tclenv.c

Bug Summary

File:	d/tclenv.c
Warning:	line 365, column 12 Potential leak of memory pointed to by 's'

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-unknown-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name tclenv.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 2 -fhalf-no-semantic-interposition -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/home/isvv/naviserver/nsd -resource-dir /usr/local/lib/clang/15.0.0 -D _FORTIFY_SOURCE=2 -D NDEBUG -D SYSTEM_MALLOC -I ../include -I /usr/include/tcl8.6 -D HAVE_CONFIG_H -internal-isystem /usr/local/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/11/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -std=c99 -fdebug-compilation-dir=/home/isvv/naviserver/nsd -ferror-limit 19 -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-checker alpha -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-07-23-130959-11103-1 -x c tclenv.c

1/*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://mozilla.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is AOLserver Code and related documentation
* distributed by AOL.
*
* The Initial Developer of the Original Code is America Online,
* Inc. Portions created by AOL are Copyright (C) 1999 America Online,
* Inc. All Rights Reserved.
*
* Alternatively, the contents of this file may be used under the terms
* of the GNU General Public License (the "GPL"), in which case the
* provisions of GPL are applicable instead of those above.  If you wish
* to allow use of your version of this file only under the terms of the
* GPL and not to allow others to use your version of this file under the
* License, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the GPL.
* If you do not delete the provisions above, a recipient may use your
* version of this file under either the License or the GPL.
*/


31/*
* tclenv.c --
*
*      Implements "ns_env".
*/

37#include "nsd.h"

39#ifdef HAVE__NSGETENVIRON
40# include <crt_externs.h>
41#elif !defined(_WIN32)
42extern char **environ;
43#endif

45/*
* Local functions defined in this file.
*/

49static int PutEnv(Tcl_Interp *interp, const char *name, const char *value);

51/*
* Loca variables defined in this file.
*/

55static Ns_Mutex lock = NULL((void*)0);

57
58/*
*----------------------------------------------------------------------
*
* NsInitTclEnv --
*
*      Global initialization for tasks.
*
* Results:
*      None.
*
* Side effects:
*      None.
*
*----------------------------------------------------------------------
*/

74void
75NsInitTclEnv(void)
76{
  static bool_Bool initialized = NS_FALSE0;

  if (!initialized) {
      Ns_MutexInit(&lock);
      Ns_MutexSetName(&lock, "ns:env");
      initialized = NS_TRUE1;
  }
84}
85
86/*
*----------------------------------------------------------------------
*
* Ns_GetEnviron --
*
*      Return the environment vector.
*
* Results:
*      Pointer to environment.
*
* Side effects:
*      None.
*
*----------------------------------------------------------------------
*/

102char **
103Ns_GetEnviron(void)
104{
  char **envp;

107#ifdef HAVE__NSGETENVIRON
  envp = *_NSGetEnviron();
109#else
  envp = environ;
111#endif
  return envp;
113}

115
116/*
*----------------------------------------------------------------------
*
* Ns_CopyEnviron --
*
*      Copy the environment to the given dstring along with
*      an argv vector.
*
* Results:
*      Pointer to dsPtr->string.
*
* Side effects:
*      None.
*
*----------------------------------------------------------------------
*/

133char **
134Ns_CopyEnviron(Ns_DStringTcl_DString *dsPtr)
135{
  char *const*envp;
  int i;

  NS_NONNULL_ASSERT(dsPtr != NULL)((void) (0));

  Ns_MutexLock(&lock);
  envp = Ns_GetEnviron();
  for (i = 0;  envp[i] != NULL((void*)0); ++i) {
      Ns_DStringAppendArg(dsPtr, envp[i]);
  }
  Ns_MutexUnlock(&lock);

  return Ns_DStringAppendArgv(dsPtr);
149}

151
152/*
*----------------------------------------------------------------------
*
* NsTclEnvObjCmd --
*
*      Implements "ns_env".  No attempt is made to avoid the
*      race condition between finding a variable and using it as it is
*      assumed the environment would only be modified, if ever, at
*      startup.
*
* Results:
*      Tcl result.
*
* Side effects:
*      Environment variables may be updated.
*
*----------------------------------------------------------------------
*/

171int
172NsTclEnvObjCmd(ClientData UNUSED(clientData)UNUSED_clientData __attribute__((__unused__)), Tcl_Interp *interp, int objc, Tcl_Obj *const* objv)
173{
  int                      result, opt;
  static const char *const opts[] = {
      "exists", "names", "get", "set", "unset", NULL((void*)0)
  };
  enum {
      IExistsIdx, INamesIdx, IGetIdx, ISetIdx, IUnsetIdx
  };

  if (objc < 2) {
1
Assuming 'objc' is >= 2→
2
←
Taking false branch→
      Tcl_WrongNumArgs(interp, 1, objv, "command ?args ...?");
      result = TCL_ERROR1;

  } else if (Tcl_GetIndexFromObj(interp, objv[1], opts, "command", 0,Tcl_GetIndexFromObjStruct(interp, objv[1], opts, sizeof(char *
), "command", 0, &opt)
3
←
Assuming the condition is false→
4
←
Taking false branch→
                          &opt)Tcl_GetIndexFromObjStruct(interp, objv[1], opts, sizeof(char *
), "command", 0, &opt) != TCL_OK0) {
      result = TCL_ERROR1;

