Author: kp
Date: Fri Apr 6 15:01:45 2018
New Revision: 332101
URL: https://svnweb.freebsd.org/changeset/base/332101
Log:
pf: Improve ioctl validation for DIOCRADDTABLES and DIOCRDELTABLES
The DIOCRADDTABLES and DIOCRDELTABLES ioctls can process a number of
tables at a time, and as such try to allocate <number of tables> *
sizeof(struct pfr_table). This multiplication can overflow. Thanks to
mallocarray() this is not exploitable, but an overflow does panic the
system.
Arbitrarily limit this to 65535 tables. pfctl only ever processes one
table at a time, so it presents no issues there.
MFC after: 1 week
Modified:
head/sys/netpfil/pf/pf_ioctl.c
Modified: head/sys/netpfil/pf/pf_ioctl.c
==============================================================================
--- head/sys/netpfil/pf/pf_ioctl.c Fri Apr 6 13:00:45 2018
(r332100)
+++ head/sys/netpfil/pf/pf_ioctl.c Fri Apr 6 15:01:45 2018
(r332101)
@@ -89,6 +89,8 @@ __FBSDID("$FreeBSD$");
#include <net/altq/altq.h>
#endif
+#define PF_TABLES_MAX_REQUEST 65535 /* Maximum tables per request. */
+
static struct pf_pool *pf_get_pool(char *, u_int32_t, u_int8_t, u_int32_t,
u_int8_t, u_int8_t, u_int8_t);
@@ -2530,13 +2532,15 @@ DIOCCHANGEADDR_error:
error = ENODEV;
break;
}
- totlen = io->pfrio_size * sizeof(struct pfr_table);
- pfrts = mallocarray(io->pfrio_size, sizeof(struct pfr_table),
- M_TEMP, M_WAITOK);
- if (! pfrts) {
+
+ if (io->pfrio_size < 0 || io->pfrio_size >
PF_TABLES_MAX_REQUEST) {
error = ENOMEM;
break;
}
+
+ totlen = io->pfrio_size * sizeof(struct pfr_table);
+ pfrts = mallocarray(io->pfrio_size, sizeof(struct pfr_table),
+ M_TEMP, M_WAITOK);
error = copyin(io->pfrio_buffer, pfrts, totlen);
if (error) {
free(pfrts, M_TEMP);
@@ -2559,13 +2563,15 @@ DIOCCHANGEADDR_error:
error = ENODEV;
break;
}
- totlen = io->pfrio_size * sizeof(struct pfr_table);
- pfrts = mallocarray(io->pfrio_size, sizeof(struct pfr_table),
- M_TEMP, M_WAITOK);
- if (! pfrts) {
+
+ if (io->pfrio_size < 0 || io->pfrio_size >
PF_TABLES_MAX_REQUEST) {
error = ENOMEM;
break;
}
+
+ totlen = io->pfrio_size * sizeof(struct pfr_table);
+ pfrts = mallocarray(io->pfrio_size, sizeof(struct pfr_table),
+ M_TEMP, M_WAITOK);
error = copyin(io->pfrio_buffer, pfrts, totlen);
if (error) {
free(pfrts, M_TEMP);
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