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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-06-18 20:51:59 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-06-18 20:51:59 +0000 |
| commit | 41d28499a28249549d8f589370348479ff7232af (patch) | |
| tree | 9e2b1219de902ca0967887f6bea05b00cf8390c9 /src | |
| parent | 2b6dd51a5f85e904bc14f7ef00ea89fd003bdf1d (diff) | |
| download | postgresql-41d28499a28249549d8f589370348479ff7232af.tar.gz postgresql-41d28499a28249549d8f589370348479ff7232af.zip | |
When using C-string lookup keys in a dynahash.c hash table, use strncpy()
not memcpy() to copy the offered key into the hash table during HASH_ENTER.
This avoids possible core dump if the passed key is located very near the
end of memory. Per report from Stefan Kaltenbrunner.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/hash/dynahash.c | 12 | ||||
| -rw-r--r-- | src/include/utils/hsearch.h | 4 |
2 files changed, 13 insertions, 3 deletions
diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c index c6f9b023697..ef92103b64a 100644 --- a/src/backend/utils/hash/dynahash.c +++ b/src/backend/utils/hash/dynahash.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/hash/dynahash.c,v 1.48 2003/08/19 01:13:41 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/hash/dynahash.c,v 1.48.2.1 2005/06/18 20:51:59 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -144,6 +144,14 @@ hash_create(const char *tabname, long nelem, HASHCTL *info, int flags) else hashp->match = memcmp; + /* + * Similarly, the key-copying function defaults to strncpy() or memcpy(). + */ + if (hashp->hash == string_hash) + hashp->keycopy = (HashCopyFunc) strncpy; + else + hashp->keycopy = memcpy; + if (flags & HASH_SHARED_MEM) { /* @@ -644,7 +652,7 @@ hash_search(HTAB *hashp, /* copy key into record */ currBucket->hashvalue = hashvalue; - memcpy(ELEMENTKEY(currBucket), keyPtr, hctl->keysize); + hashp->keycopy(ELEMENTKEY(currBucket), keyPtr, hctl->keysize); /* caller is expected to fill the data field on return */ diff --git a/src/include/utils/hsearch.h b/src/include/utils/hsearch.h index 05d26e9a150..d6f43163811 100644 --- a/src/include/utils/hsearch.h +++ b/src/include/utils/hsearch.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: hsearch.h,v 1.29 2003/08/19 01:13:41 tgl Exp $ + * $Id: hsearch.h,v 1.29.2.1 2005/06/18 20:51:59 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -24,6 +24,7 @@ typedef uint32 (*HashValueFunc) (const void *key, Size keysize); typedef int (*HashCompareFunc) (const void *key1, const void *key2, Size keysize); +typedef void *(*HashCopyFunc) (void *dest, const void *src, Size keysize); /* * Space allocation function for a hashtable --- designed to match malloc(). @@ -108,6 +109,7 @@ typedef struct HTAB * used */ char *tabname; /* table name (for error messages) */ bool isshared; /* true if table is in shared memory */ + HashCopyFunc keycopy; /* key copying function */ } HTAB; /* Parameter data structure for hash_create */ |