Memcpy, memmove and memset should be only called on valid pointers ev…

…en when

the size is zero to avoid undefined behavior.


git-svn-id: https://svn.r-project.org/R/trunk@87180 00db46b3-68df-0310-9c12-caf00c1e9a41

src/extra/graphapp/bitmaps.c

@@ -211,7 +211,8 @@ bitmap imagetobitmap(image img)
  data[i+2] = getred(colour);
  }
  }
- else memcpy(data, pixel32, 4*height*width);
+ else if (height && width)
+ memcpy(data, pixel32, 4*height*width);
 
  /* Create the bitmap from the DIB data.
  Could also use CreateDIBsection */

src/extra/xdr/xdr_mem.c

@@ -168,7 +168,7 @@ xdrmem_getbytes(
 
  if ((xdrs->x_handy -= len) < 0)
  return (FALSE);
- memcpy(addr, xdrs->x_private, len);
+ if (len) memcpy(addr, xdrs->x_private, len);
  xdrs->x_private += len;
  return (TRUE);
 }
@@ -182,7 +182,7 @@ xdrmem_putbytes(
 
  if ((xdrs->x_handy -= len) < 0)
  return (FALSE);
- memcpy(xdrs->x_private, addr, len);
+ if (len) memcpy(xdrs->x_private, addr, len);
  xdrs->x_private += len;
  return (TRUE);
 }

src/gnuwin32/console.c

@@ -2000,7 +2000,8 @@ int consolereads(control c, const char *prompt, char *buf, int len,
  segment is empty (should not happen) or
  internal segment of line of same length as buffer */
 
- memcpy(buf, segment, slen);
+ if (slen)
+ memcpy(buf, segment, slen);
  free(segment);
  buf[slen] = '\0';
  return res;

src/gnuwin32/getline/getline.c

@@ -447,9 +447,10 @@ gl_realloc(void *ptr, int olditems, int newitems, size_t itemsize)
  void *res;
  if (!(res = realloc(ptr, newitems * itemsize)))
  gl_error("\n*** Error: getline(): not enough memory.\n");
- memset(((char *)res) + olditems * itemsize,
- 0,
- (newitems - olditems) * itemsize);
+ if (newitems > olditems)
+ memset(((char *)res) + olditems * itemsize,
+ 0,
+ (newitems - olditems) * itemsize);
  return res;
 }
 
@@ -1556,11 +1557,10 @@ hist_save(const char *p)
 {
  char *s = 0;
  int len = strlen(p);
- char *nl = strchr(p, '\n');
 
- if (nl) {
+ if (len && p[len - 1] == '\n') {
  if ((s = (char *) malloc(len)) != 0) {
-  memcpy(s, p, len-1);
+  memcpy(s, p, len-1);
  s[len-1] = 0;
  }
  } else {

src/gnuwin32/system.c

@@ -419,7 +419,8 @@ CharReadConsole(const char *prompt, unsigned char *buf, int len,
  int tocopy = remaining;
  if (tocopy > len - 1) tocopy = len - 1;
 
- memcpy(buf, line + offset, tocopy);
+ if (tocopy)
+ memcpy(buf, line + offset, tocopy);
  buf[tocopy] = '\0';
  remaining -= tocopy;
  offset += tocopy;

src/include/R_ext/RS.h

@@ -48,6 +48,8 @@ extern "C" {
 extern void *R_chk_calloc(R_SIZE_T, R_SIZE_T);
 extern void *R_chk_realloc(void *, R_SIZE_T);
 extern void R_chk_free(void *);
+extern void *R_chk_memcpy(void *, const void *, R_SIZE_T);
+extern void *R_chk_memset(void *, int, R_SIZE_T);
 
 #ifndef STRICT_R_HEADERS
 /* S-PLUS 3.x but not 5.x NULLed the pointer in Free.
@@ -64,10 +66,10 @@ extern void R_chk_free(void *);
 #define R_Free(p) (R_chk_free( (void *)(p) ), (p) = NULL)
 
 /* Nowadays API: undocumented until 4.1.2: widely used. */
-#define Memcpy(p,q,n) memcpy( p, q, (R_SIZE_T)(n) * sizeof(*p) )
+#define Memcpy(p,q,n) R_chk_memcpy( p, q, (R_SIZE_T)(n) * sizeof(*p) )
 
 /* Nowadays API: added for 3.0.0 but undocumented until 4.1.2. */
-#define Memzero(p,n) memset(p, 0, (R_SIZE_T)(n) * sizeof(*p))
+#define Memzero(p,n) R_chk_memset(p, 0, (R_SIZE_T)(n) * sizeof(*p))
 
