upstream/opnsense-src
1
0
Fork 0
mirror of https://github.com/opnsense/src.git synced 2026-06-08 16:22:46 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Fix bugs in plugable CC algorithm and siftr sysctls.

Browse source 
Use the sysctl_handle_int() handler to write out the old value and read
the new value into a temporary variable. Use the temporary variable
for any checks of values rather than using the CAST_PTR_INT() macro on
req->newptr. The prior usage read directly from userspace memory if the
sysctl() was called correctly. This is unsafe and doesn't work at all on
some architectures (at least i386.)

In some cases, the code could also be tricked into reading from kernel
memory and leaking limited information about the contents or crashing
the system. This was true for CDG, newreno, and siftr on all platforms
and true for i386 in all cases. The impact of this bug is largest in
VIMAGE jails which have been configured to allow writing to these
sysctls.

Per discussion with the security officer, we will not be issuing an
advisory for this issue as root access and a non-default config are
required to be impacted.

Reviewed by:	markj, bz
Discussed with:	gordon (security officer)
MFC after:	3 days
Security:	kernel information leak, local DoS (both require root)
Differential Revision:	https://reviews.freebsd.org/D18443
This commit is contained in:
Brooks Davis 2018-12-15 15:06:22 +00:00
parent 3c3e1b0a98
commit 855acb84ca
7 changed files with 57 additions and 55 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

31
sys/netinet/cc/cc_cdg.c
View file

@ -80,8 +80,6 @@ __FBSDID("$FreeBSD$");
#define CDG_VERSION "0.1"
#define CAST_PTR_INT(X) (*((int*)(X)))
/* Private delay-gradient induced congestion control signal. */
#define CC_CDG_DELAY 0x01000000
@ -358,22 +356,37 @@ cdg_cb_destroy(struct cc_var *ccv)
static int
cdg_beta_handler(SYSCTL_HANDLER_ARGS)
{
int error;
uint32_t new;
if (req->newptr != NULL &&
(CAST_PTR_INT(req->newptr) == 0 || CAST_PTR_INT(req->newptr) > 100))
return (EINVAL);
new = *(uint32_t *)arg1;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (new == 0 || new > 100)
error = EINVAL;
else
*(uint32_t *)arg1 = new;
}
return (sysctl_handle_int(oidp, arg1, arg2, req));
return (error);
}
static int
cdg_exp_backoff_scale_handler(SYSCTL_HANDLER_ARGS)
{
int error;
uint32_t new;
if (req->newptr != NULL && CAST_PTR_INT(req->newptr) < 1)
return (EINVAL);
new = *(uint32_t *)arg1;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (new < 1)
error = EINVAL;
else
*(uint32_t *)arg1 = new;
}
return (sysctl_handle_int(oidp, arg1, arg2, req));
return (error);
}
static inline uint32_t

9
sys/netinet/cc/cc_chd.c
View file

@ -78,8 +78,6 @@ __FBSDID("$FreeBSD$");
#include <netinet/khelp/h_ertt.h>
#define CAST_PTR_INT(X) (*((int*)(X)))
/*
* Private signal type for rate based congestion signal.
* See <netinet/cc.h> for appropriate bit-range to use for private signals.
@ -421,7 +419,7 @@ chd_loss_fair_handler(SYSCTL_HANDLER_ARGS)
new = V_chd_loss_fair;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) > 1)
if (new > 1)
error = EINVAL;
else
V_chd_loss_fair = new;
@ -439,8 +437,7 @@ chd_pmax_handler(SYSCTL_HANDLER_ARGS)
new = V_chd_pmax;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) == 0 ||
CAST_PTR_INT(req->newptr) > 100)
if (new == 0 || new > 100)
error = EINVAL;
else
V_chd_pmax = new;
@ -458,7 +455,7 @@ chd_qthresh_handler(SYSCTL_HANDLER_ARGS)
new = V_chd_qthresh;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) <= V_chd_qmin)
if (new <= V_chd_qmin)
error = EINVAL;
else
V_chd_qthresh = new;

8
sys/netinet/cc/cc_dctcp.c
View file

@ -56,8 +56,6 @@ __FBSDID("$FreeBSD$");
#include <netinet/cc/cc.h>
#include <netinet/cc/cc_module.h>
#define CAST_PTR_INT(X) (*((int*)(X)))
#define MAX_ALPHA_VALUE 1024
VNET_DEFINE_STATIC(uint32_t, dctcp_alpha) = 0;
#define V_dctcp_alpha VNET(dctcp_alpha)
@ -400,7 +398,7 @@ dctcp_alpha_handler(SYSCTL_HANDLER_ARGS)
new = V_dctcp_alpha;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) > 1)
if (new > 1)
error = EINVAL;
else {
if (new > MAX_ALPHA_VALUE)
@ -422,7 +420,7 @@ dctcp_shift_g_handler(SYSCTL_HANDLER_ARGS)
new = V_dctcp_shift_g;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) > 1)
if (new > 1)
error = EINVAL;
else
V_dctcp_shift_g = new;
@ -440,7 +438,7 @@ dctcp_slowstart_handler(SYSCTL_HANDLER_ARGS)
new = V_dctcp_slowstart;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) > 1)
if (new > 1)
error = EINVAL;
else
V_dctcp_slowstart = new;

