Bug Summary

File:src/usr.bin/diff/diff.c
Warning:line 297, column 6
Null pointer passed as 1st argument to string comparison function

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 diff.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/diff/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/usr.bin/diff/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/diff/diff.c
1/* $OpenBSD: diff.c,v 1.67 2019/06/28 13:35:00 deraadt Exp $ */
2
3/*
4 * Copyright (c) 2003 Todd C. Miller <millert@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 *
18 * Sponsored in part by the Defense Advanced Research Projects
19 * Agency (DARPA) and Air Force Research Laboratory, Air Force
20 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
21 */
22
23#include <sys/stat.h>
24
25#include <ctype.h>
26#include <err.h>
27#include <errno(*__errno()).h>
28#include <getopt.h>
29#include <stdlib.h>
30#include <stdio.h>
31#include <stdarg.h>
32#include <string.h>
33#include <unistd.h>
34#include <limits.h>
35
36#include "diff.h"
37#include "xmalloc.h"
38
39int Nflag, Pflag, rflag, sflag, Tflag;
40int diff_format, diff_context, status;
41char *start, *ifdefname, *diffargs, *label[2], *ignore_pats;
42struct stat stb1, stb2;
43struct excludes *excludes_list;
44regex_t ignore_re;
45
46#define OPTIONS"0123456789abC:cdD:efhI:iL:lnNPpqrS:sTtU:uwX:x:" "0123456789abC:cdD:efhI:iL:lnNPpqrS:sTtU:uwX:x:"
47static struct option longopts[] = {
48 { "text", no_argument0, 0, 'a' },
49 { "ignore-space-change", no_argument0, 0, 'b' },
50 { "context", optional_argument2, 0, 'C' },
51 { "ifdef", required_argument1, 0, 'D' },
52 { "minimal", no_argument0, 0, 'd' },
53 { "ed", no_argument0, 0, 'e' },
54 { "forward-ed", no_argument0, 0, 'f' },
55 { "ignore-matching-lines", required_argument1, 0, 'I' },
56 { "ignore-case", no_argument0, 0, 'i' },
57 { "label", required_argument1, 0, 'L' },
58 { "new-file", no_argument0, 0, 'N' },
59 { "rcs", no_argument0, 0, 'n' },
60 { "unidirectional-new-file", no_argument0, 0, 'P' },
61 { "show-c-function", no_argument0, 0, 'p' },
62 { "brief", no_argument0, 0, 'q' },
63 { "recursive", no_argument0, 0, 'r' },
64 { "report-identical-files", no_argument0, 0, 's' },
65 { "starting-file", required_argument1, 0, 'S' },
66 { "expand-tabs", no_argument0, 0, 't' },
67 { "initial-tab", no_argument0, 0, 'T' },
68 { "unified", optional_argument2, 0, 'U' },
69 { "ignore-all-space", no_argument0, 0, 'w' },
70 { "exclude", required_argument1, 0, 'x' },
71 { "exclude-from", required_argument1, 0, 'X' },
72 { NULL((void *)0), 0, 0, '\0'}
73};
74
75__dead__attribute__((__noreturn__)) void usage(void);
76void push_excludes(char *);
77void push_ignore_pats(char *);
78void read_excludes_file(char *file);
79void set_argstr(char **, char **);
80
81int
82main(int argc, char **argv)
83{
84 char *ep, **oargv;
85 long l;
86 int ch, dflags, lastch, gotstdin, prevoptind, newarg;
87
88 oargv = argv;
89 gotstdin = 0;
90 dflags = 0;
91 lastch = '\0';
92 prevoptind = 1;
93 newarg = 1;
94 while ((ch = getopt_long(argc, argv, OPTIONS"0123456789abC:cdD:efhI:iL:lnNPpqrS:sTtU:uwX:x:", longopts, NULL((void *)0))) != -1) {
1
Assuming the condition is true
→
2
←
Loop condition is true. Entering loop body
→
8
←
Assuming the condition is true
→
9
←
Loop condition is true. Entering loop body
→
95 switch (ch) {
3
←
Control jumps to 'case 85:' at line 183
→
10
←
Control jumps to 'case 88:' at line 197
→
96 case '0': case '1': case '2': case '3': case '4':
97 case '5': case '6': case '7': case '8': case '9':
98 if (newarg)
99 usage(); /* disallow -[0-9]+ */
100 else if (lastch == 'c' || lastch == 'u')
101 diff_context = 0;
102 else if (!isdigit(lastch) || diff_context > INT_MAX2147483647 / 10)
103 usage();
104 diff_context = (diff_context * 10) + (ch - '0');
105 break;
106 case 'a':
107 dflags |= D_FORCEASCII0x008;
108 break;
109 case 'b':
110 dflags |= D_FOLDBLANKS0x010;
111 break;
112 case 'C':
113 case 'c':
114 diff_format = D_CONTEXT2;
115 if (optarg != NULL((void *)0)) {
116 l = strtol(optarg, &ep, 10);
117 if (*ep != '\0' || l < 0 || l >= INT_MAX2147483647)
118 usage();
119 diff_context = (int)l;
120 } else
121 diff_context = 3;
122 break;
123 case 'd':
124 dflags |= D_MINIMAL0x020;
