bin/137484: Integer overflow in wpa_supplicant base64 encoder

[Jonathan Bokovza]

>Number:         137484
>Category:       bin
>Synopsis:       Integer overflow in wpa_supplicant base64 encoder
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Aug 06 12:00:18 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Jonathan Bokovza
>Release:        7.2
>Organization:
Afarsec
>Environment:
FreeBSD hmmm.mmmm.com 7.2-STABLE FreeBSD 7.2-STABLE #24: Fri Jun 12 16:21:06 IDT 2009     root at hmmmm.mmmm.com:/usr/obj/usr/src/sys/KERN  i386
>Description:
from src/contrib/wpa_supplicant/base64.c :

unsigned char * base64_encode(const unsigned char *src, size_t len,
                              size_t *out_len)
{
        unsigned char *out, *pos;
        const unsigned char *end, *in;
        size_t olen;
        int line_len;

        olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */
        olen += olen / 72; /* line feeds */
        olen++; /* nul termination */
        out = os_malloc(olen);
        if (out == NULL)
                return NULL;


If len is large enough then olen will wrap and malloc will allocate too little memory. This might be a security issue.

>How-To-Repeat:
N/A
>Fix:
        olen++; /* nul termination */
        if (olen < len)
                return NULL;
        out = os_malloc(olen);
        if (out == NULL)
                return NULL;


>Release-Note:
>Audit-Trail:
>Unformatted: