Bug Summary

File:src/usr.bin/patch/util.c
Warning:line 111, column 7
Null pointer passed as 2nd argument to string copy 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 util.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/patch/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/patch/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/patch/util.c
1/* $OpenBSD: util.c,v 1.46 2021/10/24 21:24:17 deraadt Exp $ */
2
3/*
4 * patch - a program to apply diffs to original files
5 *
6 * Copyright 1986, Larry Wall
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following condition is met:
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this condition and the following disclaimer.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
17 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
19 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
20 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * -C option added in 1998, original code by Marc Espie, based on FreeBSD
26 * behaviour
27 */
28
29#include <sys/stat.h>
30
31#include <ctype.h>
32#include <errno(*__errno()).h>
33#include <fcntl.h>
34#include <paths.h>
35#include <signal.h>
36#include <stdarg.h>
37#include <stdlib.h>
38#include <stdio.h>
39#include <string.h>
40#include <unistd.h>
41
42#include "common.h"
43#include "util.h"
44#include "backupfile.h"
45
46/* Rename a file, copying it if necessary. */
47
48int
49move_file(const char *from, const char *to)
50{
51 int fromfd;
52 ssize_t i;
53
54 /* to stdout? */
55
56 if (strEQ(to, "-")(!strcmp(to, "-"))) {
1
Assuming the condition is false
→
2
←
Taking false branch
→
57#ifdef DEBUGGING
58 if (debug & 4)
59 say("Moving %s to stdout.\n", from);
60#endif
61 fromfd = open(from, O_RDONLY0x0000);
62 if (fromfd == -1)
63 pfatal("internal error, can't reopen %s", from);
64 while ((i = read(fromfd, buf, bufsz)) > 0)
65 if (write(STDOUT_FILENO1, buf, i) != i)
66 pfatal("write failed");
67 close(fromfd);
68 return 0;
69 }
70 if (backup_file(to) < 0) {
3
←
Calling 'backup_file'
→
71 say("Can't backup %s, output is in %s: %s\n", to, from,
72 strerror(errno(*__errno())));
73 return -1;
74 }
75#ifdef DEBUGGING
76 if (debug & 4)
77 say("Moving %s to %s.\n", from, to);
78#endif
79 if (rename(from, to) == -1) {
80 if (errno(*__errno()) != EXDEV18 || copy_file(from, to) < 0) {
81 say("Can't create %s, output is in %s: %s\n",
82 to, from, strerror(errno(*__errno())));
83 return -1;
84 }
85 }
86 return 0;
87}
88
89/* Backup the original file. */
90
91int
92backup_file(const char *orig)
93{
94 struct stat filestat;
95 char bakname[PATH_MAX1024], *s, *simplename;
96 dev_t orig_device;
97 ino_t orig_inode;
98
99 if (backup_type == none || stat(orig, &filestat) != 0)
4
←
Assuming 'backup_type' is not equal to none
→
5
←
Assuming the condition is false
→
6
←
Taking false branch
→
100 return 0; /* nothing to do */
101 orig_device = filestat.st_dev;
102 orig_inode = filestat.st_ino;
103
104 if (origprae) {
7
←
Assuming 'origprae' is null
→
8
←
Taking false branch
→
105 if (strlcpy(bakname, origprae, sizeof(bakname)) >= sizeof(bakname) ||
106 strlcat(bakname, orig, sizeof(bakname)) >= sizeof(bakname))
107 fatal("filename %s too long for buffer\n", origprae);
108 } else {
109 if ((s = find_backup_file_name(orig)) == NULL((void *)0))
9
←
Value assigned to 's'
→
10
←
Assuming pointer value is null
→
11
←
Taking true branch
→
110 fatal("out of memory\n");
111 if (strlcpy(bakname, s, sizeof(bakname)) >= sizeof(bakname))
12
←
Null pointer passed as 2nd argument to string copy function
112 fatal("filename %s too long for buffer\n", s);
113 free(s);
114 }
115
116 if ((simplename = strrchr(bakname, '/')) != NULL((void *)0))
117 simplename = simplename + 1;
118 else
119 simplename = bakname;
120
121 /*
122 * Find a backup name that is not the same file. Change the
123 * first lowercase char into uppercase; if that isn't
124 * sufficient, chop off the first char and try again.
