Taint: slow-mode checking only

[users/jgh/exim.git] / src / src / store.c

diff --git a/src/src/store.c b/src/src/store.c
index b65649f4aad1db3c55d976b5f55c09e295554b9d..8e776568a54fbf9511fd011292f003a20ae6bbc2 100644 (file)
--- a/src/src/store.c
+++ b/src/src/store.c
@@ -62,9 +62,11 @@ The following different types of store are recognized:
   recopy a string being built into a tainted allocation if it meets a %s for a
   tainted argument.  Any intermediate-layer function that (can) return a new
   allocation should behave this way; returning a tainted result if any tainted
-  content is used.  Users of functions that modify existing allocations should
-  check if a tainted source and an untainted destination is used, and fail instead
-  (sprintf() being the classic case).
+  content is used.  Intermediate-layer functions (eg. Ustrncpy) that modify
+  existing allocations fail if tainted data is written into an untainted area.
+  Users of functions that modify existing allocations should check if a tainted
+  source and an untainted destination is used, and fail instead (sprintf() being
+  the classic case).
 */
 
 
@@ -124,13 +126,6 @@ static storeblock *current_block[NPOOLS];
 static void *next_yield[NPOOLS];
 static int yield_length[NPOOLS] = { -1, -1, -1,  -1, -1, -1 };
 
-/* The limits of the tainted pools.  Tracking these on new allocations enables
-a fast is_tainted implementation. We assume the kernel only allocates mmaps using
-one side or the other of data+heap, not both. */
-
-void * tainted_base = (void *)-1;
-void * tainted_top = (void *)0;
-
 /* pool_malloc holds the amount of memory used by the store pools; this goes up
 and down as store is reset or released. nonpool_malloc is the total got by
 malloc from other calls; this doesn't go down because it is just freed by
@@ -184,7 +179,6 @@ static void   internal_tainted_free(storeblock *, const char *, int linenumber);
 
 /******************************************************************************/
 
-#ifndef TAINT_CHECK_FAST
 /* Test if a pointer refers to tainted memory.
 
 Slower version check, for use when platform intermixes malloc and mmap area
@@ -198,24 +192,22 @@ BOOL
 is_tainted_fn(const void * p)
 {
 storeblock * b;
-int pool;
 
-for (pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
+for (int pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
   if ((b = current_block[pool]))
     {
-    char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
-    if (CS p >= bc && CS p <= bc + b->length) return TRUE;
+    uschar * bc = US b + ALIGNED_SIZEOF_STOREBLOCK;
+    if (US p >= bc && US p <= bc + b->length) return TRUE;
     }
 
-for (pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
+for (int pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
   for (b = chainbase[pool]; b; b = b->next)
     {
-    char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
-    if (CS p >= bc && CS p <= bc + b->length) return TRUE;
+    uschar * bc = US b + ALIGNED_SIZEOF_STOREBLOCK;
+    if (US p >= bc && US p <= bc + b->length) return TRUE;
     }
 return FALSE;
 }
-#endif
 
 
 void
@@ -226,6 +218,7 @@ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Taint mismatch, %s: %s %d\n",
 }
 
 
+
 /*************************************************
 *       Get a block from the current pool        *
 *************************************************/
@@ -758,7 +751,7 @@ int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
 BOOL release_ok = !tainted && store_last_get[pool] == block;
 uschar * newtext;
 
-#ifndef MACRO_PREDEF
+#if !defined(MACRO_PREDEF) && !defined(COMPILE_UTILITY)
 if (is_tainted(block) != tainted)
   die_tainted(US"store_newblock", CUS func, linenumber);
 #endif
@@ -815,9 +808,6 @@ if (!(yield = mmap(NULL, (size_t)size,
   log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to mmap %d bytes of memory: "
     "called from line %d of %s", size, line, func);
 
-if (yield < tainted_base) tainted_base = yield;
-if ((top = US yield + size) > tainted_top) tainted_top = top;
-
 return store_alloc_tail(yield, size, func, line, US"Mmap");
 }