Bug Summary

File:src/sbin/swapctl/swapctl.c
Warning:line 400, column 5
This function call is prohibited after a successful vfork

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 swapctl.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/sbin/swapctl/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/sbin/swapctl/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/sbin/swapctl/swapctl.c
1/* $OpenBSD: swapctl.c,v 1.26 2020/02/11 18:16:38 jca Exp $ */
2/* $NetBSD: swapctl.c,v 1.9 1998/07/26 20:23:15 mycroft Exp $ */
3
4/*
5 * Copyright (c) 1996, 1997 Matthew R. Green
6 * 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 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/*
31 * swapctl command:
32 * -A add all devices listed as `sw' in /etc/fstab
33 * -t [blk|noblk] if -A, add either all block device or all non-block
34 * devices
35 * -a <path> add this device
36 * -d <path> remove this swap device
37 * -l list swap devices
38 * -s short listing of swap devices
39 * -k use kilobytes
40 * -p <pri> use this priority
41 * -c <path> change priority
42 *
43 * or, if invoked as "swapon" (compatibility mode):
44 *
45 * -a all devices listed as `sw' in /etc/fstab
46 * -t same as -t above (feature not present in old
47 * swapon(8) command)
48 * <dev> add this device
49 */
50
51#include <sys/stat.h>
52#include <sys/swap.h>
53#include <sys/wait.h>
54
55#include <unistd.h>
56#include <err.h>
57#include <errno(*__errno()).h>
58#include <stdio.h>
59#include <stdlib.h>
60#include <limits.h>
61#include <string.h>
62#include <fstab.h>
63#include <util.h>
64
65#include "swapctl.h"
66
67int command;
68
69/*
70 * Commands for swapctl(8). These are mutually exclusive.
71 */
72#define CMD_A0x01 0x01 /* process /etc/fstab */
73#define CMD_a0x02 0x02 /* add a swap file/device */
74#define CMD_c0x04 0x04 /* change priority of a swap file/device */
75#define CMD_d0x08 0x08 /* delete a swap file/device */
76#define CMD_l0x10 0x10 /* list swap files/devices */
77#define CMD_s0x20 0x20 /* summary of swap files/devices */
78
79#define SET_COMMAND(cmd)do { if (command) usage(); command = (cmd); } while (0) \
80do { \
81 if (command) \
82 usage(); \
83 command = (cmd); \
84} while (0)
85
86/*
87 * Commands that require a "path" argument at the end of the command
88 * line, and the ones which require that none exist.
89 */
90#define REQUIRE_PATH(0x02 | 0x04 | 0x08) (CMD_a0x02 | CMD_c0x04 | CMD_d0x08)
91#define REQUIRE_NOPATH(0x01 | 0x10 | 0x20) (CMD_A0x01 | CMD_l0x10 | CMD_s0x20)
92
93/*
94 * Option flags, and the commands with which they are valid.
95 */
96int kflag; /* display in 1K blocks */
97#define KFLAG_CMDS(0x10 | 0x20) (CMD_l0x10 | CMD_s0x20)
98
99int pflag; /* priority was specified */
100#define PFLAG_CMDS(0x01 | 0x02 | 0x04) (CMD_A0x01 | CMD_a0x02 | CMD_c0x04)
101
102char *tflag; /* swap device type (blk or noblk) */
103#define TFLAG_CMDS(0x01) (CMD_A0x01)
104
105int pri; /* uses 0 as default pri */
106
107static void change_priority(char *);
108static void add_swap(char *);
109static void del_swap(char *);
110static void do_fstab(void);
111static void usage(void);
112static int swapon_command(int, char **);
113
114extern char *__progname; /* from crt0.o */
115
116int
117main(int argc, char *argv[])
118{
119 const char *errstr;
120 int c;
121
122 if (strcmp(__progname, "swapon") == 0)
1
Assuming the condition is false
→
2
←
Taking false branch
→
123 return swapon_command(argc, argv);
124
125 while ((c = getopt(argc, argv, "Aacdlkp:st:")) != -1) {
3
←
Assuming the condition is false
→
4
←
Loop condition is false. Execution continues on line 174
→
126 switch (c) {
127 case 'A':
128 SET_COMMAND(CMD_A)do { if (command) usage(); command = (0x01); } while (0);
129 break;
130
131 case 'a':
132 SET_COMMAND(CMD_a)do { if (command) usage(); command = (0x02); } while (0);
133 break;
134
135 case 'c':
136 SET_COMMAND(CMD_c)do { if (command) usage(); command = (0x04); } while (0);
137 break;
138
139 case 'd':
140 SET_COMMAND(CMD_d)do { if (command) usage(); command = (0x08); } while (0);
141 break;
142
143 case 'l':
