Bug 1255710 (CVE-2015-5221)

A use-after-free which leads to double-free vulnerability was found in Jasper JPEG-2000 library, in src/libjasper/mif/mif_cod.c file.

    553                 case MIF_HSAMP:
    554                         cmpt->sampperx = atoi(jas_tvparser_getval(tvp));
    555                         break;
    556                 case MIF_VSAMP:
    557                         cmpt->samppery = atoi(jas_tvparser_getval(tvp));
    558                         break;

    572         jas_tvparser_destroy(tvp);
    573         if (!cmpt->sampperx || !cmpt->samppery) {
    574                 goto error;
    575         }
    576         if (mif_hdr_addcmpt(hdr, hdr->numcmpts, cmpt)) {
    577                 goto error;
    578         }
    579         return 0;
    580
    581 error:
    582         if (cmpt) {
    583                 mif_cmpt_destroy(cmpt);
    584         }
    585         if (tvp) {
    586                 jas_tvparser_destroy(tvp);
    587         }
    588         return -1;

Both tvp and tvp->buf are freed by jas_tvparser_destroy(tvp), but if one of the two following branch conditions is taken, a second call to jas_tvparser_destroy(tvp) occurs. It is a use-after-free because before calling free in jas_tvparser_destroy there is a check to tvp->buf, while tvp could have been freed. Two double free take place just after this check (on tvp->buf and tvp).

Public via:

http://seclists.org/oss-sec/2015/q3/408

Acknowledgements:

Name: Josselin Feist