ray@dirac.physics.purdue.edu (Ray Moody) (12/10/89)
Description:
Index (posted to comp.sources.unix in late October) can dump core.
It assumes that memory returned by malloc() and realloc() is zero'ed.
When it isn't, there is a 50-50 chance that the valid bit will be set
on an entry that has character pointers pointing into nowhere.
Repeat-By:
Since malloc() typically returns random stuff, this bug is hard to
repeat. I found that the best way was to run index without any
arguments and select a database that didn't yeat have a .db file
associated with it. Add a new entry, and then try to save the
database.
Fix:
RCS file: /a/ray/src/index/RCS/dbio.c,v
retrieving revision 1.1
retrieving revision 1.1.1.1
diff -c -r1.1 -r1.1.1.1
*** /tmp/,RCSt1a06179 Sat Dec 9 17:25:22 1989
--- /tmp/,RCSt2a06179 Sat Dec 9 17:25:22 1989
***************
*** 1,5 ****
#ifndef lint
! static char *RCSid = "$Header: /a/ray/src/index/RCS/dbio.c,v 1.1 89/08/09 11:06:36 davy Exp $";
#endif
/*
* dbio.c - database input/output routines.
--- 1,5 ----
#ifndef lint
! static char *RCSid = "$Header: /a/ray/src/index/RCS/dbio.c,v 1.1.1.1 89/12/09 17:07:09 ray Exp $";
#endif
/*
* dbio.c - database input/output routines.
***************
*** 12,17 ****
--- 12,20 ----
* davy@riacs.edu
*
* $Log: dbio.c,v $
+ * Revision 1.1.1.1 89/12/09 17:07:09 ray
+ * Fixed core dump.
+ *
* Revision 1.1 89/08/09 11:06:36 davy
* Initial revision
*
***************
*** 117,122 ****
--- 120,126 ----
{
FILE *fp;
register int i;
+ int j;
struct dbfile *malloc(), *realloc();
char buf[BUFSIZ], dbfile[MAXPATHLEN];
***************
*** 133,138 ****
--- 137,150 ----
}
/*
+ * Fixed Sat Dec 9 16:46:05 EST 1989 by Ray (ray@physics.purdue.edu).
+ * Mark all freshely allocated entrys as invalid.
+ */
+ for (j = 0; j < dbsize; j++) {
+ db[j].db_flag = 0;
+ }
+
+ /*
* Construct the name of the file.
*/
sprintf(dbfile, "%s/%s%s", dbasedir, dbname, DBFILE_SUFFIX);
***************
*** 157,162 ****
--- 169,183 ----
if (db == NULL) {
error("%s: out of memory.\n", pname, 0, 0);
exit(1);
+ }
+
+ /*
+ * Fixed Sat Dec 9 16:46:05 EST 1989 by Ray
+ * (ray@physics.purdue.edu). Mark all freshely
+ * allocated entrys as invalid.
+ */
+ for (j = dbentries; j < dbsize; j++) {
+ db[j].db_flag = 0;
}
}