Bug Summary

File:src/bin/stty/cchar.c
Warning:line 112, column 6
Dereference of null pointer (loaded from variable 'arg')

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 cchar.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/stty/obj -resource-dir /usr/local/lib/clang/13.0.0 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/bin/stty/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/stty/cchar.c
1/* $OpenBSD: cchar.c,v 1.12 2016/03/23 14:52:42 mmcc Exp $ */
2/* $NetBSD: cchar.c,v 1.10 1996/05/07 18:20:05 jtc Exp $ */
3
4/*-
5 * Copyright (c) 1991, 1993, 1994
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/types.h>
34#include <sys/ioctl.h>
35
36#include <err.h>
37#include <limits.h>
38#include <stddef.h>
39#include <stdlib.h>
40#include <string.h>
41#include <termios.h>
42
43#include "stty.h"
44#include "extern.h"
45
46/*
47 * Special control characters.
48 *
49 * Cchars1 are the standard names, cchars2 are the old aliases.
50 * The first are displayed, but both are recognized on the
51 * command line.
52 */
53const struct cchar cchars1[] = {
54 { "discard", VDISCARD15, CDISCARD('o'&037) },
55 { "dsusp", VDSUSP11, CDSUSP('y'&037) },
56 { "eof", VEOF0, CEOF('d'&037) },
57 { "eol", VEOL1, CEOL((unsigned char)'\377') },
58 { "eol2", VEOL22, CEOL((unsigned char)'\377') },
59 { "erase", VERASE3, CERASE0177 },
60 { "intr", VINTR8, CINTR('c'&037) },
61 { "kill", VKILL5, CKILL('u'&037) },
62 { "lnext", VLNEXT14, CLNEXT('v'&037) },
63 { "min", VMIN16, CMIN1 },
64 { "quit", VQUIT9, CQUIT034 },
65 { "reprint", VREPRINT6, CREPRINT('r'&037) },
66 { "start", VSTART12, CSTART('q'&037) },
67 { "status", VSTATUS18, CSTATUS((unsigned char)'\377') },
68 { "stop", VSTOP13, CSTOP('s'&037) },
69 { "susp", VSUSP10, CSUSP('z'&037) },
70 { "time", VTIME17, CTIME0 },
71 { "werase", VWERASE4, CWERASE('w'&037) },
72 { NULL((void*)0) },
73};
74
75const struct cchar cchars2[] = {
76 { "brk", VEOL1, CEOL((unsigned char)'\377') },
77 { "flush", VDISCARD15, CDISCARD('o'&037) },
78 { "rprnt", VREPRINT6, CREPRINT('r'&037) },
79 { NULL((void*)0) },
80};
81
82static int
83c_cchar(const void *a, const void *b)
84{
85 return (strcmp(((struct cchar *)a)->name, ((struct cchar *)b)->name));
86}
87
88int
89csearch(char ***argvp, struct info *ip)
90{
91 struct cchar *cp, tmp;
92 long val;
93 char *arg, *ep, *name;
94
95 name = **argvp;
96
97 tmp.name = name;
98 if (!(cp = (struct cchar *)bsearch(&tmp, cchars1,
1
Assuming 'cp' is non-null
→
99 sizeof(cchars1)/sizeof(struct cchar) - 1, sizeof(struct cchar),
100 c_cchar)) && !(cp = (struct cchar *)bsearch(&tmp, cchars2,
101 sizeof(cchars2)/sizeof(struct cchar) - 1, sizeof(struct cchar),
102 c_cchar)))
103 return (0);
104
105 arg = *++*argvp;
2
←
Value assigned to 'arg'
→
106 if (!arg) {
3
←
Assuming 'arg' is null
→
4
←
Taking true branch
→
107 warnx("option requires an argument -- %s", name);
108 usage();
109 }
110
111#define CHK(s)(*arg == s[0] && !strcmp(arg, s)) (*arg == s[0] && !strcmp(arg, s))
112 if (CHK("undef")(*arg == "undef"[0] && !strcmp(arg, "undef")) || CHK("<undef>")(*arg == "<undef>"[0] && !strcmp(arg, "<undef>"
)))
5
←
Dereference of null pointer (loaded from variable 'arg')
113 ip->t.c_cc[cp->sub] = _POSIX_VDISABLE(0377);
114 else if (cp->sub == VMIN16 || cp->sub == VTIME17) {
115 val = strtol(arg, &ep, 10);
116 if (val > UCHAR_MAX(127*2 +1) || val < 0) {
117 warnx("maximum option value is %d -- %s",
118 UCHAR_MAX(127*2 +1), name);
119 usage();
120 }
121 if (*ep != '\0') {
122 warnx("option requires a numeric argument -- %s", name);
123 usage();
124 }
125 ip->t.c_cc[cp->sub] = val;
126 } else if (arg[0] == '^')
127 ip->t.c_cc[cp->sub] = (arg[1] == '?') ? 0177 :
128 (arg[1] == '-') ? _POSIX_VDISABLE(0377) : arg[1] & 037;
129 else
130 ip->t.c_cc[cp->sub] = arg[0];
131 ip->set = 1;
132 return (1);
133}