Bug Summary

File:src/games/cribbage/instr.c
Warning:line 55, column 16
Call to function 'vfork' is insecure as it can lead to denial of service situations in the parent process. Replace calls to vfork with calls to the safer 'posix_spawn' 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 instr.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/games/cribbage/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/games/cribbage/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/games/cribbage/instr.c
1/* $OpenBSD: instr.c,v 1.14 2016/01/10 13:35:09 mestre Exp $ */
2/* $NetBSD: instr.c,v 1.5 1997/07/10 06:47:30 mikel Exp $ */
3
4/*-
5 * Copyright (c) 1990, 1993
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/wait.h>
34
35#include <err.h>
36#include <errno(*__errno()).h>
37#include <fcntl.h>
38#include <paths.h>
39#include <stdlib.h>
40#include <unistd.h>
41
42#include "pathnames.h"
43
44void
45instructions(void)
46{
47 int pstat;
48 int fd;
49 pid_t pid;
50 const char *pager;
51
52 if ((fd = open(_PATH_INSTR"/usr/share/games/cribbage.instr", O_RDONLY0x0000)) == - 1)
53 errx(1, "can't open %s", _PATH_INSTR"/usr/share/games/cribbage.instr");
54
55 switch (pid = vfork()) {
Call to function 'vfork' is insecure as it can lead to denial of service situations in the parent process. Replace calls to vfork with calls to the safer 'posix_spawn' function
56 case -1:
57 err(1, "vfork");
58 case 0:
59 if (!isatty(1))
60 pager = "/bin/cat";
61 else {
62 if (!(pager = getenv("PAGER")) || (*pager == 0))
63 pager = _PATH_MORE"/usr/bin/more";
64 }
65 if (dup2(fd, 0) == -1)
66 err(1, "dup2");
67 execl(_PATH_BSHELL"/bin/sh", "sh", "-c", pager, (char *)NULL((void *)0));
68 err(1, "exec sh -c %s", pager);
69 default:
70 do {
71 pid = waitpid(pid, &pstat, 0);
72 } while (pid == -1 && errno(*__errno()) == EINTR4);
73 close(fd);
74 if (pid == -1 || WEXITSTATUS(pstat)(int)(((unsigned)(pstat) >> 8) & 0xff))
75 exit(1);
76 break;
77 }
78}