125 */
126 while (stat(bakname, &filestat) == 0 &&
127 orig_device == filestat.st_dev && orig_inode == filestat.st_ino) {
128 /* Skip initial non-lowercase chars. */
129 for (s = simplename; *s && !islower((unsigned char)*s); s++)
130 ;
131 if (*s)
132 *s = toupper((unsigned char)*s);
133 else
134 memmove(simplename, simplename + 1,
135 strlen(simplename + 1) + 1);
136 }
137#ifdef DEBUGGING
138 if (debug & 4)
139 say("Moving %s to %s.\n", orig, bakname);
140#endif
141 if (rename(orig, bakname) == -1) {
142 if (errno(*__errno()) != EXDEV18 || copy_file(orig, bakname) < 0)
143 return -1;
144 }
145 return 0;
146}
147
148/*
149 * Copy a file.
150 */
151int
152copy_file(const char *from, const char *to)
153{
154 int tofd, fromfd;
155 ssize_t i;
156
157 tofd = open(to, O_CREAT0x0200|O_TRUNC0x0400|O_WRONLY0x0001, 0666);
158 if (tofd == -1)
159 return -1;
160 fromfd = open(from, O_RDONLY0x0000);
161 if (fromfd == -1)
162 pfatal("internal error, can't reopen %s", from);
163 while ((i = read(fromfd, buf, bufsz)) > 0)
164 if (write(tofd, buf, i) != i)
165 pfatal("write to %s failed", to);
166 close(fromfd);
167 close(tofd);
168 return 0;
169}
170
171/*
172 * Allocate a unique area for a string.
173 */
174char *
175savestr(const char *s)
176{
177 char *rv;
178
179 if (!s)
180 s = "Oops";
181 rv = strdup(s);
182 if (rv == NULL((void *)0)) {
183 if (using_plan_a)
184 out_of_mem = true1;
185 else
186 fatal("out of memory\n");
187 }
188 return rv;
189}
190
191/*
192 * Allocate a unique area for a string. Call fatal if out of memory.
193 */
194char *
195xstrdup(const char *s)
196{
197 char *rv;
198
199 if (!s)
200 s = "Oops";
201 rv = strdup(s);
202 if (rv == NULL((void *)0))
203 fatal("out of memory\n");
204 return rv;
205}
206
207/*
208 * Vanilla terminal output (buffered).
209 */
210void
211say(const char *fmt, ...)
212{
213 va_list ap;
214
215 va_start(ap, fmt)__builtin_va_start(ap, fmt);
216 vfprintf(stdout(&__sF[1]), fmt, ap);
217 va_end(ap)__builtin_va_end(ap);
218 fflush(stdout(&__sF[1]));
219}
220
221/*
222 * Terminal output, pun intended.
223 */
224void
225fatal(const char *fmt, ...)
226{
227 va_list ap;
228
229 va_start(ap, fmt)__builtin_va_start(ap, fmt);
230 fprintf(stderr(&__sF[2]), "patch: **** ");
231 vfprintf(stderr(&__sF[2]), fmt, ap);
232 va_end(ap)__builtin_va_end(ap);
233 my_exit(2);
234}
235
236/*
237 * Say something from patch, something from the system, then silence . . .
238 */
239void
240pfatal(const char *fmt, ...)
241{
242 va_list ap;
243 int errnum = errno(*__errno());
244
245 fprintf(stderr(&__sF[2]), "patch: **** ");
246 va_start(ap, fmt)__builtin_va_start(ap, fmt);
247 vfprintf(stderr(&__sF[2]), fmt, ap);
248 va_end(ap)__builtin_va_end(ap);
249 fprintf(stderr(&__sF[2]), ": %s\n", strerror(errnum));
250 my_exit(2);
251}
252
253/*
254 * Get a response from the user via /dev/tty
255 */
256void
257ask(const char *fmt, ...)
258{
259 va_list ap;
260 ssize_t nr;
261 static int ttyfd = -1;
262
263 va_start(ap, fmt)__builtin_va_start(ap, fmt);
264 vfprintf(stdout(&__sF[1]), fmt, ap);
265 va_end(ap)__builtin_va_end(ap);
266 fflush(stdout(&__sF[1]));
267 if (ttyfd < 0)
268 ttyfd = open(_PATH_TTY"/dev/tty", O_RDONLY0x0000);
269 if (ttyfd >= 0) {
270 if ((nr = read(ttyfd, buf, bufsz)) > 0 &&
271 buf[nr - 1] == '\n')
272 buf[nr - 1] = '\0';
273 }
274 if (ttyfd == -1 || nr <= 0) {
275 /* no tty or error reading, pretend user entered 'return' */
276 putchar('\n')(!__isthreaded ? __sputc('\n', (&__sF[1])) : (putc)('\n',
(&__sF[1])));
277 buf[0] = '\0';
278 }
279}
280
281/*
282 * How to handle certain events when not in a critical region.
