nspawn: Allow Capability= to overrule private network setting

The commit:

a3fc6b55ac nspawn: mask out CAP_NET_ADMIN again if settings file turns off private networking

turned off the CAP_NET_ADMIN capability whenever no private networking
feature was enabled. This broke configurations where the CAP_NET_ADMIN
capability was explicitly requested in the configuration.

Changing the order of evalution here to allow the Capability= setting
to overrule this implicit setting:

Order of evaluation:

1. if no private network setting is enabled, CAP_NET_ADMIN is removed
2. if a private network setting is enabled, CAP_NET_ADMIN is added
3. the settings of Capability= are added
4. the settings of DropCapability= are removed

This allows the fix for #11755 to be retained and to still allow the
admin to specify CAP_NET_ADMIN as additional capability.

Fixes: a3fc6b55ac
Fixes: #13995
This commit is contained in:
Torsten Hilbrich 2019-11-12 08:36:06 +01:00 committed by Lennart Poettering
parent 7edd8fb198
commit 7be830c6e8
1 changed files with 5 additions and 2 deletions

View File

@ -3770,6 +3770,7 @@ static int merge_settings(Settings *settings, const char *path) {
if ((arg_settings_mask & SETTING_CAPABILITY) == 0) {
uint64_t plus, minus;
uint64_t network_minus = 0;
/* Note that we copy both the simple plus/minus caps here, and the full quintet from the
* Settings structure */
@ -3781,14 +3782,16 @@ static int merge_settings(Settings *settings, const char *path) {
if (settings_private_network(settings))
plus |= UINT64_C(1) << CAP_NET_ADMIN;
else
minus |= UINT64_C(1) << CAP_NET_ADMIN;
network_minus |= UINT64_C(1) << CAP_NET_ADMIN;
}
if (!arg_settings_trusted && plus != 0) {
if (settings->capability != 0)
log_warning("Ignoring Capability= setting, file %s is not trusted.", path);
} else
} else {
arg_caps_retain &= ~network_minus;
arg_caps_retain |= plus;
}
arg_caps_retain &= ~minus;