 /* API: Added in R 2.6.0 */
 #define CallocCharBuf(n) (char *) R_chk_calloc(((R_SIZE_T)(n))+1, sizeof(char))

src/library/graphics/src/stem.c

@@ -180,7 +180,8 @@ C_bincount(double *x, R_xlen_t n, double *breaks, R_xlen_t nb, int *count,
  R_xlen_t i, lo, hi, nb1 = nb - 1, new;
 
  // for(i = 0; i < nb1; i++) count[i] = 0;
- memset(count, 0, nb1 * sizeof(int));
+ if (nb1)
+ memset(count, 0, nb1 * sizeof(int));
 
  for(i = 0 ; i < n ; i++)
  if(R_FINITE(x[i])) { // left in as a precaution

src/library/stats/src/HoltWinters.c

@@ -1,6 +1,6 @@
 /* R : A Computer Language for Statistical Data Analysis
  *
- * Copyright (C) 2003-7 The R Core Team
+ * Copyright (C) 2003-24 The R Core Team
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -54,7 +54,7 @@ void HoltWinters (double *x,
  /* copy start values to the beginning of the vectors */
  level[0] = *a;
  if (*dotrend == 1) trend[0] = *b;
- if (*doseasonal == 1) memcpy(season, s, *period * sizeof(double));
+ if (*doseasonal == 1 && *period) memcpy(season, s, *period * sizeof(double));
 
  for (i = *start_time - 1; i < *xl; i++) {
  /* indices for period i */

src/library/stats/src/ansari.c

@@ -1,6 +1,6 @@
 /*
  * R : A Computer Language for Statistical Data Analysis
- * Copyright (C) 1999-2016 The R Core Team
+ * Copyright (C) 1999-2024 The R Core Team
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -35,10 +35,12 @@ w_init(int m, int n)
  double ***w;
 
  w = (double ***) R_alloc(m + 1, sizeof(double **));
- memset(w, '\0', (m+1) * sizeof(double**));
+ if (m+1)
+ memset(w, '\0', (m+1) * sizeof(double**));
  for (i = 0; i <= m; i++) {
  w[i] = (double**) R_alloc(n + 1, sizeof(double *));
- memset(w[i], '\0', (n+1) * sizeof(double*));
+ if (n+1)
+ memset(w[i], '\0', (n+1) * sizeof(double*));
  }
  return(w);
 }
@@ -57,7 +59,8 @@ cansari(int k, int m, int n, double ***w)
 
  if (w[m][n] == 0) {
  w[m][n] = (double *) R_alloc(u + 1, sizeof(double));
- memset(w[m][n], '\0', (u + 1) * sizeof(double));
+ if (u+1)
+ memset(w[m][n], '\0', (u + 1) * sizeof(double));
  for (i = 0; i <= u; i++)
  w[m][n][i] = -1;
  }

src/library/stats/src/kendall.c

@@ -1,6 +1,6 @@
 /*
  * R : A Computer Language for Statistical Data Analysis
- * Copyright (C) 1999-2016 The R Core Team.
+ * Copyright (C) 1999-2024 The R Core Team.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -40,7 +40,8 @@ ckendall(int k, int n, double **w)
  if ((k < 0) || (k > u)) return(0);
  if (w[n] == 0) {
  w[n] = (double *) R_alloc(u + 1, sizeof(double));
- memset(w[n], '\0', sizeof(double) * (u+1));
+ if (u+1)
+ memset(w[n], '\0', sizeof(double) * (u+1));
  for (i = 0; i <= u; i++) w[n][i] = -1;
  }
  if (w[n][k] < 0) {
@@ -82,7 +83,8 @@ pkendall(int len, double *Q, double *P, int n)
  double **w;
 
  w = (double **) R_alloc(n + 1, sizeof(double *));
- memset(w, '\0', sizeof(double*) * (n+1));
+ if (n+1)
+ memset(w, '\0', sizeof(double*) * (n+1));
 
  for (i = 0; i < len; i++) {
  q = floor(Q[i] + 1e-7);

src/library/stats/src/model.c

@@ -1,6 +1,6 @@
 /*
  * R : A Computer Language for Statistical Data Analysis
- * Copyright (C) 1997--2023 The R Core Team
+ * Copyright (C) 1997--2024 The R Core Team
  * Copyright (C) 1995, 1996 Robert Gentleman and Ross Ihaka
  *
  * This program is free software; you can redistribute it and/or modify
@@ -1274,7 +1274,8 @@ static void ExtractVars(SEXP formula)
 static SEXP AllocTerm(void) // (<global> nwords)
 {
  SEXP term = allocVector(INTSXP, nwords); // caller must PROTECT
- memset(INTEGER(term), 0, nwords * sizeof(int));
+ if (nwords)
+ memset(INTEGER(term), 0, nwords * sizeof(int));
  return term;
 }
 

