499 case LRETURN1:
500 case LERROR3:
501 return exstat & 0xff; /* see below */
502 case LINTR5:
503 /* intr_ok is set if we are including .profile or $ENV.
504 * If user ^C's out, we don't want to kill the shell...
505 */
506 if (intr_ok && (exstat - 128) != SIGTERM15)
507 return 1;
508 /* FALLTHROUGH */
509 case LEXIT2:
510 case LLEAVE4:
511 case LSHELL8:
512 unwind(i);
513 /* NOTREACHED */
514 default:
515 internal_errorf("%s: %d", __func__, i);
516 /* NOTREACHED */
517 }
518 }
519 if (argv) {
520 genv->loc->argv = argv;
521 genv->loc->argc = argc;
522 }
523 s = pushs(SFILE1, ATEMP&genv->area);
524 s->u.shf = shf;
525 s->file = str_save(name, ATEMP&genv->area);
526 i = shell(s, false0);
527 quitenv(s->u.shf);
528 if (old_argv) {
529 genv->loc->argv = old_argv;
530 genv->loc->argc = old_argc;
531 }
532 return i & 0xff; /* & 0xff to ensure value not -1 */
533}
534
535/*
536 * spawn a command into a shell optionally keeping track of line
537 * number.
538 */
539int
540command(const char *comm, int line)
541{
542 Source *s;
543
544 s = pushs(SSTRING3, ATEMP&genv->area);
545 s->start = s->str = comm;
546 s->line = line;
547 return shell(s, false0);
548}
549
550/*
551 * run the commands from the input source, returning status.
552 */
553int
554shell(Source *volatile s, volatile int toplevel)
555{
556 struct op *t;
557 volatile int wastty = s->flags & SF_TTY(1<<(3));
558 volatile int attempts = 13;
559 volatile int interactive = Flag(FTALKING)(shell_flags[(int) (FTALKING)]) && toplevel;
560 Source *volatile old_source = source;
561 int i;
562
563 newenv(E_PARSE1);
564 if (interactive)
565 really_exit = 0;
566 i = sigsetjmp(genv->jbuf, 0);
567 if (i) {
568 switch (i) {
569 case LINTR5: /* we get here if SIGINT not caught or ignored */
570 case LERROR3:
571 case LSHELL8:
572 if (interactive) {
573 c_fc_reset();
574 if (i == LINTR5)
575 shellf("\n");
576 /* Reset any eof that was read as part of a
577 * multiline command.
578 */
579 if (Flag(FIGNOREEOF)(shell_flags[(int) (FIGNOREEOF)]) && s->type == SEOF0 &&
580 wastty)
581 s->type = SSTDIN2;
582 /* Used by exit command to get back to
583 * top level shell. Kind of strange since
584 * interactive is set if we are reading from
585 * a tty, but to have stopped jobs, one only
586 * needs FMONITOR set (not FTALKING/SF_TTY)...
587 */
588 /* toss any input we have so far */
589 s->start = s->str = null;
590 break;
591 }
592 /* FALLTHROUGH */
593 case LEXIT2:
594 case LLEAVE4:
595 case LRETURN1:
596 source = old_source;
597 quitenv(NULL((void *)0));
598 unwind(i); /* keep on going */
599 /* NOTREACHED */
600 default:
601 source = old_source;
602 quitenv(NULL((void *)0));
603 internal_errorf("%s: %d", __func__, i);
604 /* NOTREACHED */
605 }
606 }
607
608 while (1) {
609 if (trap)
610 runtraps(0);
611
612 if (s->next == NULL((void *)0)) {
613 if (Flag(FVERBOSE)(shell_flags[(int) (FVERBOSE)]))
614 s->flags |= SF_ECHO(1<<(0));
615 else
616 s->flags &= ~SF_ECHO(1<<(0));
617 }
618
619 if (interactive) {
620 got_sigwinch = 1;
621 j_notify();
622#ifndef SMALL
623 mcheck();
624#endif /* SMALL */
625 set_prompt(PS10);
626 }
627
628 t = compile(s);
629 if (t != NULL((void *)0) && t->type == TEOF0) {
630 if (wastty && Flag(FIGNOREEOF)(shell_flags[(int) (FIGNOREEOF)]) && --attempts > 0) {
631 shellf("Use `exit' to leave ksh\n");
632 s->type = SSTDIN2;
633 } else if (wastty && !really_exit &&
634 j_stopped_running()) {
635 really_exit = 1;
636 s->type = SSTDIN2;
637 } else {
638 /* this for POSIX, which says EXIT traps
639 * shall be taken in the environment
640 * immediately after the last command
641 * executed.
