39476 - SECKEY_OpenKeyDB inconsistent in freeing memory

Status: VERIFIED FIXED

(NSS :: Libraries, defect, P3)

Description

[Fred Roeber]

This is a replacement for the internal Netscape bug
http://scopus/bugsplat/show_bug.cgi?id=299899 .

If I call SECKEY_OpenKeyDBFilename, a pointer to the filename is passed. 
OpenKeyDB frees this filename.  It is not expected behaviour for an input
parameter to be freed like this.  If you are creating a new database, OpenKeyDB
then calls the dbname callback again, which this time returns an empty string
(PORT_Free zeroes the memory?).  The rest of the function is operating on the
wrong file, which causes havoc.  Specifically, the global salt value isn't
getting set properly.

------- Additional Comments From relyea  07/08/98 10:42 ------- 

I'm pretty sure this is how the key stuff was supposed to work. I'll assign
it to someone who cares and let them work on it as part of the SDK cleanup

------- Additional Comments From nicolson  07/08/98 11:35 ------- 

The bug might not be in OpenKeyDB, it could be in the interface between
OpenKeyDB and OpenKeyDBFilename.  But the bottom line is that OpenKeyDBFilename
doesn't work if the key database doesn't exist yet and has to be created.

------- Additional Comments From nicolson  08/26/98 23:34 ------- 

Sorry, but this really is a bug.  Anyone who uses SECKEY_OpenKeyDBFilename is
going to have an error that is very difficult to track down.  Later in their
code they will SEGV because their global salt has been corrupted.  If they stop
in SECKEY_OpenKeyDB and examine the salt, it's fine.  This needs to be fixed
before more people shoot themselves in the foot.

I'm labeling it CRITICAL because it causes a SEGV. This will happen when you use
OpenKeyDBFilename if the file doesn't already exist.

------- Additional Comments From nicolson  08/26/98 23:41 ------- 

Actually, the fix for this is trivial: change keyDBFilenameCallback in keydb.c
to return PORT_strdup((char*)arg) instead of just (char*)arg.

------- Additional Comments From nicolson  09/16/98 16:45 ------- 

The exact same bug (and solution) applies to CERT_OpenCertDBFilename.  I just
blew several hours tracking down mysterious memory corruption to discover this. 
Please fix it soon.

Comment 1

[John G. Myers]

OpenKeyDB needs to either always free the string returned by the callback or 
never free it.  It should not be freeing the string only in the error case--this 
causes a memory leak in the success case.

Comment 2

[John G. Myers]

*** Bug 39481 has been marked as a duplicate of this bug. ***

Comment 3

[John G. Myers]

Attachment: proposed fix 1

Comment 4

[John G. Myers]

Assign to nelsonb for review.

CERT_OpenCertDB(), on the other hand, always leaks the filename.  It should
probably be changed to match SECKEY_OpenKeyDB(), but that's a different bug.

Comment 5

[John G. Myers]

The CERT_OpenCertDB() issue is bug 49477.

Comment 6

[Nelson Bolyard (seldom reads bugmail)]

This bug shold be assigned to either relyea or thayes.
I nominate Terry.

Comment 7

[Terry Hayes]

Suggested patch applied to keydb.c

Comment 8

[Wan-Teh Chang]

I found that the second half of jgmyers' patch
was not applied.  I just applied it and verified
that all of the patch has been checked in.
/cvsroot/mozilla/security/nss/lib/softoken/keydb.c, revisions 1.2,1.3