Bug Summary

File:src/lib/libc/stdlib/system.c
Warning:line 64, column 3
This function call is prohibited after a successful vfork

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name system.c -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 -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -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/lib/libc/obj -resource-dir /usr/local/llvm16/lib/clang/16 -include namespace.h -I /usr/src/lib/libc/include -I /usr/src/lib/libc/hidden -D __LIBC__ -D APIWARN -D YP -I /usr/src/lib/libc/yp -I /usr/src/lib/libc -I /usr/src/lib/libc/gdtoa -I /usr/src/lib/libc/arch/amd64/gdtoa -D INFNAN_CHECK -D MULTIPLE_THREADS -D NO_FENV_H -D USE_LOCALE -I /usr/src/lib/libc -I /usr/src/lib/libc/citrus -D RESOLVSORT -D FLOATING_POINT -D PRINTF_WIDE_CHAR -D SCANF_WIDE_CHAR -D FUTEX -internal-isystem /usr/local/llvm16/lib/clang/16/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libc/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fno-jump-tables -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/scan/2024-01-11-140451-98009-1 -x c /usr/src/lib/libc/stdlib/system.c
1/* $OpenBSD: system.c,v 1.13 2022/05/21 00:53:53 millert Exp $ */
2/*
3 * Copyright (c) 1988 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/types.h>
32#include <sys/wait.h>
33#include <errno(*__errno()).h>
34#include <signal.h>
35#include <stdlib.h>
36#include <string.h>
37#include <unistd.h>
38#include <paths.h>
39
40int
41system(const char *command)
42{
43 pid_t pid, cpid;
44 struct sigaction intsave, quitsave, sa;
45 sigset_t mask, omask;
46 int pstat;
47 char *argp[] = {"sh", "-c", NULL((void *)0), NULL((void *)0)};
48
49 if (!command) /* just checking... */
1
Assuming 'command' is non-null
→
2
←
Taking false branch
→
50 return(1);
51
52 argp[2] = (char *)command;
53
54 sigemptyset(&mask);
55 sigaddset(&mask, SIGCHLD20);
56 sigaddset(&mask, SIGINT2);
57 sigaddset(&mask, SIGQUIT3);
58 sigprocmask(SIG_BLOCK1, &mask, &omask);
59 switch (cpid = vfork()) {
3
←
Control jumps to 'case 0:' at line 63
→
60 case -1: /* error */
61 sigprocmask(SIG_SETMASK3, &omask, NULL((void *)0));
62 return(-1);
63 case 0: /* child */
64 sigprocmask(SIG_SETMASK3, &omask, NULL((void *)0));
4
←
This function call is prohibited after a successful vfork
65 execve(_PATH_BSHELL"/bin/sh", argp, environ);
66 _exit(127);
67 }
68
69 /* Ignore SIGINT and SIGQUIT while waiting for command to complete. */
70 memset(&sa, 0, sizeof(sa));
71 sigemptyset(&sa.sa_mask);
72 sa.sa_handler__sigaction_u.__sa_handler = SIG_IGN(void (*)(int))1;
73 sigaction(SIGINT2, &sa, &intsave);
74 sigaction(SIGQUIT3, &sa, &quitsave);
75 sigemptyset(&mask);
76 sigaddset(&mask, SIGINT2);
77 sigaddset(&mask, SIGQUIT3);
78 sigprocmask(SIG_UNBLOCK2, &mask, NULL((void *)0));
79
80 do {
81 pid = waitpid(cpid, &pstat, 0);
82 } while (pid == -1 && errno(*__errno()) == EINTR4);
83
84 sigprocmask(SIG_SETMASK3, &omask, NULL((void *)0));
85 sigaction(SIGINT2, &intsave, NULL((void *)0));
86 sigaction(SIGQUIT3, &quitsave, NULL((void *)0));
87 return (pid == -1 ? -1 : pstat);
88}
89DEF_STRONG(system)__asm__(".global " "system" " ; " "system" " = " "_libc_system"
);