/usr/src/usr.bin/vi/build/../ex/ex_init.c

Bug Summary

File:	src/usr.bin/vi/build/../ex/ex_init.c
Warning:	line 224, column 19 The right operand of '!=' is a garbage value

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ex_init.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/usr.bin/vi/build/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/usr.bin/vi/build -I /usr/src/usr.bin/vi/build/../include -I . -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/vi/build/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/usr.bin/vi/build/../ex/ex_init.c

1/*	$OpenBSD: ex_init.c,v 1.19 2021/10/24 21:24:17 deraadt Exp $	*/

3/*-
* Copyright (c) 1992, 1993, 1994
*	The Regents of the University of California.  All rights reserved.
* Copyright (c) 1992, 1993, 1994, 1995, 1996
*	Keith Bostic.  All rights reserved.
*
* See the LICENSE file for redistribution information.
*/

12#include "config.h"

14#include <sys/queue.h>
15#include <sys/stat.h>

17#include <bitstring.h>
18#include <errno(*__errno()).h>
19#include <fcntl.h>
20#include <limits.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <unistd.h>

26#include "../common/common.h"
27#include "tag.h"
28#include "pathnames.h"

30enum rc { NOEXIST, NOPERM, RCOK };
31static enum rc	exrc_isok(SCR *, struct stat *, int *, char *, int, int);

33static int ex_run_file(SCR *, int, char *);

35/*
* ex_screen_copy --
*	Copy ex screen.
*
* PUBLIC: int ex_screen_copy(SCR *, SCR *);
*/
41int
42ex_screen_copy(SCR *orig, SCR *sp)
43{
EX_PRIVATE *oexp, *nexp;

/* Create the private ex structure. */
CALLOC_RET(orig, nexp, 1, sizeof(EX_PRIVATE)){ if (((nexp) = calloc((1), (sizeof(EX_PRIVATE)))) == ((void *
)0)) { msgq((orig), M_SYSERR, ((void *)0)); return (1); } };
sp->ex_private = nexp;

/* Initialize queues. */
TAILQ_INIT(&nexp->tq)do { (&nexp->tq)->tqh_first = ((void *)0); (&nexp
->tq)->tqh_last = &(&nexp->tq)->tqh_first
; } while (0);
TAILQ_INIT(&nexp->tagfq)do { (&nexp->tagfq)->tqh_first = ((void *)0); (&
nexp->tagfq)->tqh_last = &(&nexp->tagfq)->
tqh_first; } while (0);

if (orig == NULL((void *)0)) {
} else {
oexp = EXP(orig)((EX_PRIVATE *)((orig)->ex_private));

if (oexp->lastbcomm != NULL((void *)0) &&
    (nexp->lastbcomm = strdup(oexp->lastbcomm)) == NULL((void *)0)) {
	msgq(sp, M_SYSERR, NULL((void *)0));
	return(1);
}
if (ex_tag_copy(orig, sp))
	return (1);
}
return (0);
67}

69/*
* ex_screen_end --
*	End a vi screen.
*
* PUBLIC: int ex_screen_end(SCR *);
*/
75int
76ex_screen_end(SCR *sp)
77{
EX_PRIVATE *exp;
int rval;

if ((exp = EXP(sp)((EX_PRIVATE *)((sp)->ex_private))) == NULL((void *)0))
return (0);

rval = 0;

/* Close down script connections. */
if (F_ISSET(sp, SC_SCRIPT)(((sp)->flags) & ((0x01000000))) && sscr_end(sp))
rval = 1;

if (argv_free(sp))
rval = 1;

free(exp->ibp);
free(exp->lastbcomm);

if (ex_tag_free(sp))
rval = 1;

/* Free private memory. */
free(exp);
sp->ex_private = NULL((void *)0);

return (rval);
104}

106/*
* ex_optchange --
*	Handle change of options for ex.
*
* PUBLIC: int ex_optchange(SCR *, int, char *, u_long *);
*/
112int
113ex_optchange(SCR *sp, int offset, char *str, u_long *valp)
114{
switch (offset) {
case O_TAGS:
return (ex_tagf_alloc(sp, str));
}
return (0);
120}

122/*
* ex_exrc --
*	Read the EXINIT environment variable and the startup exrc files,
*	and execute their commands.
*
* PUBLIC: int ex_exrc(SCR *);
*/
129int
130ex_exrc(SCR *sp)
131{
struct stat hsb, lsb;
char *p, path[PATH_MAX1024];
int fd;

