4 files changed, 25 insertions, 13 deletions

diff --git a/src/libsystemd/sd-bus/bus-control.c b/src/libsystemd/sd-bus/bus-control.c
index e86546c343..b2394db3eb 100644
--- a/src/libsystemd/sd-bus/bus-control.c
+++ b/src/libsystemd/sd-bus/bus-control.c
@@ -33,6 +33,7 @@
 #include "bus-control.h"
 #include "bus-bloom.h"
 #include "bus-util.h"
+#include "capability.h"
 #include "cgroup-util.h"
 
 _public_ int sd_bus_get_unique_name(sd_bus *bus, const char **unique) {
@@ -520,8 +521,11 @@ static int bus_populate_creds_from_items(
                              SD_BUS_CREDS_INHERITABLE_CAPS | SD_BUS_CREDS_BOUNDING_CAPS) & mask;
 
                         if (m) {
-                                c->capability_size = item->size - offsetof(struct kdbus_item, caps.caps);
-                                c->capability = memdup(item->caps.caps, c->capability_size);
+                                if (item->caps.last_cap != cap_last_cap() ||
+                                    item->size - offsetof(struct kdbus_item, caps.caps) < DIV_ROUND_UP(item->caps.last_cap, 32U) * 4 * 4)
+                                        return -EBADMSG;
+
+                                c->capability = memdup(item->caps.caps, item->size - offsetof(struct kdbus_item, caps.caps));
                                 if (!c->capability)
                                         return -ENOMEM;
 
diff --git a/src/libsystemd/sd-bus/bus-creds.c b/src/libsystemd/sd-bus/bus-creds.c
index 9978ddfa38..55d6fb6b43 100644
--- a/src/libsystemd/sd-bus/bus-creds.c
+++ b/src/libsystemd/sd-bus/bus-creds.c
@@ -22,6 +22,7 @@
 #include <stdlib.h>
 
 #include "util.h"
+#include "capability.h"
 #include "cgroup-util.h"
 #include "fileio.h"
 #include "audit.h"
@@ -588,10 +589,11 @@ static int has_cap(sd_bus_creds *c, unsigned offset, int capability) {
         size_t sz;
 
         assert(c);
+        assert(capability >= 0);
         assert(c->capability);
 
-        sz = c->capability_size / 4;
-        if ((size_t) capability >= sz*8)
+        sz = DIV_ROUND_UP(cap_last_cap(), 32U) * 4;
+        if ((unsigned)capability > cap_last_cap())
                 return 0;
 
         return !!(c->capability[offset * sz + (capability / 8)] & (1 << (capability % 8)));
@@ -638,12 +640,13 @@ _public_ int sd_bus_creds_has_bounding_cap(sd_bus_creds *c, int capability) {
 }
 
 static int parse_caps(sd_bus_creds *c, unsigned offset, const char *p) {
-        size_t sz;
+        size_t sz, max;
         unsigned i;
 
         assert(c);
         assert(p);
 
+        max = DIV_ROUND_UP(cap_last_cap(), 32U) * 4;
         p += strspn(p, WHITESPACE);
 
         sz = strlen(p);
@@ -651,12 +654,13 @@ static int parse_caps(sd_bus_creds *c, unsigned offset, const char *p) {
                 return -EINVAL;
 
         sz /= 2;
+        if (sz > max)
+                return -EINVAL;
+
         if (!c->capability) {
-                c->capability = new0(uint8_t, sz * 4);
+                c->capability = new0(uint8_t, max * 4);
                 if (!c->capability)
                         return -ENOMEM;
-
-                c->capability_size = sz * 4;
         }
 
         for (i = 0; i < sz; i ++) {
@@ -668,7 +672,7 @@ static int parse_caps(sd_bus_creds *c, unsigned offset, const char *p) {
                 if (x < 0 || y < 0)
                         return -EINVAL;
 
-                c->capability[offset * sz + (sz - i - 1)] = (uint8_t) x << 4 | (uint8_t) y;
+                c->capability[offset * max + (sz - i - 1)] = (uint8_t) x << 4 | (uint8_t) y;
         }
 
         return 0;
@@ -1073,11 +1077,10 @@ int bus_creds_extend_by_pid(sd_bus_creds *c, uint64_t mask, sd_bus_creds **ret)
         }
 
         if (c->mask & mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS)) {
-                n->capability = memdup(c->capability, c->capability_size);
+                n->capability = memdup(c->capability, DIV_ROUND_UP(cap_last_cap(), 32U) * 4 * 4);
                 if (!n->capability)
                         return -ENOMEM;
 
-                n->capability_size = c->capability_size;
                 n->mask |= c->mask & mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS);
         }
 
diff --git a/src/libsystemd/sd-bus/bus-creds.h b/src/libsystemd/sd-bus/bus-creds.h
index 48453e2afd..2480a4a0b1 100644
--- a/src/libsystemd/sd-bus/bus-creds.h
+++ b/src/libsystemd/sd-bus/bus-creds.h
@@ -61,7 +61,6 @@ struct sd_bus_creds {
         char *slice;
 
         uint8_t *capability;
-        size_t capability_size;
 
         uint32_t audit_session_id;
         uid_t audit_login_uid;
diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index d9252b2560..eeb4a518d1 100644
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -32,6 +32,7 @@
 #include "util.h"
 #include "strv.h"
 #include "memfd-util.h"
+#include "capability.h"
 #include "cgroup-util.h"
 #include "fileio.h"
 
@@ -673,8 +674,13 @@ static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
                         break;
 
                 case KDBUS_ITEM_CAPS:
+                        if (d->caps.last_cap != cap_last_cap() ||
+                            d->size - offsetof(struct kdbus_item, caps.caps) < DIV_ROUND_UP(d->caps.last_cap, 32U) * 4 * 4) {
+                                r = -EBADMSG;
+                                goto fail;
+                        }
+
                         m->creds.capability = (uint8_t *) d->caps.caps;
-                        m->creds.capability_size = d->size - offsetof(struct kdbus_item, caps.caps);
                         m->creds.mask |= (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS) & bus->creds_mask;
                         break;