clang/test/Analysis/vfork.c

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core,security.insecureAPI.vfork,unix.Vfork -verify %s
   2 // RUN: %clang_analyze_cc1 -analyzer-checker=core,security.insecureAPI.vfork,unix.Vfork -verify -x c++ %s
   3
   4 #include "Inputs/system-header-simulator.h"
   5
   6 void foo(void);
   7
   8 // Ensure that child process is properly checked.
   9 int f1(int x, int y) {
  10   pid_t pid = vfork(); // expected-warning{{Call to function 'vfork' is insecure}}
  11   if (pid != 0)
  12     return 0;
  13
  14   switch (x) {
  15   case 0:
  16     // Ensure that modifying pid is ok.
  17     pid = 1; // no-warning
  18     // Ensure that calling allowlisted routines is ok.
  19     switch (y) {
  20     case 0:
  21       execl("", "", 0); // no-warning
  22       break;
  23     case 1:
  24       execle("", "", 0); // no-warning
  25       break;
  26     case 2:
  27       execlp("", "", 0); // no-warning
  28       break;
  29     case 3:
  30       execv("", NULL); // no-warning
  31       break;
  32     case 4:
  33       execve("", NULL, NULL); // no-warning
  34       break;
  35     case 5:
  36       execvp("", NULL); // no-warning
  37       break;
  38     case 6:
  39       execvpe("", NULL, NULL); // no-warning
  40       break;
  41     }
  42     _exit(1); // no-warning
  43     break;
  44   case 1:
  45     // Ensure that writing variables is prohibited.
  46     x = 0; // expected-warning{{This assignment is prohibited after a successful vfork}}
  47     break;
  48   case 2:
  49     // Ensure that calling functions is prohibited.
  50     foo(); // expected-warning{{This function call is prohibited after a successful vfork}}
  51     break;
  52   default:
  53     // Ensure that returning from function is prohibited.
  54     return 0; // expected-warning{{Return is prohibited after a successful vfork; call _exit() instead}}
  55   }
  56
  57   while(1);
  58 }
  59
  60 // Same as previous but without explicit pid variable.
  61 int f2(int x) {
  62   pid_t pid = vfork(); // expected-warning{{Call to function 'vfork' is insecure}}
  63
  64   switch (x) {
  65   case 0:
  66     // Ensure that writing pid is ok.
  67     pid = 1; // no-warning
  68     // Ensure that calling allowlisted routines is ok.
  69     execl("", "", 0); // no-warning
  70     _exit(1); // no-warning
  71     break;
  72   case 1:
  73     // Ensure that writing variables is prohibited.
  74     x = 0; // expected-warning{{This assignment is prohibited after a successful vfork}}
  75     break;
  76   case 2:
  77     // Ensure that calling functions is prohibited.
  78     foo(); // expected-warning{{This function call is prohibited after a successful vfork}}
  79     break;
  80   default:
  81     // Ensure that returning from function is prohibited.
  82     return 0; // expected-warning{{Return is prohibited after a successful vfork; call _exit() instead}}
  83   }
  84
  85   while(1);
  86 }
  87
  88 // Ensure that parent process isn't restricted.
  89 int f3(int x) {
  90   if (vfork() == 0) // expected-warning{{Call to function 'vfork' is insecure}}
  91     _exit(1);
  92   x = 0; // no-warning
  93   foo(); // no-warning
  94   return 0;
  95 } // no-warning
  96
  97 // Unbound pids are special so test them separately.
  98 void f4(int x) {
  99   switch (x) {
 100   case 0:
 101     vfork(); // expected-warning{{Call to function 'vfork' is insecure}}
 102     x = 0; // expected-warning{{This assignment is prohibited after a successful vfork}}
 103     break;
 104
 105   case 1:
 106     {
 107       char args[2];
 108       switch (vfork()) { // expected-warning{{Call to function 'vfork' is insecure}}
 109       case 0:
 110         args[0] = 0; // expected-warning{{This assignment is prohibited after a successful vfork}}
 111         exit(1);
 112       }
 113       break;
 114     }
 115
 116   case 2:
 117     {
 118       pid_t pid;
 119       if ((pid = vfork()) == 0) // expected-warning{{Call to function 'vfork' is insecure}}
 120         while(1); // no-warning
 121       break;
 122     }
 123   }
 124   while(1);
 125 } //no-warning
 126
 127
 128 void f5(void) {
 129   // See "libxtables: move some code to avoid cautions in vfork man page"
 130   // (http://lists.netfilter.org/pipermail/netfilter-buglog/2014-October/003280.html).
 131   if (vfork() == 0) { // expected-warning{{Call to function 'vfork' is insecure}}
 132     execl("prog", "arg1", 0); // no-warning
 133     exit(1);  // expected-warning{{This function call is prohibited after a successful vfork}}
 134   }
 135 }
 136