Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull user namespace rlimit handling update from Eric Biederman:
 "This is the work mainly by Alexey Gladkov to limit rlimits to the
  rlimits of the user that created a user namespace, and to allow users
  to have stricter limits on the resources created within a user
  namespace."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  cred: add missing return error code when set_cred_ucounts() failed
  ucounts: Silence warning in dec_rlimit_ucounts
  ucounts: Set ucount_max to the largest positive value the type can hold
  kselftests: Add test to check for rlimit changes in different user namespaces
  Reimplement RLIMIT_MEMLOCK on top of ucounts
  Reimplement RLIMIT_SIGPENDING on top of ucounts
  Reimplement RLIMIT_MSGQUEUE on top of ucounts
  Reimplement RLIMIT_NPROC on top of ucounts
  Use atomic_t for ucounts reference counting
  Add a reference to ucounts for each cred
  Increase size of ucounts to atomic_long_t
This commit is contained in:
Linus Torvalds
2021-06-28 20:39:26 -07:00
29 changed files with 469 additions and 128 deletions

View File

@@ -54,9 +54,15 @@ enum ucount_type {
UCOUNT_FANOTIFY_GROUPS,
UCOUNT_FANOTIFY_MARKS,
#endif
UCOUNT_RLIMIT_NPROC,
UCOUNT_RLIMIT_MSGQUEUE,
UCOUNT_RLIMIT_SIGPENDING,
UCOUNT_RLIMIT_MEMLOCK,
UCOUNT_COUNTS,
};
#define MAX_PER_NAMESPACE_UCOUNTS UCOUNT_RLIMIT_NPROC
struct user_namespace {
struct uid_gid_map uid_map;
struct uid_gid_map gid_map;
@@ -92,23 +98,42 @@ struct user_namespace {
struct ctl_table_header *sysctls;
#endif
struct ucounts *ucounts;
int ucount_max[UCOUNT_COUNTS];
long ucount_max[UCOUNT_COUNTS];
} __randomize_layout;
struct ucounts {
struct hlist_node node;
struct user_namespace *ns;
kuid_t uid;
int count;
atomic_t ucount[UCOUNT_COUNTS];
atomic_t count;
atomic_long_t ucount[UCOUNT_COUNTS];
};
extern struct user_namespace init_user_ns;
extern struct ucounts init_ucounts;
bool setup_userns_sysctls(struct user_namespace *ns);
void retire_userns_sysctls(struct user_namespace *ns);
struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type);
void dec_ucount(struct ucounts *ucounts, enum ucount_type type);
struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid);
struct ucounts * __must_check get_ucounts(struct ucounts *ucounts);
void put_ucounts(struct ucounts *ucounts);
static inline long get_ucounts_value(struct ucounts *ucounts, enum ucount_type type)
{
return atomic_long_read(&ucounts->ucount[type]);
}
long inc_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
bool dec_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v);
bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsigned long max);
static inline void set_rlimit_ucount_max(struct user_namespace *ns,
enum ucount_type type, unsigned long max)
{
ns->ucount_max[type] = max <= LONG_MAX ? max : LONG_MAX;
}
#ifdef CONFIG_USER_NS