/*
* Source the system, environment, $HOME and local .exrc values.
* Vi historically didn't check $HOME/.exrc if the environment
* variable EXINIT was set.  This is all done before the file is
* read in, because things in the .exrc information can set, for
* example, the recovery directory.
*
* !!!
* While nvi can handle any of the options settings of historic vi,
* the converse is not true.  Since users are going to have to have
* files and environmental variables that work with both, we use nvi
* versions of both the $HOME and local startup files if they exist,
* otherwise the historic ones.
*
* !!!
* For a discussion of permissions and when what .exrc files are
* read, see the comment above the exrc_isok() function below.
*
* !!!
* If the user started the historic of vi in $HOME, vi read the user's
* .exrc file twice, as $HOME/.exrc and as ./.exrc.  We avoid this, as
* it's going to make some commands behave oddly, and I can't imagine
* anyone depending on it.
*/
switch (exrc_isok(sp, &hsb, &fd, _PATH_SYSEXRC"/etc/vi.exrc", 1, 0)) {
1
Calling 'exrc_isok'→
8
←
Returning from 'exrc_isok'→
9
←
Control jumps to 'case NOEXIST:'  at line 161→
case NOEXIST:
case NOPERM:
break;
10
←
 Execution continues on line 171→
case RCOK:
if (ex_run_file(sp, fd, _PATH_SYSEXRC"/etc/vi.exrc"))
	return (1);
break;
}

/* Run the commands. */
if (EXCMD_RUNNING(sp->gp)(((&(sp->gp)->ecq)->lh_first)->clen != 0))
11
←
Assuming field 'clen' is equal to 0→
12
←
Taking false branch→
(void)ex_cmd(sp);
if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE)(((sp)->flags) & ((0x00000200 | 0x00000400))))
13
←
Assuming the condition is false→
14
←
Taking false branch→
return (0);

if ((p = getenv("NEXINIT")) != NULL((void *)0)) {
15
←
Assuming the condition is false→
16
←
Taking false branch→
if (ex_run_str(sp, "NEXINIT", p, strlen(p), 1, 0))
	return (1);
} else if ((p = getenv("EXINIT")) != NULL((void *)0)) {
17
←
Assuming the condition is false→
18
←
Taking false branch→
if (ex_run_str(sp, "EXINIT", p, strlen(p), 1, 0))
	return (1);
} else if ((p = getenv("HOME")) != NULL((void *)0) && *p) {
19
←
Assuming the condition is false→
(void)snprintf(path, sizeof(path), "%s/%s", p, _PATH_NEXRC".nexrc");
switch (exrc_isok(sp, &hsb, &fd, path, 0, 1)) {
case NOEXIST:
	(void)snprintf(path,
	    sizeof(path), "%s/%s", p, _PATH_EXRC".exrc");
	if (exrc_isok(sp, &hsb, &fd, path, 0, 1) == RCOK &&
	    ex_run_file(sp, fd, path))
		return (1);
	break;
case NOPERM:
	break;
case RCOK:
	if (ex_run_file(sp, fd, path))
		return (1);
	break;
}
}

/* Run the commands. */
if (EXCMD_RUNNING(sp->gp)(((&(sp->gp)->ecq)->lh_first)->clen != 0))
20
←
Taking false branch→
(void)ex_cmd(sp);
if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE)(((sp)->flags) & ((0x00000200 | 0x00000400))))
21
←
Taking false branch→
return (0);

