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| author | Eric Paris <eparis@redhat.com> | 2013-05-24 09:18:04 -0400 |
|---|---|---|
| committer | Eric Paris <eparis@redhat.com> | 2013-11-05 11:08:13 -0500 |
| commit | d040e5af380554c23ffe0a034ae5f3e53da93a1d (patch) | |
| tree | 637a2e206c56b1cd2be32f8ef92bea19e25a3e9c | |
| parent | 81407c84ace88368ff23abb81caaeacf050c8450 (diff) | |
| download | op-kernel-dev-d040e5af380554c23ffe0a034ae5f3e53da93a1d.zip op-kernel-dev-d040e5af380554c23ffe0a034ae5f3e53da93a1d.tar.gz | |
audit: audit feature to only allow unsetting the loginuid
This is a new audit feature which only grants processes with
CAP_AUDIT_CONTROL the ability to unset their loginuid. They cannot
directly set it from a valid uid to another valid uid. The ability to
unset the loginuid is nice because a priviledged task, like that of
container creation, can unset the loginuid and then priv is not needed
inside the container when a login daemon needs to set the loginuid.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
| -rw-r--r-- | include/uapi/linux/audit.h | 3 | ||||
| -rw-r--r-- | kernel/audit.c | 3 | ||||
| -rw-r--r-- | kernel/auditsc.c | 3 |
3 files changed, 7 insertions, 2 deletions
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index 9eddf2c..05e5e8f 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -386,7 +386,8 @@ struct audit_features { __u32 lock; /* which features to lock */ }; -#define AUDIT_LAST_FEATURE -1 +#define AUDIT_FEATURE_ONLY_UNSET_LOGINUID 0 +#define AUDIT_LAST_FEATURE AUDIT_FEATURE_ONLY_UNSET_LOGINUID #define audit_feature_valid(x) ((x) >= 0 && (x) <= AUDIT_LAST_FEATURE) #define AUDIT_FEATURE_TO_MASK(x) (1 << ((x) & 31)) /* mask for __u32 */ diff --git a/kernel/audit.c b/kernel/audit.c index 29ee6a4..fbfa3a7 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -144,7 +144,8 @@ static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, .features = 0, .lock = 0,}; -static char *audit_feature_names[0] = { +static char *audit_feature_names[1] = { + "only_unset_loginuid", }; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index c75d781..924c0bf 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1974,6 +1974,9 @@ static int audit_set_loginuid_perm(kuid_t loginuid) /* it is set, you need permission */ if (!capable(CAP_AUDIT_CONTROL)) return -EPERM; + /* reject if this is not an unset and we don't allow that */ + if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid)) + return -EPERM; return 0; } |