125 break;
126 case 'D':
127 diff_format = D_IFDEF4;
128 ifdefname = optarg;
129 break;
130 case 'e':
131 diff_format = D_EDIT-1;
132 break;
133 case 'f':
134 diff_format = D_REVERSE1;
135 break;
136 case 'h':
137 /* silently ignore for backwards compatibility */
138 break;
139 case 'I':
140 push_ignore_pats(optarg);
141 break;
142 case 'i':
143 dflags |= D_IGNORECASE0x040;
144 break;
145 case 'L':
146 if (label[0] == NULL((void *)0))
147 label[0] = optarg;
148 else if (label[1] == NULL((void *)0))
149 label[1] = optarg;
150 else
151 usage();
152 break;
153 case 'N':
154 Nflag = 1;
155 break;
156 case 'n':
157 diff_format = D_NREVERSE5;
158 break;
159 case 'p':
160 dflags |= D_PROTOTYPE0x080;
161 break;
162 case 'P':
163 Pflag = 1;
164 break;
165 case 'r':
166 rflag = 1;
167 break;
168 case 'q':
169 diff_format = D_BRIEF6;
170 break;
171 case 'S':
172 start = optarg;
173 break;
174 case 's':
175 sflag = 1;
176 break;
177 case 'T':
178 Tflag = 1;
179 break;
180 case 't':
181 dflags |= D_EXPANDTABS0x100;
182 break;
183 case 'U':
184 case 'u':
185 diff_format = D_UNIFIED3;
186 if (optarg != NULL((void *)0)) {
4
←
Assuming 'optarg' is equal to NULL
→
5
←
Taking false branch
→
187 l = strtol(optarg, &ep, 10);
188 if (*ep != '\0' || l < 0 || l >= INT_MAX2147483647)
189 usage();
190 diff_context = (int)l;
191 } else
192 diff_context = 3;
193 break;
6
←
 Execution continues on line 207
→
194 case 'w':
195 dflags |= D_IGNOREBLANKS0x200;
196 break;
197 case 'X':
198 read_excludes_file(optarg);
11
←
Passing null pointer value via 1st parameter 'file'
→
12
←
Calling 'read_excludes_file'
→
199 break;
200 case 'x':
201 push_excludes(optarg);
202 break;
203 default:
204 usage();
205 break;
206 }
207 lastch = ch;
208 newarg = optind != prevoptind;
7
←
Assuming 'optind' is equal to 'prevoptind'
→
209 prevoptind = optind;
210 }
211 argc -= optind;
212 argv += optind;
213
214 if (pledge("stdio rpath tmppath", NULL((void *)0)) == -1)
215 err(2, "pledge");
216
217 /*
218 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
219 * driver routine. Both drivers use the contents of stb1 and stb2.
220 */
221 if (argc != 2)
222 usage();
223 if (ignore_pats != NULL((void *)0)) {
224 char buf[BUFSIZ1024];
225 int error;
226
227 if ((error = regcomp(&ignore_re, ignore_pats,
228 REG_NEWLINE0010 | REG_EXTENDED0001)) != 0) {
229 regerror(error, &ignore_re, buf, sizeof(buf));
230 if (*ignore_pats != '\0')
231 errx(2, "%s: %s", ignore_pats, buf);
232 else
233 errx(2, "%s", buf);
234 }
235 }
236 if (strcmp(argv[0], "-") == 0) {
237 fstat(STDIN_FILENO0, &stb1);
238 gotstdin = 1;
239 } else if (stat(argv[0], &stb1) != 0)
240 err(2, "%s", argv[0]);
241 if (strcmp(argv[1], "-") == 0) {
242 fstat(STDIN_FILENO0, &stb2);
243 gotstdin = 1;
244 } else if (stat(argv[1], &stb2) != 0)
245 err(2, "%s", argv[1]);
246 if (gotstdin && (S_ISDIR(stb1.st_mode)((stb1.st_mode & 0170000) == 0040000) || S_ISDIR(stb2.st_mode)((stb2.st_mode & 0170000) == 0040000)))
247 errx(2, "can't compare - to a directory");
248 set_argstr(oargv, argv);
249 if (S_ISDIR(stb1.st_mode)((stb1.st_mode & 0170000) == 0040000) && S_ISDIR(stb2.st_mode)((stb2.st_mode & 0170000) == 0040000)) {
250 if (diff_format == D_IFDEF4)
251 errx(2, "-D option not supported with directories");
252 diffdir(argv[0], argv[1], dflags);
253 } else {
254 if (S_ISDIR(stb1.st_mode)((stb1.st_mode & 0170000) == 0040000)) {
255 argv[0] = splice(argv[0], argv[1]);
256 if (stat(argv[0], &stb1) == -1)
257 err(2, "%s", argv[0]);
258 }
259 if (S_ISDIR(stb2.st_mode)((stb2.st_mode & 0170000) == 0040000)) {
260 argv[1] = splice(argv[1], argv[0]);
261 if (stat(argv[1], &stb2) == -1)
262 err(2, "%s", argv[1]);
263 }
264 print_status(diffreg(argv[0], argv[1], dflags), argv[0], argv[1],
265 "");
266 }
267 exit(status);
268}
269
270void
271set_argstr(char **av, char **ave)
272{
273 size_t argsize;
274 char **ap;
275
276 argsize = 4 + *ave - *av + 1;
277 diffargs = xmalloc(argsize);
278 strlcpy(diffargs, "diff", argsize);
279 for (ap = av + 1; ap < ave; ap++) {
280 if (strcmp(*ap, "--") != 0) {
281 strlcat(diffargs, " ", argsize);
282 strlcat(diffargs, *ap, argsize);
283 }
284 }
285}
286
287/*
288 * Read in an excludes file and push each line.