/* Previous commands may have set the exrc option. */
if (O_ISSET(sp, O_EXRC)((((&(((sp)))->opts[(((O_EXRC)))])->flags) & ((
0x01))) ? (((sp)))->gp->opts[(((sp)))->opts[(((O_EXRC
)))].o_cur.val].o_cur.val : (((sp)))->opts[(((O_EXRC)))].o_cur
.val)) {
22
←
Assuming the condition is false→
23
←
'?' condition is false→
24
←
Assuming the condition is true→
25
←
Taking true branch→
switch (exrc_isok(sp, &lsb, &fd, _PATH_NEXRC".nexrc", 0, 0)) {
26
←
Control jumps to 'case RCOK:'  at line 223→
case NOEXIST:
	if (exrc_isok(sp, &lsb, &fd, _PATH_EXRC".exrc", 0, 0)
	    == RCOK) {
		if (lsb.st_dev != hsb.st_dev ||
		    lsb.st_ino != hsb.st_ino) {
			if (ex_run_file(sp, fd, _PATH_EXRC".exrc"))
				return (1);
		} else
			close(fd);
	}
	break;
case NOPERM:
	break;
case RCOK:
	if (lsb.st_dev != hsb.st_dev ||
27
←
The right operand of '!=' is a garbage value
	    lsb.st_ino != hsb.st_ino) {
		if (ex_run_file(sp, fd, _PATH_NEXRC".nexrc"))
			return (1);
	} else
		close(fd);
	break;
}
/* Run the commands. */
if (EXCMD_RUNNING(sp->gp)(((&(sp->gp)->ecq)->lh_first)->clen != 0))
	(void)ex_cmd(sp);
if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE)(((sp)->flags) & ((0x00000200 | 0x00000400))))
	return (0);
}

return (0);
240}

242/*
* ex_run_file --
*	Set up a file of ex commands to run.
*/
246static int
247ex_run_file(SCR *sp, int fd, char *name)
248{
ARGS *ap[2], a;
EXCMD cmd;

ex_cinit(&cmd, C_SOURCE, 0, OOBLNO0, OOBLNO0, 0, ap);
ex_cadd(&cmd, &a, name, strlen(name));
return (ex_sourcefd(sp, &cmd, fd));
255}

257/*
* ex_run_str --
*	Set up a string of ex commands to run.
*
* PUBLIC: int ex_run_str(SCR *, char *, char *, size_t, int, int);
*/
263int
264ex_run_str(SCR *sp, char *name, char *str, size_t len, int ex_flags,
  int nocopy)
266{
GS *gp;
EXCMD *ecp;

gp = sp->gp;
if (EXCMD_RUNNING(gp)(((&(gp)->ecq)->lh_first)->clen != 0)) {
CALLOC_RET(sp, ecp, 1, sizeof(EXCMD)){ if (((ecp) = calloc((1), (sizeof(EXCMD)))) == ((void *)0)) {
 msgq((sp), M_SYSERR, ((void *)0)); return (1); } };
LIST_INSERT_HEAD(&gp->ecq, ecp, q)do { if (((ecp)->q.le_next = (&gp->ecq)->lh_first
) != ((void *)0)) (&gp->ecq)->lh_first->q.le_prev
 = &(ecp)->q.le_next; (&gp->ecq)->lh_first =
 (ecp); (ecp)->q.le_prev = &(&gp->ecq)->lh_first
; } while (0);
} else
ecp = &gp->excmd;

F_INIT(ecp,((ecp)->flags) = ((ex_flags ? 0x00000800 | 0x00002000 | 0x00004000
 | 0x00020000 : 0))
   ex_flags ? E_BLIGNORE | E_NOAUTO | E_NOPRDEF | E_VLITONLY : 0)((ecp)->flags) = ((ex_flags ? 0x00000800 | 0x00002000 | 0x00004000
 | 0x00020000 : 0));

if (nocopy)
ecp->cp = str;
else
if ((ecp->cp = v_strdup(sp, str, len)) == NULL((void *)0))
	return (1);
ecp->clen = len;

if (name == NULL((void *)0))
ecp->if_name = NULL((void *)0);
else {
if ((ecp->if_name = v_strdup(sp, name, strlen(name))) == NULL((void *)0))
	return (1);
ecp->if_lno = 1;
F_SET(ecp, E_NAMEDISCARD)(((ecp)->flags) |= ((0x00001000)));
}

