X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/410b935d8ed35762b76b0edfa7a9fb9ba6500ebd..fbe8578a39505c146223ffcf2c63a5ba8bb0d9a4:/src/src/store.c

diff --git a/src/src/store.c b/src/src/store.c
index c664ad9f4..e8819e3e3 100644
--- a/src/src/store.c
+++ b/src/src/store.c
@@ -41,6 +41,9 @@ The following different types of store are recognized:
   a single message transaction but needed for longer than the use of the main
   pool permits.  Currently this means only receive-time DKIM information.
 
+- There is a dedicated pool for configuration data read from the config file(s).
+  Once complete, it is made readonly.
+
 . Orthogonal to the three pool types, there are two classes of memory: untainted
   and tainted.  The latter is used for values derived from untrusted input, and
   the string-expansion mechanism refuses to operate on such values (obviously,
@@ -165,21 +168,24 @@ static int max_nonpool_malloc;	/* max value for nonpool_malloc */
 static const uschar * pooluse[NPOOLS] = {
 [POOL_MAIN] =		US"main",
 [POOL_PERM] =		US"perm",
+[POOL_CONFIG] =		US"config",
 [POOL_SEARCH] =		US"search",
 [POOL_MESSAGE] =	US"message",
 [POOL_TAINT_MAIN] =	US"main",
 [POOL_TAINT_PERM] =	US"perm",
-[POOL_TAINT_SEARCH] =	US"search",
+[POOL_TAINT_CONFIG] =	US"config",
 [POOL_TAINT_SEARCH] =	US"search",
 [POOL_TAINT_MESSAGE] =	US"message",
 };
 static const uschar * poolclass[NPOOLS] = {
 [POOL_MAIN] =		US"untainted",
 [POOL_PERM] =		US"untainted",
+[POOL_CONFIG] =		US"untainted",
 [POOL_SEARCH] =		US"untainted",
 [POOL_MESSAGE] =	US"untainted",
 [POOL_TAINT_MAIN] =	US"tainted",
 [POOL_TAINT_PERM] =	US"tainted",
+[POOL_TAINT_CONFIG] =	US"tainted",
 [POOL_TAINT_SEARCH] =	US"tainted",
 [POOL_TAINT_MESSAGE] =	US"tainted",
 };
@@ -245,6 +251,19 @@ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Taint mismatch, %s: %s %d\n",
 
 
 
+/******************************************************************************/
+void
+store_writeprotect(int pool)
+{
+#if !defined(COMPILE_UTILITY) && !defined(MISSING_POSIX_MEMALIGN)
+for (storeblock * b = chainbase[pool]; b; b = b->next)
+  if (mprotect(b, ALIGNED_SIZEOF_STOREBLOCK + b->length, PROT_READ) != 0)
+    DEBUG(D_any) debug_printf("config block mprotect: (%d) %s\n", errno, strerror(errno));
+#endif
+}
+
+/******************************************************************************/
+
 /*************************************************
 *       Get a block from the current pool        *
 *************************************************/
@@ -270,14 +289,14 @@ int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
 
 /* Ensure we've been asked to allocate memory.
 A negative size is a sign of a security problem.
-A zero size is also suspect (but we might have to allow it if we find our API
-expects it in some places). */
-if (size < 1)
-  {
+A zero size might be also suspect, but our internal usage deliberately
+does this to return a current watermark value for a later release of
+allocated store. */
+
+if (size < 0 || size >= INT_MAX/2)
   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
             "bad memory allocation requested (%d bytes) at %s %d",
             size, func, linenumber);
-  }
 
 /* Round up the size to a multiple of the alignment. Although this looks a
 messy statement, because "alignment" is a constant expression, the compiler can
@@ -324,7 +343,15 @@ if (size > yield_length[pool])
     if (++nblocks[pool] > maxblocks[pool])
       maxblocks[pool] = nblocks[pool];
 
-    newblock = internal_store_malloc(mlength, func, linenumber);
+#ifndef MISSING_POSIX_MEMALIGN
+    if (pool == POOL_CONFIG)
+      {
+      long pgsize = sysconf(_SC_PAGESIZE);
+      posix_memalign((void **)&newblock, pgsize, (mlength + pgsize - 1) & ~(pgsize - 1));
+      }
+    else
+#endif
+      newblock = internal_store_malloc(mlength, func, linenumber);
     newblock->next = NULL;
     newblock->length = length;
 #ifndef RESTRICTED_MEMORY
@@ -428,12 +455,10 @@ int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
 int inc = newsize - oldsize;
 int rounded_oldsize = oldsize;
 
-if (newsize < 0)
-  {
+if (oldsize < 0 || newsize < oldsize || newsize >= INT_MAX/2)
   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
             "bad memory extension requested (%d -> %d bytes) at %s %d",
             oldsize, newsize, func, linenumber);
-  }
 
 /* Check that the block being extended was already of the required taint status;
 refuse to extend if not. */
@@ -485,7 +510,8 @@ not call with a pointer returned by store_get().  Both the untainted and tainted
 pools corresposding to store_pool are reset.
 
 Arguments:
-  r           place to back up to
+  ptr         place to back up to
+  pool	      pool holding the pointer
   func        function from which called
   linenumber  line number in source file
 
@@ -563,7 +589,8 @@ if (  yield_length[pool] < STOREPOOL_MIN_SIZE
   }
 
 bb = b->next;
-b->next = NULL;
+if (pool != POOL_CONFIG)
+  b->next = NULL;
 
 while ((b = bb))
   {
@@ -578,7 +605,8 @@ while ((b = bb))
   nbytes[pool] -= siz;
   pool_malloc -= siz;
   nblocks[pool]--;
-  internal_store_free(b, func, linenumber);
+  if (pool != POOL_CONFIG)
+    internal_store_free(b, func, linenumber);
 
 #ifndef RESTRICTED_MEMORY
   if (store_block_order[pool] > 13) store_block_order[pool]--;
@@ -802,6 +830,11 @@ if (is_tainted(block) != tainted)
   die_tainted(US"store_newblock", CUS func, linenumber);
 #endif
 
+if (len < 0 || len > newsize)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+            "bad memory extension requested (%d -> %d bytes) at %s %d",
+            len, newsize, func, linenumber);
+
 newtext = store_get(newsize, tainted);
 memcpy(newtext, block, len);
 if (release_ok) store_release_3(block, pool, func, linenumber);
@@ -832,6 +865,11 @@ internal_store_malloc(int size, const char *func, int line)
 {
 void * yield;
 
+if (size < 0 || size >= INT_MAX/2)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+            "bad memory allocation requested (%d bytes) at %s %d",
+            size, func, line);
+
 size += sizeof(int);	/* space to store the size, used under debug */
 if (size < 16) size = 16;