Check for failure of malloc() and realloc() when allocating space for

VFD entries.  On platforms where dereferencing a null pointer doesn't
lead to coredump, it's possible that this omission could have led to
unpleasant behavior like deleting the wrong file.

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 3dd15e45d2fa729fdf5e62dacaaaf163cf224b69..4f3004b47d67500fe3807d324d2fbe808f40ce2d 100644 (file)
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -484,7 +484,8 @@ AllocateVfd(void)
        {
                /* initialize header entry first time through */
                VfdCache = (Vfd *) malloc(sizeof(Vfd));
-               Assert(VfdCache != NULL);
+               if (VfdCache == NULL)
+                       elog(FATAL, "AllocateVfd: no room for VFD array");
                MemSet((char *) &(VfdCache[0]), 0, sizeof(Vfd));
                VfdCache->fd = VFD_CLOSED;
 
@@ -506,17 +507,23 @@ AllocateVfd(void)
                 * However, there's not much point in starting *real* small.
                 */
                Size            newCacheSize = SizeVfdCache * 2;
+               Vfd                *newVfdCache;
 
                if (newCacheSize < 32)
                        newCacheSize = 32;
 
-               VfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
-               Assert(VfdCache != NULL);
+               /*
+                * Be careful not to clobber VfdCache ptr if realloc fails;
+                * we will need it during proc_exit cleanup!
+                */
+               newVfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
+               if (newVfdCache == NULL)
+                       elog(FATAL, "AllocateVfd: no room to enlarge VFD array");
+               VfdCache = newVfdCache;
 
                /*
                 * Initialize the new entries and link them into the free list.
                 */
-
                for (i = SizeVfdCache; i < newCacheSize; i++)
                {
                        MemSet((char *) &(VfdCache[i]), 0, sizeof(Vfd));
@@ -529,7 +536,6 @@ AllocateVfd(void)
                /*
                 * Record the new size
                 */
-
                SizeVfdCache = newCacheSize;
        }
 
@@ -553,6 +559,7 @@ FreeVfd(File file)
                free(vfdP->fileName);
                vfdP->fileName = NULL;
        }
+       vfdP->fdstate = 0x0;
 
        vfdP->nextFree = VfdCache[0].nextFree;
        VfdCache[0].nextFree = file;
@@ -678,7 +685,9 @@ fileNameOpenFile(FileName fileName,
 
        Insert(file);
 
-       vfdP->fileName = malloc(strlen(fileName) + 1);
+       vfdP->fileName = (char *) malloc(strlen(fileName) + 1);
+       if (vfdP->fileName == NULL)
+               elog(FATAL, "fileNameOpenFile: no room to save VFD filename");
        strcpy(vfdP->fileName, fileName);
 
        /* Saved flags are adjusted to be OK for re-opening file */