return (0);
297}

299/*
* exrc_isok --
*	Open and check a .exrc file for source-ability.
*
* !!!
* Historically, vi read the $HOME and local .exrc files if they were owned
* by the user's real ID, or the "sourceany" option was set, regardless of
* any other considerations.  We no longer support the sourceany option as
* it's a security problem of mammoth proportions.  We require the system
* .exrc file to be owned by root, the $HOME .exrc file to be owned by the
* user's effective ID (or that the user's effective ID be root) and the
* local .exrc files to be owned by the user's effective ID.  In all cases,
* the file cannot be writeable by anyone other than its owner.
*
* In O'Reilly ("Learning the VI Editor", Fifth Ed., May 1992, page 106),
* it notes that System V release 3.2 and later has an option "[no]exrc".
* The behavior is that local .exrc files are read only if the exrc option
* is set.  The default for the exrc option was off, so, by default, local
* .exrc files were not read.  The problem this was intended to solve was
* that System V permitted users to give away files, so there's no possible
* ownership or writeability test to ensure that the file is safe.
*
* POSIX 1003.2-1992 standardized exrc as an option.  It required the exrc
* option to be off by default, thus local .exrc files are not to be read
* by default.  The Rationale noted (incorrectly) that this was a change
* to historic practice, but correctly noted that a default of off improves
* system security.  POSIX also required that vi check the effective user
* ID instead of the real user ID, which is why we've switched from historic
* practice.
*
* We initialize the exrc variable to off.  If it's turned on by the system
* or $HOME .exrc files, and the local .exrc file passes the ownership and
* writeability tests, then we read it.  This breaks historic 4BSD practice,
* but it gives us a measure of security on systems where users can give away
* files.
*/
335static enum rc
336exrc_isok(SCR *sp, struct stat *sbp, int *fdp, char *path, int rootown,
  int rootid)
338{
enum { ROOTOWN, OWN, WRITER } etype;
uid_t euid;
int nf1, nf2;
char *a, *b, buf[PATH_MAX1024];

if ((*fdp = open(path, O_RDONLY0x0000)) < 0) {
2
←
Assuming the condition is true→
3
←
Taking true branch→
if (errno(*__errno()) == ENOENT2)
4
←
Assuming the condition is true→
5
←
Taking true branch→
                      /* This is the only case where ex_exrc()
                       * should silently try the next file, for
                       * example .exrc after .nexrc.
	 */
	return (NOEXIST);
6
←
Returning without writing to 'sbp->st_dev'→
7
←
Returning zero, which participates in a condition later→

msgq_str(sp, M_SYSERR, path, "%s");
return (NOPERM);
}

if (fstat(*fdp, sbp)) {
msgq_str(sp, M_SYSERR, path, "%s");
close(*fdp);
return (NOPERM);
}

/* Check ownership permissions. */
euid = geteuid();
if (!(rootown && sbp->st_uid == 0) &&
   !(rootid && euid == 0) && sbp->st_uid != euid) {
etype = rootown ? ROOTOWN : OWN;
goto denied;
}

/* Check writeability. */
if (sbp->st_mode & (S_IWGRP0000020 | S_IWOTH0000002)) {
etype = WRITER;
goto denied;
}
return (RCOK);

377denied:	a = msg_print(sp, path, &nf1);
if (strchr(path, '/') == NULL((void *)0) && getcwd(buf, sizeof(buf)) != NULL((void *)0)) {
b = msg_print(sp, buf, &nf2);
switch (etype) {
case ROOTOWN:
	msgq(sp, M_ERR,
	    "%s/%s: not sourced: not owned by you or root",
	    b, a);
	break;
case OWN:
	msgq(sp, M_ERR,
	    "%s/%s: not sourced: not owned by you", b, a);
	break;
case WRITER:
	msgq(sp, M_ERR,
  "%s/%s: not sourced: writable by a user other than the owner", b, a);
	break;
}
if (nf2)
	FREE_SPACE(sp, b, 0){ GS *L__gp = (sp) == ((void *)0) ? ((void *)0) : (sp)->gp
; if (L__gp != ((void *)0) && (b) == L__gp->tmp_bp
) (((L__gp)->flags) &= ~((0x0100))); else free(b); };
} else
switch (etype) {
case ROOTOWN:
	msgq(sp, M_ERR,
	    "%s: not sourced: not owned by you or root", a);
	break;
case OWN:
	msgq(sp, M_ERR,
	    "%s: not sourced: not owned by you", a);
	break;
case WRITER:
	msgq(sp, M_ERR,
   "%s: not sourced: writable by a user other than the owner", a);
	break;
}

if (nf1)
FREE_SPACE(sp, a, 0){ GS *L__gp = (sp) == ((void *)0) ? ((void *)0) : (sp)->gp
; if (L__gp != ((void *)0) && (a) == L__gp->tmp_bp
) (((L__gp)->flags) &= ~((0x0100))); else free(a); };
close(*fdp);
return (NOPERM);
417}