.. what's capping totlen so one doesn't run out of memory?
-a On 24 February 2016 at 23:33, Kristof Provost <[email protected]> wrote: > Author: kp > Date: Thu Feb 25 07:33:59 2016 > New Revision: 296025 > URL: https://svnweb.freebsd.org/changeset/base/296025 > > Log: > pf: Fix possible out-of-bounds write > > In the DIOCRSETADDRS ioctl() handler we allocate a table for struct > pfr_addrs, > which is processed in pfr_set_addrs(). At the users request we also provide > feedback on the deleted addresses, by storing them after the new list > ('bcopy(&ad, addr + size + i, sizeof(ad));' in pfr_set_addrs()). > > This means we write outside the bounds of the buffer we've just allocated. > We need to look at pfrio_size2 instead (i.e. the size the user reserved for > our > feedback). That'd allow a malicious user to specify a smaller pfrio_size2 > than > pfrio_size though, in which case we'd still read outside of the allocated > buffer. Instead we allocate the largest of the two values. > > Reported By: Paul J Murphy <[email protected]> > PR: 207463 > MFC after: 5 days > Differential Revision: https://reviews.freebsd.org/D5426 > > Modified: > head/sys/netpfil/pf/pf_ioctl.c > > Modified: head/sys/netpfil/pf/pf_ioctl.c > ============================================================================== > --- head/sys/netpfil/pf/pf_ioctl.c Thu Feb 25 07:03:10 2016 > (r296024) > +++ head/sys/netpfil/pf/pf_ioctl.c Thu Feb 25 07:33:59 2016 > (r296025) > @@ -2718,13 +2718,14 @@ DIOCCHANGEADDR_error: > case DIOCRSETADDRS: { > struct pfioc_table *io = (struct pfioc_table *)addr; > struct pfr_addr *pfras; > - size_t totlen; > + size_t totlen, count; > > if (io->pfrio_esize != sizeof(struct pfr_addr)) { > error = ENODEV; > break; > } > - totlen = io->pfrio_size * sizeof(struct pfr_addr); > + count = max(io->pfrio_size, io->pfrio_size2); > + totlen = count * sizeof(struct pfr_addr); > pfras = malloc(totlen, M_TEMP, M_WAITOK); > error = copyin(io->pfrio_buffer, pfras, totlen); > if (error) { > _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