283 */
284void
285set_signals(int reset)
286{
287 static sig_t hupval, intval;
288
289 if (!reset) {
290 hupval = signal(SIGHUP1, SIG_IGN(void (*)(int))1);
291 if (hupval != SIG_IGN(void (*)(int))1)
292 hupval = my_sigexit;
293 intval = signal(SIGINT2, SIG_IGN(void (*)(int))1);
294 if (intval != SIG_IGN(void (*)(int))1)
295 intval = my_sigexit;
296 }
297 signal(SIGHUP1, hupval);
298 signal(SIGINT2, intval);
299}
300
301/*
302 * How to handle certain events when in a critical region.
303 */
304void
305ignore_signals(void)
306{
307 signal(SIGHUP1, SIG_IGN(void (*)(int))1);
308 signal(SIGINT2, SIG_IGN(void (*)(int))1);
309}
310
311/*
312 * Make sure we'll have the directories to create a file. If `striplast' is
313 * true, ignore the last element of `filename'.
314 */
315
316void
317makedirs(const char *filename, bool_Bool striplast)
318{
319 char *tmpbuf;
320
321 if ((tmpbuf = strdup(filename)) == NULL((void *)0))
322 fatal("out of memory\n");
323
324 if (striplast) {
325 char *s = strrchr(tmpbuf, '/');
326 if (s == NULL((void *)0)) {
327 free(tmpbuf);
328 return; /* nothing to be done */
329 }
330 *s = '\0';
331 }
332 if (mkpath(tmpbuf) != 0)
333 pfatal("creation of %s failed", tmpbuf);
334 free(tmpbuf);
335}
336
337/*
338 * Make filenames more reasonable.
339 */
340char *
341fetchname(const char *at, bool_Bool *exists, int strip_leading)
342{
343 char *fullname, *name, *t;
344 int sleading, tab;
345 struct stat filestat;
346
347 if (at == NULL((void *)0) || *at == '\0')
348 return NULL((void *)0);
349 while (isspace((unsigned char)*at))
350 at++;
351#ifdef DEBUGGING
352 if (debug & 128)
353 say("fetchname %s %d\n", at, strip_leading);
354#endif
355 /* So files can be created by diffing against /dev/null. */
356 if (strnEQ(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL) - 1)(!strncmp(at, "/dev/null", sizeof("/dev/null") - 1)))
357 return NULL((void *)0);
358 name = fullname = t = savestr(at);
359
360 tab = strchr(t, '\t') != NULL((void *)0);
361 /* Strip off up to `strip_leading' path components and NUL terminate. */
362 for (sleading = strip_leading; *t != '\0' && ((tab && *t != '\t') ||
363 !isspace((unsigned char)*t)); t++) {
364 if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
365 if (--sleading >= 0)
366 name = t + 1;
367 }
368 *t = '\0';
369
370 /*
371 * If no -p option was given (957 is the default value!), we were
372 * given a relative pathname, and the leading directories that we
373 * just stripped off all exist, put them back on.
374 */
375 if (strip_leading == 957 && name != fullname && *fullname != '/') {
376 name[-1] = '\0';
377 if (stat(fullname, &filestat) == 0 && S_ISDIR(filestat.st_mode)((filestat.st_mode & 0170000) == 0040000)) {
378 name[-1] = '/';
379 name = fullname;
380 }
381 }
382 name = savestr(name);
383 free(fullname);
384
385 *exists = stat(name, &filestat) == 0;
386 return name;
387}
388
389void
390version(void)
391{
392 fprintf(stderr(&__sF[2]), "Patch version 2.0-12u8-OpenBSD\n");
393 my_exit(EXIT_SUCCESS0);
394}
395
396void
397my_cleanup(void)
398{
399 unlink(TMPINNAME);
400 if (!toutkeep)
401 unlink(TMPOUTNAME);
402 if (!trejkeep)
403 unlink(TMPREJNAME);
404 unlink(TMPPATNAME);
405}
406
407/*
408 * Exit with cleanup.
409 */
410void
411my_exit(int status)
412{
413 my_cleanup();
414 exit(status);
415}
416
417/*
418 * Exit with cleanup, from a signal handler.
419 */
420void
421my_sigexit(int signo)
422{
423 my_cleanup();
424 _exit(2);
425}