144 SET_COMMAND(CMD_l)do { if (command) usage(); command = (0x10); } while (0);
145 break;
146
147 case 'k':
148 kflag = 1;
149 break;
150
151 case 'p':
152 pflag = 1;
153 pri = strtonum(optarg, 0, INT_MAX2147483647, &errstr);
154 if (errstr)
155 errx(1, "-p %s: %s", errstr, optarg);
156 break;
157
158 case 's':
159 SET_COMMAND(CMD_s)do { if (command) usage(); command = (0x20); } while (0);
160 break;
161
162 case 't':
163 if (tflag != NULL((void *)0))
164 usage();
165 tflag = optarg;
166 break;
167
168 default:
169 usage();
170 /* NOTREACHED */
171 }
172 }
173
174 argv += optind;
175 argc -= optind;
176
177 /* Did the user specify a command? */
178 if (command == 0) {
5
←
Assuming 'command' is not equal to 0
→
6
←
Taking false branch
→
179 if (argc == 0)
180 SET_COMMAND(CMD_l)do { if (command) usage(); command = (0x10); } while (0);
181 else
182 usage();
183 }
184
185 switch (argc) {
7
←
Control jumps to 'case 1:' at line 191
→
186 case 0:
187 if (command & REQUIRE_PATH(0x02 | 0x04 | 0x08))
188 usage();
189 break;
190
191 case 1:
192 if (command & REQUIRE_NOPATH(0x01 | 0x10 | 0x20))
8
←
Assuming the condition is false
→
9
←
Taking false branch
→
193 usage();
194 break;
10
←
 Execution continues on line 201
→
195
196 default:
197 usage();
198 }
199
200 /* To change priority, you have to specify one. */
201 if ((command == CMD_c0x04) && pflag == 0)
11
←
Assuming 'command' is not equal to CMD_c
→
202 usage();
203
204 /* Sanity-check -t */
205 if (tflag != NULL((void *)0)) {
12
←
Assuming 'tflag' is equal to NULL
→
13
←
Taking false branch
→
206 if (command != CMD_A0x01)
207 usage();
208 if (strcmp(tflag, "blk") != 0 &&
209 strcmp(tflag, "noblk") != 0)
210 usage();
211 }
212
213 /* Dispatch the command. */
214 switch (command) {
14
←
Control jumps to 'case 1:' at line 235
→
215 case CMD_l0x10:
216 list_swap(pri, kflag, pflag, 1);
217 break;
218
219 case CMD_s0x20:
220 list_swap(pri, kflag, pflag, 0);
221 break;
222
223 case CMD_c0x04:
224 change_priority(argv[0]);
225 break;
226
227 case CMD_a0x02:
228 add_swap(argv[0]);
229 break;
230
231 case CMD_d0x08:
232 del_swap(argv[0]);
233 break;
234
235 case CMD_A0x01:
236 do_fstab();
15
←
Calling 'do_fstab'
→
237 break;
238 }
239
240 return (0);
241}
242
243/*
244 * swapon_command: emulate the old swapon(8) program.
245 */
246int
247swapon_command(int argc, char **argv)
248{
249 int ch, fiztab = 0;
250
251 while ((ch = getopt(argc, argv, "at:")) != -1) {
252 switch (ch) {
253 case 'a':
254 fiztab = 1;
255 break;
256 case 't':
257 if (tflag != NULL((void *)0))
258 usage();
259 tflag = optarg;
260 break;
261 default:
262 goto swapon_usage;
263 }
264 }
265 argc -= optind;
266 argv += optind;
267
268 if (fiztab) {
269 if (argc)
270 goto swapon_usage;
271 /* Sanity-check -t */
272 if (tflag != NULL((void *)0)) {
273 if (strcmp(tflag, "blk") != 0 &&
274 strcmp(tflag, "noblk") != 0)
275 usage();
276 }
277 do_fstab();
278 return (0);
279 } else if (argc == 0 || tflag != NULL((void *)0))
280 goto swapon_usage;
281
282 while (argc) {
283 add_swap(argv[0]);
284 argc--;
285 argv++;
286 }
287 return (0);
288
289 swapon_usage:
290 fprintf(stderr(&__sF[2]), "usage: %s -a | path\n", __progname);
291 return (1);
292}
293
294/*
295 * change_priority: change the priority of a swap device.
296 */
297void
298change_priority(char *path)
299{
300
301 if (swapctl(SWAP_CTL5, path, pri) == -1)
302 warn("%s", path);
303}
304
305/*
306 * add_swap: add the pathname to the list of swap devices.
307 */
308void
309add_swap(char *path)
310{
311
312 if (swapctl(SWAP_ON1, path, pri) == -1)
313 if (errno(*__errno()) != EBUSY16)
314 err(1, "%s", path);
315}
316
317/*
318 * del_swap: remove the pathname from the list of swap devices.
319 */
320void
321del_swap(char *path)
322{
323
324 if (swapctl(SWAP_OFF2, path, pri) == -1)
325 err(1, "%s", path);
326}
327
328void
329do_fstab(void)
330{
331 struct fstab *fp;
332 char *s;
333 long priority;
334 struct stat st;
335 mode_t rejecttype = 0;
336 int gotone = 0;
337
338 /*
339 * Select which mount point types to reject, depending on the
340 * value of the -t parameter.
