Pull security docs update from James Morris. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: security: Minor improvements to no_new_privs documentation
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| @@ -25,6 +25,13 @@ bits will no longer change the uid or gid; file capabilities will not · 24 unmodified lines | |||
| 25 | add to the permitted set, and LSMs will not relax constraints after | 25 | add to the permitted set, and LSMs will not relax constraints after |
| 26 | execve. | 26 | execve. |
| 27 | 27 | ||
| 28 | To set no_new_privs, use prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0). | ||
| 29 | |||
| 30 | Be careful, though: LSMs might also not tighten constraints on exec | ||
| 31 | in no_new_privs mode. (This means that setting up a general-purpose | ||
| 32 | service launcher to set no_new_privs before execing daemons may | ||
| 33 | interfere with LSM-based sandboxing.) | ||
| 34 | |||
| 28 | Note that no_new_privs does not prevent privilege changes that do not | 35 | Note that no_new_privs does not prevent privilege changes that do not |
| 29 | involve execve. An appropriately privileged task can still call | 36 | involve execve. An appropriately privileged task can still call |
| 30 | setuid(2) and receive SCM_RIGHTS datagrams. | 37 | setuid(2) and receive SCM_RIGHTS datagrams. |
| @@ -141,6 +141,8 @@ · 140 unmodified lines | |||
| 141 | * Changing LSM security domain is considered a new privilege. So, for example, | 141 | * Changing LSM security domain is considered a new privilege. So, for example, |
| 142 | * asking selinux for a specific new context (e.g. with runcon) will result | 142 | * asking selinux for a specific new context (e.g. with runcon) will result |
| 143 | * in execve returning -EPERM. | 143 | * in execve returning -EPERM. |
| 144 | * | ||
| 145 | * See Documentation/prctl/no_new_privs.txt for more details. | ||
| 144 | */ | 146 | */ |
| 145 | #define PR_SET_NO_NEW_PRIVS 38 | 147 | #define PR_SET_NO_NEW_PRIVS 38 |
| 146 | #define PR_GET_NO_NEW_PRIVS 39 | 148 | #define PR_GET_NO_NEW_PRIVS 39 |