10
sys/netinet/cc/cc_hd.c
View file

@ -79,8 +79,6 @@ __FBSDID("$FreeBSD$");
#include <netinet/khelp/h_ertt.h>
#define CAST_PTR_INT(X) (*((int*)(X)))
/* Largest possible number returned by random(). */
#define RANDOM_MAX INT_MAX
@ -188,8 +186,7 @@ hd_pmax_handler(SYSCTL_HANDLER_ARGS)
new = V_hd_pmax;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) == 0 ||
CAST_PTR_INT(req->newptr) > 100)
if (new == 0 || new > 100)
error = EINVAL;
else
V_hd_pmax = new;
@ -207,7 +204,7 @@ hd_qmin_handler(SYSCTL_HANDLER_ARGS)
new = V_hd_qmin;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) > V_hd_qthresh)
if (new > V_hd_qthresh)
error = EINVAL;
else
V_hd_qmin = new;
@ -225,8 +222,7 @@ hd_qthresh_handler(SYSCTL_HANDLER_ARGS)
new = V_hd_qthresh;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) < 1 ||
CAST_PTR_INT(req->newptr) < V_hd_qmin)
if (new == 0 || new < V_hd_qmin)
error = EINVAL;
else
V_hd_qthresh = new;

18
sys/netinet/cc/cc_newreno.c
View file

@ -79,8 +79,6 @@ __FBSDID("$FreeBSD$");
static MALLOC_DEFINE(M_NEWRENO, "newreno data",
"newreno beta values");
#define CAST_PTR_INT(X) (*((int*)(X)))
static void newreno_cb_destroy(struct cc_var *ccv);
static void newreno_ack_received(struct cc_var *ccv, uint16_t type);
static void newreno_after_idle(struct cc_var *ccv);
@ -364,15 +362,21 @@ newreno_ctl_output(struct cc_var *ccv, struct sockopt *sopt, void *buf)
static int
newreno_beta_handler(SYSCTL_HANDLER_ARGS)
{
int error;
uint32_t new;
if (req->newptr != NULL ) {
new = *(uint32_t *)arg1;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL ) {
if (arg1 == &VNET_NAME(newreno_beta_ecn) && !V_cc_do_abe)
return (EACCES);
if (CAST_PTR_INT(req->newptr) <= 0 || CAST_PTR_INT(req->newptr) > 100)
return (EINVAL);
error = EACCES;
else if (new == 0 || new > 100)
error = EINVAL;
else
*(uint32_t *)arg1 = new;
}
return (sysctl_handle_int(oidp, arg1, arg2, req));
return (error);
}
SYSCTL_DECL(_net_inet_tcp_cc_newreno);

8
sys/netinet/cc/cc_vegas.c
View file

@ -79,8 +79,6 @@ __FBSDID("$FreeBSD$");
#include <netinet/khelp/h_ertt.h>
#define CAST_PTR_INT(X) (*((int*)(X)))
/*
* Private signal type for rate based congestion signal.
* See <netinet/cc.h> for appropriate bit-range to use for private signals.
@ -260,8 +258,7 @@ vegas_alpha_handler(SYSCTL_HANDLER_ARGS)
new = V_vegas_alpha;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) < 1 ||
CAST_PTR_INT(req->newptr) > V_vegas_beta)
if (new == 0 || new > V_vegas_beta)
error = EINVAL;
else
V_vegas_alpha = new;
@ -279,8 +276,7 @@ vegas_beta_handler(SYSCTL_HANDLER_ARGS)
new = V_vegas_beta;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error == 0 && req->newptr != NULL) {
if (CAST_PTR_INT(req->newptr) < 1 ||
CAST_PTR_INT(req->newptr) < V_vegas_alpha)
if (new == 0 || new < V_vegas_alpha)
error = EINVAL;
else
V_vegas_beta = new;

28
sys/netinet/siftr.c
View file

@ -152,8 +152,6 @@ __FBSDID("$FreeBSD$");
#endif
/* useful macros */
#define CAST_PTR_INT(X) (*((int*)(X)))
#define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16)
#define LOWER_SHORT(X) ((X) & 0x0000FFFF)
@ -1442,22 +1440,22 @@ siftr_manage_ops(uint8_t action)
static int
siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
{
if (req->newptr == NULL)
goto skip;
int error;
uint32_t new;
/* If the value passed in isn't 0 or 1, return an error. */
if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1)
return (1);
/* If we are changing state (0 to 1 or 1 to 0). */
if (CAST_PTR_INT(req->newptr) != siftr_enabled )
if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) {
siftr_manage_ops(SIFTR_DISABLE);
return (1);
new = siftr_enabled;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error != 0 && req->newptr != NULL) {
if (new > 1)
return (EINVAL);
else if (new != siftr_enabled) {
error = siftr_manage_ops(new);
if (error != 0)
siftr_manage_ops(SIFTR_DISABLE);
}
}
skip:
return (sysctl_handle_int(oidp, arg1, arg2, req));
return (error);
}