chiark / gitweb /
fsckd daemon for inter-fsckd communication
[elogind.git] / src / shared / capability.c
index 3f2f27e23fe4234c2660da30e5d99f76549aff14..915ceb9d9b1a4749206bebb638a971f7dcac156c 100644 (file)
@@ -269,12 +269,16 @@ int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities) {
                 return log_oom();
 
         if (keep_capabilities) {
-                cap_value_t bits[log2u64(keep_capabilities)];
+                cap_value_t bits[u64log2(keep_capabilities) + 1];
 
                 for (i = 0; i < ELEMENTSOF(bits); i++)
                         if (keep_capabilities & (1ULL << i))
                                 bits[j++] = i;
-                assert((keep_capabilities & (~1ULL << i)) == 0);
+
+                /* use enough bits */
+                assert(i == 64 || (keep_capabilities >> i) == 0);
+                /* don't use too many bits */
+                assert(keep_capabilities & (1ULL << (i - 1)));
 
                 if (cap_set_flag(d, CAP_EFFECTIVE, j, bits, CAP_SET) < 0 ||
                     cap_set_flag(d, CAP_PERMITTED, j, bits, CAP_SET) < 0) {