diff options
Diffstat (limited to 'ipc/mq_sysctl.c')
| -rw-r--r-- | ipc/mq_sysctl.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c index ebb5ed81c151..0dd12e1c9f53 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; @@ -19,7 +20,7 @@ static int msg_max_limit_max = HARD_MSGMAX; static int msg_maxsize_limit_min = MIN_MSGSIZEMAX; static int msg_maxsize_limit_max = HARD_MSGSIZEMAX; -static struct ctl_table mq_sysctls[] = { +static const struct ctl_table mq_sysctls[] = { { .procname = "queues_max", .data = &init_ipc_ns.mq_queues_max, @@ -63,7 +64,6 @@ static struct ctl_table mq_sysctls[] = { .extra1 = &msg_maxsize_limit_min, .extra2 = &msg_maxsize_limit_max, }, - {} }; static struct ctl_table_set *set_lookup(struct ctl_table_root *root) @@ -76,8 +76,42 @@ static int set_is_seen(struct ctl_table_set *set) return ¤t->nsproxy->ipc_ns->mq_set == set; } +static void mq_set_ownership(struct ctl_table_header *head, + 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, const struct ctl_table *table) +{ + int mode = table->mode; + kuid_t ns_root_uid; + kgid_t ns_root_gid; + + mq_set_ownership(head, &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) @@ -124,7 +158,7 @@ bool setup_mq_sysctls(struct ipc_namespace *ns) void retire_mq_sysctls(struct ipc_namespace *ns) { - struct ctl_table *tbl; + const struct ctl_table *tbl; tbl = ns->mq_sysctls->ctl_table_arg; unregister_sysctl_table(ns->mq_sysctls); |