Add overflow-safe allocation wrapper pmem_calloc_safe() (#369)

* Add overflow-safe allocation wrappers to pmem module

* Replace malloc(nmemb*size) with pmem_calloc_safe in high-risk sites

---------

Co-authored-by: Levi Neely <lkn@darkstar.example.net>

pclsync/papi.c

@@ -39,6 +39,7 @@
 #include "psynclib.h"
 #include "ptimer.h"
 #include "pdbg.h"
+#include "pmem.h"
 
 /*
   commented definitions are unused, but kept because they may be
@@ -313,7 +314,7 @@ static binresult *do_parse_result(unsigned char **restrict indata,
     arr = NULL;
     cnt = 0;
     alloc = 128;
-    arr = (binresult **)malloc(sizeof(binresult *) * alloc);
+    arr = (binresult **)pmem_calloc_safe(alloc, sizeof(binresult *));
     if (!arr)
       return NULL;
     while (**indata != RPARAM_END) {
@@ -346,7 +347,7 @@ static binresult *do_parse_result(unsigned char **restrict indata,
     arr = NULL;
     cnt = 0;
     alloc = 32;
-    arr = (struct _hashpair *)malloc(sizeof(struct _hashpair) * alloc);
+    arr = (struct _hashpair *)pmem_calloc_safe(alloc, sizeof(struct _hashpair));
     if (!arr)
       return NULL;
     while (**indata != RPARAM_END) {
@@ -398,10 +399,10 @@ static binresult *parse_result(unsigned char *data, size_t datalen) {
   retlen = calc_ret_len(&datac, &datalenc, &strcnt);
   if (retlen == -1)
     return NULL;
-  datac = malloc(sizeof(unsigned char) * retlen);
+  datac = pmem_calloc_safe(retlen, sizeof(unsigned char));
   if (!datac)
     return NULL;
-  strings = malloc(sizeof(binresult *) * strcnt);
+  strings = pmem_calloc_safe(strcnt, sizeof(binresult *));
   if (!strings) {
     free(datac);
     return NULL;

pclsync/pbusinessaccount.c

@@ -32,6 +32,7 @@
 #include "pnetlibs.h"
 #include "psys.h"
 #include "psql.h"
+#include "pmem.h"
 
 #include <stdio.h>
 
@@ -103,12 +104,18 @@ int do_psync_account_stopshare(psync_shareid_t usershareids[], int nusershareid,
   if (unlikely(numparam == 1))
     return -3;
 
-  t = (binparam *)malloc(numparam * sizeof(binparam));
+  t = (binparam *)pmem_calloc_safe(numparam, sizeof(binparam));
+  if (!t)
+    return -1;
 
   init_param_str(t, "auth", psync_my_auth);
 
   if (nusershareid) {
-    ids1 = (char *)malloc(nusershareid * FOLDERID_ENTRY_SIZE);
+    ids1 = (char *)pmem_calloc_safe(nusershareid, FOLDERID_ENTRY_SIZE);
+    if (!ids1) {
+      free(t);
+      return -1;
+    }
     idsp = ids1;
     for (i = 0; i < nusershareid; ++i) {
       k = sprintf(idsp, "%lld", (long long)usershareids[i]);
@@ -124,7 +131,13 @@ int do_psync_account_stopshare(psync_shareid_t usershareids[], int nusershareid,
   }
 
   if (nteamshareid) {
-    ids2 = (char *)malloc(nteamshareid * FOLDERID_ENTRY_SIZE);
+    ids2 = (char *)pmem_calloc_safe(nteamshareid, FOLDERID_ENTRY_SIZE);
+    if (!ids2) {
+      if (nusershareid)
+        free(ids1);
+      free(t);
+      return -1;
+    }
     idsp = ids2;
     for (i = 0; i < nteamshareid; ++i) {
       k = sprintf(idsp, "%lld", (long long)teamshareids[i]);
@@ -209,14 +222,25 @@ int do_psync_account_modifyshare(psync_shareid_t usrshrids[], uint32_t uperms[],
   if (unlikely(numparam == 1))
     return -3;
 