src/library/stats/src/port.c

@@ -1,6 +1,6 @@
 /*
  * R : A Computer Language for Statistical Data Analysis
- * Copyright (C) 2005-2022 The R Core Team.
+ * Copyright (C) 2005-2024 The R Core Team.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -236,7 +236,8 @@ double F77_NAME(dv2nrm)(int *n, const double x[])
 void F77_NAME(dv7cpy)(int *n, double dest[], const double src[])
 {
  /* Was memcpy, but overlaps seen */
- memmove(dest, src, *n * sizeof(double));
+ if (*n)
+ memmove(dest, src, *n * sizeof(double));
 }
 
 /* dv7ipr... applies forward permutation to vector. */

src/library/stats/src/rWishart.c

@@ -1,6 +1,6 @@
 /*
  * R : A Computer Language for Statistical Data Analysis
- * Copyright (C) 2012-2022 The R Core Team
+ * Copyright (C) 2012-2024 The R Core Team
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -92,7 +92,8 @@ rWishart(SEXP ns, SEXP nuP, SEXP scal)
  scCp = R_Calloc(psqr, double);
 
  Memcpy(scCp, REAL(scal), psqr);
- memset(tmp, 0, psqr * sizeof(double));
+ if (psqr)
+ memset(tmp, 0, psqr * sizeof(double));
  F77_CALL(dpotrf)("U", &(dims[0]), scCp, &(dims[0]), &info FCONE); // LAPACK
  if (info)
  error(_("'scal' matrix is not positive-definite"));

src/library/tools/src/gramRd.c

@@ -3208,7 +3208,8 @@ static SEXP xxusermacro(SEXP macro, SEXP args, YYLTYPE *lloc)
  SEXP stri = CAR(si);
  if (!isComment(stri)) {
  int nc = LENGTH(STRING_ELT(stri, 0));
- memcpy(str + offset, CHAR(STRING_ELT(stri, 0)), nc);
+ if (nc)
+ memcpy(str + offset, CHAR(STRING_ELT(stri, 0)), nc);
  offset += nc;
  }
  }

src/library/tools/src/gramRd.y

@@ -670,7 +670,8 @@ static SEXP xxusermacro(SEXP macro, SEXP args, YYLTYPE *lloc)
  SEXP stri = CAR(si);
  if (!isComment(stri)) {
  int nc = LENGTH(STRING_ELT(stri, 0));
- memcpy(str + offset, CHAR(STRING_ELT(stri, 0)), nc);
+ if (nc)
+ memcpy(str + offset, CHAR(STRING_ELT(stri, 0)), nc);
  offset += nc;
  }
  }

src/main/altclasses.c

@@ -1,6 +1,6 @@
 /*
  * R : A Computer Language for Statistical Data Analysis
- * Copyright (C) 2016--2023 The R Core Team
+ * Copyright (C) 2016--2024 The R Core Team
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -690,7 +690,8 @@ static R_INLINE SEXP ExpandDeferredStringElt(SEXP x, R_xlen_t i)
  if (val == R_NilValue) {
  R_xlen_t n = XLENGTH(x);
  val = allocVector(STRSXP, n);
- memset(STDVEC_DATAPTR(val), 0, n * sizeof(SEXP));
+ if (n)
+ memset(STDVEC_DATAPTR(val), 0, n * sizeof(SEXP));
  SET_DEFERRED_STRING_EXPANDED(x, val);
  }
 

src/main/apply.c

@@ -1,6 +1,6 @@
 /*
  * R : A Computer Language for Statistical Data Analysis
- * Copyright (C) 2000-2023 The R Core Team
+ * Copyright (C) 2000-2024 The R Core Team
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -206,7 +206,7 @@ attribute_hidden SEXP do_vapply(SEXP call, SEXP op, SEXP args, SEXP rho)
  case STRSXP: SET_STRING_ELT(ans, i, STRING_ELT(val, 0)); break;
  case VECSXP: SET_VECTOR_ELT(ans, i, VECTOR_ELT(val, 0)); break;
  }
- } else { // commonLen > 1 (typically, or == 0) :
+ } else if (commonLen) { // commonLen > 1
  switch (commonType) {
  case REALSXP:
  memcpy(REAL(ans) + common_len_offset,