X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fsrc%2Fstore.c;h=8603a8fb11e568cef40de7e2b659e32554333c30;hb=dd09071d45761ca63f50e60eff5eed4f8e063a74;hp=c664ad9f42060dd95cb4baa5f8a8fc00f5b100d6;hpb=410b935d8ed35762b76b0edfa7a9fb9ba6500ebd;p=user%2Fhenk%2Fcode%2Fexim.git

diff --git a/src/src/store.c b/src/src/store.c
index c664ad9f4..8603a8fb1 100644
--- a/src/src/store.c
+++ b/src/src/store.c
@@ -3,7 +3,7 @@
 *************************************************/
 
 /* Copyright (c) University of Cambridge 1995 - 2018 */
-/* Copyright (c) The Exim maintainers 2019 - 2020 */
+/* Copyright (c) The Exim maintainers 2019 - 2021 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Exim gets and frees all its store through these functions. In the original
@@ -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,
@@ -165,28 +168,31 @@ 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",
 };
 #endif
 
 
-static void * internal_store_malloc(int, const char *, int);
+static void * internal_store_malloc(size_t, const char *, int);
 static void   internal_store_free(void *, const char *, int linenumber);
 
 /******************************************************************************/
@@ -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        *
 *************************************************/
@@ -264,20 +283,20 @@ Returns:      pointer to store (panic on malloc failure)
 */
 
 void *
-store_get_3(int size, BOOL tainted, const char *func, int linenumber)
+store_get_3(int size, BOOL tainted, const char * func, int linenumber)
 {
 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 +343,21 @@ 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);
+      int err = posix_memalign((void **)&newblock,
+				pgsize, (mlength + pgsize - 1) & ~(pgsize - 1));
+      if (err)
+	log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+	  "failed to alloc (using posix_memalign) %d bytes of memory: '%s'"
+	  "called from line %d in %s",
+	  size, strerror(err), linenumber, func);
+      }
+    else
+#endif
+      newblock = internal_store_malloc(mlength, func, linenumber);
     newblock->next = NULL;
     newblock->length = length;
 #ifndef RESTRICTED_MEMORY
@@ -385,9 +418,9 @@ Returns:      pointer to store (panic on malloc failure)
 */
 
 void *
-store_get_perm_3(int size, BOOL tainted, const char *func, int linenumber)
+store_get_perm_3(int size, BOOL tainted, const char * func, int linenumber)
 {
-void *yield;
+void * yield;
 int old_pool = store_pool;
 store_pool = POOL_PERM;
 yield = store_get_3(size, tainted, func, linenumber);
@@ -428,12 +461,10 @@ 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 +516,8 @@ 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 +595,8 @@ 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 +611,8 @@ 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 +836,11 @@ 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);
@@ -828,21 +867,29 @@ Returns:      pointer to gotten store (panic on failure)
 */
 
 static void *
-internal_store_malloc(int size, const char *func, int line)
+internal_store_malloc(size_t size, const char *func, int line)
 {
 void * yield;
 
-size += sizeof(int);	/* space to store the size, used under debug */
+/* Check specifically for a possibly result of conversion from
+a negative int, to the (unsigned, wider) size_t */
+
+if (size >= INT_MAX/2)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+            "bad memory allocation requested (" SIZE_T_FMT " bytes) at %s %d",
+            size, func, line);
+
+size += sizeof(size_t);	/* space to store the size, used under debug */
 if (size < 16) size = 16;
 
-if (!(yield = malloc((size_t)size)))
-  log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to malloc %d bytes of memory: "
+if (!(yield = malloc(size)))
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to malloc " SIZE_T_FMT " bytes of memory: "
     "called from line %d in %s", size, line, func);
 
 #ifndef COMPILE_UTILITY
-DEBUG(D_any) *(int *)yield = size;
+DEBUG(D_any) *(size_t *)yield = size;
 #endif
-yield = US yield + sizeof(int);
+yield = US yield + sizeof(size_t);
 
 if ((nonpool_malloc += size) > max_nonpool_malloc)
   max_nonpool_malloc = nonpool_malloc;
@@ -855,8 +902,8 @@ giving warnings. */
 is not filled with zeros so as to catch problems. */
 
 if (f.running_in_test_harness)
-  memset(yield, 0xF0, (size_t)size - sizeof(int));
-DEBUG(D_memory) debug_printf("--Malloc %6p %5d bytes\t%-20s %4d\tpool %5d  nonpool %5d\n",
+  memset(yield, 0xF0, size - sizeof(size_t));
+DEBUG(D_memory) debug_printf("--Malloc %6p %5lu bytes\t%-20s %4d\tpool %5d  nonpool %5d\n",
   yield, size, func, line, pool_malloc, nonpool_malloc);
 #endif  /* COMPILE_UTILITY */
 
@@ -864,7 +911,7 @@ return yield;
 }
 
 void *
-store_malloc_3(int size, const char *func, int linenumber)
+store_malloc_3(size_t size, const char *func, int linenumber)
 {
 if (n_nonpool_blocks++ > max_nonpool_blocks)
   max_nonpool_blocks = n_nonpool_blocks;
@@ -889,10 +936,11 @@ Returns:      nothing
 static void
 internal_store_free(void * block, const char * func, int linenumber)
 {
-uschar * p = US block - sizeof(int);
+uschar * p = US block - sizeof(size_t);
 #ifndef COMPILE_UTILITY
-DEBUG(D_any) nonpool_malloc -= *(int *)p;
-DEBUG(D_memory) debug_printf("----Free %6p %5d bytes\t%-20s %4d\n", block, *(int *)p, func, linenumber);
+DEBUG(D_any) nonpool_malloc -= *(size_t *)p;
+DEBUG(D_memory) debug_printf("----Free %6p %5ld bytes\t%-20s %4d\n",
+		    block, *(size_t *)p, func, linenumber);
 #endif
 free(p);
 }