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-rw-r--r--ipc/mq_sysctl.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
index ebb5ed81c151..21fba3a6edaf 100644
--- a/ipc/mq_sysctl.c
+++ b/ipc/mq_sysctl.c
@@ -12,6 +12,7 @@
#include <linux/stat.h>
#include <linux/capability.h>
#include <linux/slab.h>
+#include <linux/cred.h>
static int msg_max_limit_min = MIN_MSGMAX;
static int msg_max_limit_max = HARD_MSGMAX;
@@ -76,8 +77,43 @@ static int set_is_seen(struct ctl_table_set *set)
return &current->nsproxy->ipc_ns->mq_set == set;
}
+static void mq_set_ownership(struct ctl_table_header *head,
+ struct ctl_table *table,
+ kuid_t *uid, kgid_t *gid)
+{
+ struct ipc_namespace *ns =
+ container_of(head->set, struct ipc_namespace, mq_set);
+
+ kuid_t ns_root_uid = make_kuid(ns->user_ns, 0);
+ kgid_t ns_root_gid = make_kgid(ns->user_ns, 0);
+
+ *uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID;
+ *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID;
+}
+
+static int mq_permissions(struct ctl_table_header *head, struct ctl_table *table)
+{
+ int mode = table->mode;
+ kuid_t ns_root_uid;
+ kgid_t ns_root_gid;
+
+ mq_set_ownership(head, table, &ns_root_uid, &ns_root_gid);
+
+ if (uid_eq(current_euid(), ns_root_uid))
+ mode >>= 6;
+
+ else if (in_egroup_p(ns_root_gid))
+ mode >>= 3;
+
+ mode &= 7;
+
+ return (mode << 6) | (mode << 3) | mode;
+}
+
static struct ctl_table_root set_root = {
.lookup = set_lookup,
+ .permissions = mq_permissions,
+ .set_ownership = mq_set_ownership,
};
bool setup_mq_sysctls(struct ipc_namespace *ns)