  } else {
      const char  *name, *value;
      char        *const *envp;
      Tcl_Obj     *resultObj;
      int          i;

      result = TCL_OK0;
      Ns_MutexLock(&lock);

      switch (opt) {
5
←
Control jumps to 'case ISetIdx:'  at line 225→
      case IExistsIdx:
          if (objc != 3) {
              Tcl_WrongNumArgs(interp, 2, objv, "name");
              result = TCL_ERROR1;
          } else {
              Tcl_SetObjResult(interp, Tcl_NewBooleanObj((getenv(Tcl_GetString(objv[2])) != NULL) ? 1 : 0)Tcl_NewIntObj(((getenv(Tcl_GetString(objv[2])) != ((void*)0))
 ? 1 : 0)!=0));
          }
          break;

      case INamesIdx:
          envp = Ns_GetEnviron();
          resultObj = Tcl_GetObjResult(interp);
          for (i = 0; envp[i] != NULL((void*)0); ++i) {
              Tcl_Obj *obj;

              name = envp[i];
              value = strchr(name, INTCHAR('=')((int)((unsigned char)(('=')))));
              obj = Tcl_NewStringObj(name, (value != NULL((void*)0)) ? (int)(value - name) : -1);
              if (Tcl_ListObjAppendElement(interp, resultObj, obj) != TCL_OK0) {
                  result = TCL_ERROR1;
                  break;
              }
          }
          break;

      case ISetIdx:
          if (objc != 4) {
6
←
Assuming 'objc' is equal to 4→
7
←
Taking false branch→
              Tcl_WrongNumArgs(interp, 2, objv, "name value");
              result = TCL_ERROR1;

          } else if (PutEnv(interp, Tcl_GetString(objv[2]), Tcl_GetString(objv[3])) != TCL_OK0) {
8
←
Calling 'PutEnv'→
              result = TCL_ERROR1;
          }
          break;

      case IGetIdx:
      case IUnsetIdx:
          if (objc != 3 && objc != 4) {
              Tcl_WrongNumArgs(interp, 2, objv, "?-nocomplain? name");
              result = TCL_ERROR1;

          } else if (objc == 4) {
              const char *arg = Tcl_GetString(objv[2]);

              if (!STREQ(arg, "-nocomplain")(((*(arg)) == (*("-nocomplain"))) && (strcmp((arg),("-nocomplain"
)) == 0))) {
                  Tcl_WrongNumArgs(interp, 2, objv, "?-nocomplain? name");
                  result = TCL_ERROR1;
              }
          }

          if (result == TCL_OK0) {
              name = Tcl_GetString(objv[2]);
              value = getenv(name);
              if (value == NULL((void*)0) && objc != 4) {
                  Ns_TclPrintfResult(interp, "no such environment variable: %s", name);
                  result = TCL_ERROR1;

              } else if ((opt == IUnsetIdx) && (PutEnv(interp, name, NULL((void*)0)) != TCL_OK0)) {
                  result = TCL_ERROR1;

              } else {
                  Tcl_SetObjResult(interp, Tcl_NewStringObj(value, -1));
              }
          }
          break;

      default:
          /* unexpected value */
          assert(opt && 0)((void) (0));
          break;
      }

      Ns_MutexUnlock(&lock);
  }
  return result;
275}

277
278/*
*----------------------------------------------------------------------
*
* PutEnv --
*
*      NsTclEnvObjCmd helper routine to update an environment variable.
*
* Results:
*      TCL_OK or TCL_ERROR.
*
* Side effects:
*      Environment variable is set.
*
*----------------------------------------------------------------------
*/

294static int
295PutEnv(Tcl_Interp *interp, const char *name, const char *value)
296{
  char   *s;
  size_t  len, nameLength, valueLength;
  int     result = TCL_OK0;

301#ifdef HAVE_UNSETENV1
  if (value == NULL((void*)0)) {
9
←
Assuming 'value' is not equal to NULL→
10
←
Taking false branch→
      unsetenv(name);
      return result;
  }
306#endif

  /*
   * In case we have no unsetenv(), we have to deal with the value==NULL
   * case here. If the value is not NULL, valueLength contains the
   * terminating NUL character.
   */
  len = nameLength = strlen(name);
  if (value10.1
'value' is not equal to NULL
 != NULL((void*)0)) {
11
←
Taking true branch→
      valueLength = strlen(value) + 1;
      len += valueLength + 1u;
  } else {
      len += 1u;
      valueLength = 0u;
  }

  /*
   * Use malloc() directly (and not ns_malloc())
   * as putenv() expects.
   */
  s = malloc(len + 1u);
12
←
Memory is allocated→
  if (s == NULL((void*)0)) {
13
←
Assuming 's' is not equal to NULL→
14
←
Taking false branch→
      Ns_TclPrintfResult(interp, "could not allocate memory for new env entry");
      result = TCL_ERROR1;
  } else {

      /*
       * This complication for value == NULL below is needed on
       * some platforms (Solaris) which do not have unsetenv()
       * and are picky if we try to pass a value to putenv not
       * conforming to the "name=value" format.
       *
       * This trick will of course work only for platforms which
       * conform to Single Unix Spec and actually uses the storage
       * passed to putenv() to hold the environ entry.
       * However, there are some libc implementations (notably
       * recent BSDs) that do not obey SUS but copy the presented
       * string. This method fails on such platforms.
       */
      memcpy(s, name, nameLength);
      *(s + nameLength) = '=';

      if (valueLength14.1
'valueLength' is not equal to 0
 != 0u) {
15
←
Taking true branch→
          /*
           * Copy the value including the terminatig NUL character.
           */
          memcpy(s + nameLength + 1, value, valueLength);
      } else {
          *(s + nameLength + 1u) = '\0';
      }

      if (putenv(s) != 0) {
16
←
Assuming the condition is false→
17
←
Taking false branch→
          Ns_TclPrintfResult(interp, "could not put environment entry \"%s\": %s",
                             s, Tcl_PosixError(interp));
          free(s);
          result = TCL_ERROR1;
      }
  }

  return result;
18
←
Potential leak of memory pointed to by 's'
366}

368/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* indent-tabs-mode: nil
* End:
*/