341 */
342 if (tflag
15.1
'tflag' is equal to NULL
 != NULL((void *)0)) {
16
←
Taking false branch
→
343 if (strcmp(tflag, "blk") == 0)
344 rejecttype = S_IFREG0100000;
345 else if (strcmp(tflag, "noblk") == 0)
346 rejecttype = S_IFBLK0060000;
347 }
348
349#define PRIORITYEQ"priority=" "priority="
350#define NFSMNTPT"nfsmntpt=" "nfsmntpt="
351#define PATH_MOUNT"/sbin/mount_nfs" "/sbin/mount_nfs"
352 while ((fp = getfsent()) != NULL((void *)0)) {
17
←
Assuming the condition is true
→
18
←
Loop condition is true. Entering loop body
→
353 const char *spec;
354
355 if (strcmp(fp->fs_type, "sw") != 0)
19
←
Taking false branch
→
356 continue;
357
358 spec = fp->fs_spec;
359
360 if ((s = strstr(fp->fs_mntops, PRIORITYEQ"priority=")) != NULL((void *)0)) {
20
←
Assuming the condition is false
→
21
←
Taking false branch
→
361 s += sizeof(PRIORITYEQ"priority=") - 1;
362 priority = atol(s);
363 } else
364 priority = pri;
365
366 if ((s = strstr(fp->fs_mntops, NFSMNTPT"nfsmntpt=")) != NULL((void *)0)) {
22
←
Assuming the condition is true
→
23
←
Taking true branch
→
367 char *t;
368 pid_t pid;
369 int status;
370
371 /*
372 * Skip this song and dance if we're only
373 * doing block devices.
374 */
375 if (rejecttype
23.1
'rejecttype' is not equal to S_IFREG
 == S_IFREG0100000)
24
←
Taking false branch
→
376 continue;
377
378 t = strpbrk(s, ",");
379 if (t != 0)
25
←
Assuming 't' is equal to null
→
26
←
Taking false branch
→
380 *t = '\0';
381 spec = strdup(s + strlen(NFSMNTPT"nfsmntpt="));
382 if (spec == NULL((void *)0))
27
←
Assuming 'spec' is not equal to NULL
→
28
←
Taking false branch
→
383 err(1, "strdup");
384
385 if (t
28.1
't' is equal to null
 != 0)
29
←
Taking false branch
→
386 *t = ',';
387
388 if (strlen(spec) == 0) {
30
←
Assuming the condition is false
→
31
←
Taking false branch
→
389 warnx("empty mountpoint");
390 free((char *)spec);
391 continue;
392 }
393
394 switch (pid = vfork()) {
32
←
Control jumps to 'case 0:' at line 397
→
395 case -1: /* error */
396 err(1, "vfork");
397 case 0:
398 execl(PATH_MOUNT"/sbin/mount_nfs", PATH_MOUNT"/sbin/mount_nfs", fp->fs_spec, spec,
399 (char *)NULL((void *)0));
400 err(1, "execl");
33
←
This function call is prohibited after a successful vfork
401 }
402 while (waitpid(pid, &status, 0) == -1)
403 if (errno(*__errno()) != EINTR4)
404 err(1, "waitpid");
405 if (status != 0) {
406 warnx("%s: mount failed", fp->fs_spec);
407 free((char *)spec);
408 continue;
409 }
410 } else if (isduid(spec, 0)) {
411 if (rejecttype == S_IFBLK0060000)
412 continue;
413 } else {
414 /*
415 * Determine blk-ness. Don't even consider a
416 * mountpoint outside /dev as a block device.
417 */
418 if (rejecttype == S_IFREG0100000) {
419 if (strncmp("/dev/", spec, 5) != 0)
420 continue;
421 }
422 if (stat(spec, &st) == -1) {
423 warn("%s", spec);
424 continue;
425 }
426 if ((st.st_mode & S_IFMT0170000) == rejecttype)
427 continue;
428
429 /*
430 * Do not allow fancy objects to be swap areas.
431 */
432 if (!S_ISREG(st.st_mode)((st.st_mode & 0170000) == 0100000) &&
433 !S_ISBLK(st.st_mode)((st.st_mode & 0170000) == 0060000))
434 continue;
435 }
436
437 if (swapctl(SWAP_ON1, spec, (int)priority) == -1) {
438 if (errno(*__errno()) != EBUSY16)
439 warn("%s", spec);
440 } else {
441 gotone = 1;
442 printf("%s: adding %s as swap device at priority %d\n",
443 __progname, fp->fs_spec, (int)priority);
444 }
445
446 if (spec != fp->fs_spec)
447 free((char *)spec);
448 }
449 if (gotone == 0)
450 exit(1);
451}
452
453void
454usage(void)
455{
456
457 fprintf(stderr(&__sF[2]), "usage: %s -A [-p priority] [-t blk | noblk]\n",
458 __progname);
459 fprintf(stderr(&__sF[2]), " %s -a [-p priority] path\n", __progname);
460 fprintf(stderr(&__sF[2]), " %s -c -p priority path\n", __progname);
461 fprintf(stderr(&__sF[2]), " %s -d path\n", __progname);
462 fprintf(stderr(&__sF[2]), " %s [[-l] | -s] [-k]\n", __progname);
463 exit(1);
464}