execute: try to suppress PR_SET_SECUREBITS if unnecessary

This commit is contained in:
Lennart Poettering 2010-03-31 16:25:33 +02:00
parent 5021be21bf
commit 693ced4872
1 changed files with 16 additions and 7 deletions

View File

@ -461,9 +461,13 @@ static int enforce_user(const ExecContext *context, uid_t uid) {
/* First step: If we need to keep capabilities but
* drop privileges we need to make sure we keep our
* caps, whiel we drop priviliges. */
if (uid != 0)
if (prctl(PR_SET_SECUREBITS, context->secure_bits|SECURE_KEEP_CAPS) < 0)
return -errno;
if (uid != 0) {
int sb = context->secure_bits|SECURE_KEEP_CAPS;
if (prctl(PR_GET_SECUREBITS) != sb)
if (prctl(PR_SET_SECUREBITS, sb) < 0)
return -errno;
}
/* Second step: set the capabilites. This will reduce
* the capabilities to the minimum we need. */
@ -671,10 +675,15 @@ int exec_spawn(const ExecCommand *command,
goto fail;
}
if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
r = EXIT_SECUREBITS;
goto fail;
}
/* PR_GET_SECUREBITS is not priviliged, while
* PR_SET_SECUREBITS is. So to suppress
* potential EPERMs we'll try not to call
* PR_SET_SECUREBITS unless necessary. */
if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
r = EXIT_SECUREBITS;
goto fail;
}
if (context->capabilities)
if (cap_set_proc(context->capabilities) < 0) {