Date: Tue, 18 Feb 2003 04:41:12 +0100 (CET) From: Maxlor <mail@maxlor.com> To: FreeBSD-gnats-submit@FreeBSD.org Subject: ports/48406: missing initialization bug in /usr/ports/devel/libhash Message-ID: <20030218034112.A7E5012CCE0@maxlor.mine.nu>
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>Number: 48406
>Category: ports
>Synopsis: missing initialization bug in /usr/ports/devel/libhash
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-ports-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Mon Feb 17 19:50:02 PST 2003
>Closed-Date:
>Last-Modified:
>Originator: Maxlor
>Release: FreeBSD 5.0-RELEASE-p1 i386
>Organization:
>Environment:
System: FreeBSD merlin 5.0-RELEASE-p1 FreeBSD 5.0-RELEASE-p1 #0: Sun Feb 16 04:23:52 CET 2003 maxlor@merlin:/usr/obj/usr/src/sys/MERLIN i386
>Description:
The function hash_hash_string in hash.c uses the variable
"u_int32_t hash_value", but does not initialize it before
it is read for the first time. Therefore the function is
broken and yields random results.
>How-To-Repeat:
The code below needs to be compiled as follows:
gcc -g -I/usr/local/include -L/usr/local/lib -o hashtest_str hashtest_str.c -lhash
When run with the corrected libhash, it will store a value
into a hash using a string key, then retrieve it, then list
all keys in the hash (and therefore retrieve it a second time).
When run with a broken libhash, it will either not be able
to retrieve the value, or the retrieved key will be random.
----- CODE START -----
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <hash.h>
#include <dirent.h>
#include <errno.h>
#define NUMBEROFBUCKETS 40000
int main(int argc, char *argv[]) {
hash h;
struct hash_iterator it;
char key[] = "abcd";
int value = 101;
char **pkey;
int *pvalue;
int i;
pkey = malloc(sizeof(char *));
if (pkey == NULL) {
printf("malloc 1 failed\n");
exit(1);
}
pvalue = malloc(sizeof(int));
if (pvalue == NULL) {
printf("malloc 2 failed\n");
exit(1);
}
*pvalue = 0;
printf("Errors: \n");
printf(" %i = ENOENT = key doesn't exist\n", ENOENT);
printf(" %i = ENOMEM = no memory\n", ENOMEM);
if (! hash_initialise(&h, NUMBEROFBUCKETS, hash_hash_string,
hash_compare_string, hash_copy_string,
free, free)) {
printf("Error: initialise\n");
exit(1);
}
printf("Trying to insert key into hash:\n");
if (! hash_insert(&h, key, (void*)value)) {
printf(" Error: insert\n");
exit(1);
} else {
printf(" Inserted: key = %s, value = %i\n", key, value);
}
printf("\n");
printf("Trying to retrieve the same key from hash:\n");
if (! hash_retrieve(&h, key, (void**)pvalue)) {
printf(" Error: retrieve (%i)\n", errno);
//exit(1);
} else {
printf(" Retrieve: key = %s, value = %i\n", key, *pvalue);
}
printf("\n");
if (!hash_iterator_initialise(&h, &it)) {
fprintf(stderr, "Error: hash_iterator_initialise failed\n");
return 1;
}
printf("Iterating through all keys in hash:\n");
while (hash_fetch_next(&h, &it, (void **)pkey, (void**) pvalue)) {
if (! hash_retrieve(&h, *pkey, (void**)pvalue)) {
printf(" Error: retrieve (%i)\n", errno);
} else {
printf(" Retrieve: key = %s, value = %i\n", key, *pvalu
e);
}
}
printf("\nDone\n");
if (!hash_iterator_deinitialise(&h, &it)) {
fprintf(stderr, "Error: hash_iterator_deinitialise failed\n");
return 1;
}
return 0;
}
----- CODE END -----
> Fix:
----- DIFF START -----
sh.c.orig Wed Feb 12 04:38:58 2003
--- hash.c Mon Feb 17 17:03:20 2003
*************** int hash_compare_int(void *key1, void *k
*** 25,31 ****
}
u_int32_t hash_hash_string(void *key, u_int32_t number_of_buckets) {
! u_int32_t hash_value;
while (*(char *)key != '\0') {
hash_value += *(char *)key;
--- 25,31 ----
}
u_int32_t hash_hash_string(void *key, u_int32_t number_of_buckets) {
! u_int32_t hash_value = 0;
while (*(char *)key != '\0') {
hash_value += *(char *)key;
----- DIFF END -----
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
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