-  t = (binparam *)malloc(numparam * sizeof(binparam));
+  t = (binparam *)pmem_calloc_safe(numparam, sizeof(binparam));
+  if (!t)
+    return -1;
 
   init_param_str(t, "auth", psync_my_auth);
 
   if (nushid) {
-    ids1 = (char *)malloc(nushid * FOLDERID_ENTRY_SIZE);
+    ids1 = (char *)pmem_calloc_safe(nushid, FOLDERID_ENTRY_SIZE);
+    if (!ids1) {
+      free(t);
+      return -1;
+    }
     idsp = ids1;
-    perms1 = (char *)malloc(nushid * FOLDERID_ENTRY_SIZE);
+    perms1 = (char *)pmem_calloc_safe(nushid, FOLDERID_ENTRY_SIZE);
+    if (!perms1) {
+      free(ids1);
+      free(t);
+      return -1;
+    }
     permsp = perms1;
     for (i = 0; i < nushid; ++i) {
       k = sprintf(idsp, "%lld", (long long)usrshrids[i]);
@@ -241,9 +265,26 @@ int do_psync_account_modifyshare(psync_shareid_t usrshrids[], uint32_t uperms[],
   }
 
   if (ntmshid) {
-    ids2 = (char *)malloc(ntmshid * FOLDERID_ENTRY_SIZE);
+    ids2 = (char *)pmem_calloc_safe(ntmshid, FOLDERID_ENTRY_SIZE);
+    if (!ids2) {
+      if (nushid) {
+        free(perms1);
+        free(ids1);
+      }
+      free(t);
+      return -1;
+    }
     idsp = ids2;
-    perms2 = (char *)malloc(ntmshid * FOLDERID_ENTRY_SIZE);
+    perms2 = (char *)pmem_calloc_safe(ntmshid, FOLDERID_ENTRY_SIZE);
+    if (!perms2) {
+      free(ids2);
+      if (nushid) {
+        free(perms1);
+        free(ids1);
+      }
+      free(t);
+      return -1;
+    }
     permsp = perms2;
 
     for (i = 0; i < ntmshid; ++i) {

pclsync/pmem.c

@@ -1,4 +1,6 @@
 #include <sys/mman.h>
+#include <stdlib.h>
+#include <stdint.h>
 
 #include "pcompiler.h"
 #include "psql.h"
@@ -60,3 +62,10 @@ int pmem_munlock(void *ptr, size_t size) {
 void pmem_reset(void *ptr, size_t size) {
   madvise(ptr, size, MADV_DONTNEED);
 }
+
+void *pmem_calloc_safe(size_t nmemb, size_t size) {
+  if (nmemb != 0 && size > SIZE_MAX / nmemb) {
+    return NULL;
+  }
+  return calloc(nmemb, size);
+}

pclsync/pmem.h

@@ -2,6 +2,7 @@
 #define __PMEM_H
 
 #include <stddef.h>
+#include <stdint.h>
 
 void *pmem_mmap(size_t size);
 void *pmem_mmap_safe(size_t size);
@@ -9,5 +10,6 @@ int pmem_munmap(void *ptr, size_t size);
 int pmem_mlock(void *ptr, size_t size);
 int pmem_munlock(void *ptr, size_t size);
 void pmem_reset(void *ptr, size_t size);
+void *pmem_calloc_safe(size_t nmemb, size_t size);
 
 #endif

pclsync/ptools.c

@@ -50,6 +50,7 @@
 #include "psettings.h"
 #include "psql.h"
 #include "ptools.h"
+#include "pmem.h"
 
 #define PTOOLS_MAX_PARAMS 30
 
@@ -135,7 +136,10 @@ int ptools_create_backend_event(const char *binapi, const char *category,
   paramsLocal[5] = (binparam)PAPI_NUM(EPARAM_TIME, etime);
 
   if (pCnt > 0) {
-    keyParams = (char *)malloc(258 * pCnt);
+    keyParams = (char *)pmem_calloc_safe(pCnt, 258);
+    if (!keyParams) {
+      return -1;
+    }
     keyParams[0] = 0;
 
     for (i = 0; i < pCnt; i++) {
@@ -371,7 +375,10 @@ int ptools_backend_call(const char *binapi, const char *wsPath,
     if (strlen(payloadName) > 0) {
       payload = (binresult *)papi_find_result2(res, payloadName, PARAM_HASH);
 
-      *resData = (binresult *)malloc(payload->length * sizeof(binresult));
+      *resData = (binresult *)pmem_calloc_safe(payload->length, sizeof(binresult));
+      if (!*resData) {
+        return -1;
+      }
       memcpy(*resData, payload, (payload->length * sizeof(binresult)));
     }
   }
@@ -450,7 +457,10 @@ void ptools_send_psyncs_event(const char *binapi, const char *auth) {
   int intRes;
   int syncCnt = 0;
 
-  errMsg = (char *)malloc(1024 * sizeof(char));
+  errMsg = (char *)pmem_calloc_safe(1024, sizeof(char));
+  if (!errMsg) {
+    return;
+  }
   errMsg[0] = 0;
 
   time(&rawtime);