642 */
643 if (toplevel)
644 unwind(LEXIT2);
645 break;
646 }
647 }
648
649 if (t && (!Flag(FNOEXEC)(shell_flags[(int) (FNOEXEC)]) || (s->flags & SF_TTY(1<<(3)))))
650 exstat = execute(t, 0, NULL((void *)0));
651
652 if (t != NULL((void *)0) && t->type != TEOF0 && interactive && really_exit)
653 really_exit = 0;
654
655 reclaim();
656 }
657 quitenv(NULL((void *)0));
658 source = old_source;
659 return exstat;
660}
661
662/* return to closest error handler or shell(), exit if none found */
663void
664unwind(int i)
665{
666 /* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
667 if (i == LEXIT2 || (Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) && (i == LERROR3 || i == LINTR5) &&
668 sigtraps[SIGEXIT_0].trap)) {
669 if (trap)
670 runtraps(0);
671 runtrap(&sigtraps[SIGEXIT_0]);
672 i = LLEAVE4;
673 } else if (Flag(FERREXIT)(shell_flags[(int) (FERREXIT)]) && (i == LERROR3 || i == LINTR5)) {
674 if (trap)
675 runtraps(0);
676 runtrap(&sigtraps[SIGERR_33]);
677 i = LLEAVE4;
678 }
679 while (1) {
680 switch (genv->type) {
681 case E_PARSE1:
682 case E_FUNC2:
683 case E_INCL3:
684 case E_LOOP5:
685 case E_ERRH6:
686 siglongjmp(genv->jbuf, i);
687 /* NOTREACHED */
688
689 case E_NONE0:
690 if (i == LINTR5)
691 genv->flags |= EF_FAKE_SIGDIE(1<<(2));
692 /* FALLTHROUGH */
693
694 default:
695 quitenv(NULL((void *)0));
696 /*
697 * quitenv() may have reclaimed the memory
698 * used by source which will end badly when
699 * we jump to a function that expects it to
700 * be valid
701 */
702 source = NULL((void *)0);
703 }
704 }
705}
706
707void
708newenv(int type)
709{
710 struct env *ep;
711
712 ep = alloc(sizeof(*ep), ATEMP&genv->area);
713 ep->type = type;
714 ep->flags = 0;
715 ainit(&ep->area);
716 ep->loc = genv->loc;
717 ep->savefd = NULL((void *)0);
718 ep->oenv = genv;
719 ep->temps = NULL((void *)0);
720 genv = ep;
721}
722
723void
724quitenv(struct shf *shf)
725{
726 struct env *ep = genv;
727 int fd;
728
729 if (ep->oenv && ep->oenv->loc != ep->loc)
730 popblock();
731 if (ep->savefd != NULL((void *)0)) {
732 for (fd = 0; fd < NUFILE32; fd++)
733 /* if ep->savefd[fd] < 0, means fd was closed */
734 if (ep->savefd[fd])
735 restfd(fd, ep->savefd[fd]);
736 if (ep->savefd[2]) /* Clear any write errors */
737 shf_reopen(2, SHF_WR0x0002, shl_out(&shf_iob[2]));
738 }
739
740 /* Bottom of the stack.
741 * Either main shell is exiting or cleanup_parents_env() was called.
742 */
743 if (ep->oenv == NULL((void *)0)) {
744 if (ep->type == E_NONE0) { /* Main shell exiting? */
745 if (Flag(FTALKING)(shell_flags[(int) (FTALKING)]))
746 hist_finish();
747 j_exit();
748 if (ep->flags & EF_FAKE_SIGDIE(1<<(2))) {
749 int sig = exstat - 128;
750
751 /* ham up our death a bit (at&t ksh
752 * only seems to do this for SIGTERM)
753 * Don't do it for SIGQUIT, since we'd
754 * dump a core..
755 */
756 if ((sig == SIGINT2 || sig == SIGTERM15) &&
757 getpgrp() == kshpid) {
758 setsig(&sigtraps[sig], SIG_DFL(void (*)(int))0,
759 SS_RESTORE_CURR0|SS_FORCE(1<<(3)));
760 kill(0, sig);
761 }
762 }
763 }
764 if (shf)
765 shf_close(shf);
766 reclaim();
767 exit(exstat);
768 }
769 if (shf)
770 shf_close(shf);
771 reclaim();
772
773 genv = genv->oenv;
774 afree(ep, ATEMP&genv->area);
775}
776
777/* Called after a fork to cleanup stuff left over from parents environment */
778void
779cleanup_parents_env(void)
780{
781 struct env *ep;
782 int fd;
783
784 /* Don't clean up temporary files - parent will probably need them.
785 * Also, can't easily reclaim memory since variables, etc. could be
786 * anywhere.
787 */
788
789 /* close all file descriptors hiding in savefd */
790 for (ep = genv; ep; ep = ep->oenv) {
1
Assuming pointer value is null
→
2
←
Loop condition is false. Execution continues on line 799
→
791 if (ep->savefd) {
792 for (fd = 0; fd < NUFILE32; fd++)
793 if (ep->savefd[fd] > 0)
794 close(ep->savefd[fd]);
795 afree(ep->savefd, &ep->area);
796 ep->savefd = NULL((void *)0);
797 }
798 }
799 genv->oenv = NULL((void *)0);
3
←
Access to field 'oenv' results in a dereference of a null pointer (loaded from variable 'genv')
800}
801
802/* Called just before an execve cleanup stuff temporary files */
803void
804cleanup_proc_env(void)
805{
806 struct env *ep;
807
808 for (ep = genv; ep; ep = ep->oenv)
809 remove_temps(ep->temps);
810}
811
812/* remove temp files and free ATEMP Area */
813static void
814reclaim(void)
815{
816 remove_temps(genv->temps);
817 genv->temps = NULL((void *)0);
818 afreeall(&genv->area);
819}
820
821static void
822remove_temps(struct temp *tp)
823{
824
825 for (; tp != NULL((void *)0); tp = tp->next)
826 if (tp->pid == procpid) {
827 unlink(tp->name);
828 }
829}
830
831/* Returns true if name refers to a restricted shell */
832static int
833is_restricted(char *name)
834{
835 char *p;
836
837 if ((p = strrchr(name, '/')))
838 name = p + 1;
839 /* accepts rsh, rksh, rpdksh, pdrksh */
840 if (strcmp(name, "rsh") && \
841 strcmp(name, "rksh") && \
842 strcmp(name, "rpdksh") && \
843 strcmp(name, "pdrksh"))
844 return(0);
845 else
846 return(1);
847
848}