289 */
290void
291read_excludes_file(char *file)
292{
293 FILE *fp;
294 char *buf, *pattern;
295 size_t len;
296
297 if (strcmp(file, "-") == 0)
13
←
Null pointer passed as 1st argument to string comparison function
298 fp = stdin(&__sF[0]);
299 else if ((fp = fopen(file, "r")) == NULL((void *)0))
300 err(2, "%s", file);
301 while ((buf = fgetln(fp, &len)) != NULL((void *)0)) {
302 if (buf[len - 1] == '\n')
303 len--;
304 pattern = xmalloc(len + 1);
305 memcpy(pattern, buf, len);
306 pattern[len] = '\0';
307 push_excludes(pattern);
308 }
309 if (strcmp(file, "-") != 0)
310 fclose(fp);
311}
312
313/*
314 * Push a pattern onto the excludes list.
315 */
316void
317push_excludes(char *pattern)
318{
319 struct excludes *entry;
320
321 entry = xmalloc(sizeof(*entry));
322 entry->pattern = pattern;
323 entry->next = excludes_list;
324 excludes_list = entry;
325}
326
327void
328push_ignore_pats(char *pattern)
329{
330 size_t len;
331
332 if (ignore_pats == NULL((void *)0))
333 ignore_pats = xstrdup(pattern);
334 else {
335 /* old + "|" + new + NUL */
336 len = strlen(ignore_pats) + strlen(pattern) + 2;
337 ignore_pats = xreallocarray(ignore_pats, 1, len);
338 strlcat(ignore_pats, "|", len);
339 strlcat(ignore_pats, pattern, len);
340 }
341}
342
343void
344print_only(const char *path, size_t dirlen, const char *entry)
345{
346 if (dirlen > 1)
347 dirlen--;
348 printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
349}
350
351void
352print_status(int val, char *path1, char *path2, char *entry)
353{
354 switch (val) {
355 case D_BINARY2:
356 printf("Binary files %s%s and %s%s differ\n",
357 path1, entry, path2, entry);
358 break;
359 case D_DIFFER1:
360 if (diff_format == D_BRIEF6)
361 printf("Files %s%s and %s%s differ\n",
362 path1, entry, path2, entry);
363 break;
364 case D_SAME0:
365 if (sflag)
366 printf("Files %s%s and %s%s are identical\n",
367 path1, entry, path2, entry);
368 break;
369 case D_MISMATCH13:
370 printf("File %s%s is a directory while file %s%s is a regular file\n",
371 path1, entry, path2, entry);
372 break;
373 case D_MISMATCH24:
374 printf("File %s%s is a regular file while file %s%s is a directory\n",
375 path1, entry, path2, entry);
376 break;
377 case D_SKIPPED15:
378 printf("File %s%s is not a regular file or directory and was skipped\n",
379 path1, entry);
380 break;
381 case D_SKIPPED26:
382 printf("File %s%s is not a regular file or directory and was skipped\n",
383 path2, entry);
384 break;
385 }
386}
387
388__dead__attribute__((__noreturn__)) void
389usage(void)
390{
391 (void)fprintf(stderr(&__sF[2]),
392 "usage: diff [-abdipTtw] [-c | -e | -f | -n | -q | -u] [-I pattern] [-L label]\n"
393 " file1 file2\n"
394 " diff [-abdipTtw] [-I pattern] [-L label] -C number file1 file2\n"
395 " diff [-abditw] [-I pattern] -D string file1 file2\n"
396 " diff [-abdipTtw] [-I pattern] [-L label] -U number file1 file2\n"
397 " diff [-abdiNPprsTtw] [-c | -e | -f | -n | -q | -u] [-I pattern]\n"
398 " [-L label] [-S name] [-X file] [-x pattern] dir1 dir2\n");
399
400 exit(2);
401}