diff options
Diffstat (limited to 'security/commoncap.c')
| -rw-r--r-- | security/commoncap.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index 6dbae4650ab..b9d613e0ef1 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -76,24 +76,33 @@ int cap_netlink_send(struct sock *sk, struct sk_buff *skb) int cap_capable(const struct cred *cred, struct user_namespace *targ_ns, int cap, int audit) { - for (;;) { - /* The owner of the user namespace has all caps. */ - if (targ_ns != &init_user_ns && uid_eq(targ_ns->owner, cred->euid)) - return 0; + struct user_namespace *ns = targ_ns; + /* See if cred has the capability in the target user namespace + * by examining the target user namespace and all of the target + * user namespace's parents. + */ + for (;;) { /* Do we have the necessary capabilities? */ - if (targ_ns == cred->user_ns) + if (ns == cred->user_ns) return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM; /* Have we tried all of the parent namespaces? */ - if (targ_ns == &init_user_ns) + if (ns == &init_user_ns) return -EPERM; + /* + * The owner of the user namespace in the parent of the + * user namespace has all caps. + */ + if ((ns->parent == cred->user_ns) && uid_eq(ns->owner, cred->euid)) + return 0; + /* - *If you have a capability in a parent user ns, then you have + * If you have a capability in a parent user ns, then you have * it over all children user namespaces as well. */ - targ_ns = targ_ns->parent; + ns = ns->parent; } /* We never get here */ @@ -431,7 +440,7 @@ static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_c if (!file_caps_enabled) return 0; - if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) + if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) return 0; dentry = dget(bprm->file->f_dentry); @@ -759,16 +768,16 @@ int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) */ static int cap_safe_nice(struct task_struct *p) { - int is_subset; + int is_subset, ret = 0; rcu_read_lock(); is_subset = cap_issubset(__task_cred(p)->cap_permitted, current_cred()->cap_permitted); + if (!is_subset && !ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) + ret = -EPERM; rcu_read_unlock(); - if (!is_subset && !capable(CAP_SYS_NICE)) - return -EPERM; - return 0; + return ret; } /** @@ -815,7 +824,7 @@ int cap_task_setnice(struct task_struct *p, int nice) */ static long cap_prctl_drop(struct cred *new, unsigned long cap) { - if (!capable(CAP_SETPCAP)) + if (!ns_capable(current_user_ns(), CAP_SETPCAP)) return -EPERM; if (!cap_valid(cap)) return -EINVAL; |