X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Fcapability.c;h=8dbe4da5bbbe1280518e81bca9af166549f06bf1;hb=b733fbe7a0214eb43e402db7179697bf9c0975c1;hp=dcf7ce1a69ec58b252c4dcf1bc06ace259b5c48e;hpb=51ddf61540976fc7b09ce5ace707b27f3acc3871;p=elogind.git

diff --git a/src/shared/capability.c b/src/shared/capability.c
index dcf7ce1a6..8dbe4da5b 100644
--- a/src/shared/capability.c
+++ b/src/shared/capability.c
@@ -19,14 +19,9 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <assert.h>
-#include <string.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
-#include <sys/types.h>
-#include <stdarg.h>
-#include <ctype.h>
 #include <sys/capability.h>
 #include <sys/prctl.h>
 #include "grp.h"
@@ -55,7 +50,7 @@ unsigned long cap_last_cap(void) {
         static thread_local unsigned long saved;
         static thread_local bool valid = false;
         _cleanup_free_ char *content = NULL;
-        unsigned long p;
+        unsigned long p = 0;
         int r;
 
         if (valid)
@@ -209,7 +204,7 @@ static int drop_from_file(const char *fn, uint64_t drop) {
         if (asprintf(&p, "%u %u", lo, hi) < 0)
                 return -ENOMEM;
 
-        r = write_string_file(fn, p);
+        r = write_string_file(fn, p, WRITE_STRING_FILE_CREATE);
         free(p);
 
         return r;
@@ -269,12 +264,17 @@ int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities) {
                 return log_oom();
 
         if (keep_capabilities) {
-                cap_value_t bits[sizeof(keep_capabilities)*8];
+                cap_value_t bits[u64log2(keep_capabilities) + 1];
 
-                for (i = 0; i < sizeof(keep_capabilities)*8; i++)
+                for (i = 0; i < ELEMENTSOF(bits); i++)
                         if (keep_capabilities & (1ULL << i))
                                 bits[j++] = i;
 
+                /* 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) {
                         log_error_errno(errno, "Failed to enable capabilities bits: %m");