X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Fcapability.c;h=915ceb9d9b1a4749206bebb638a971f7dcac156c;hb=ac6e2f0dfc2e800f01c79ecea2b811914110a7b9;hp=3f2f27e23fe4234c2660da30e5d99f76549aff14;hpb=7d328b544621d4b1bec936dec612947ad8bfb65a;p=elogind.git

diff --git a/src/shared/capability.c b/src/shared/capability.c
index 3f2f27e23..915ceb9d9 100644
--- a/src/shared/capability.c
+++ b/src/shared/capability.c
@@ -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) {