diff options
Diffstat (limited to 'security/commoncap.c')
-rw-r--r-- | security/commoncap.c | 61 |
1 files changed, 36 insertions, 25 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index f80d1160939..e771cb1b2d7 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -77,12 +77,12 @@ int cap_capable(const struct cred *cred, struct user_namespace *targ_ns, int cap, int audit) { for (;;) { - /* The creator of the user namespace has all caps. */ - if (targ_ns != &init_user_ns && targ_ns->creator == cred->user) + /* The owner of the user namespace has all caps. */ + if (targ_ns != &init_user_ns && uid_eq(targ_ns->owner, cred->euid)) return 0; /* Do we have the necessary capabilities? */ - if (targ_ns == cred->user->user_ns) + if (targ_ns == cred->user_ns) return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM; /* Have we tried all of the parent namespaces? */ @@ -93,7 +93,7 @@ int cap_capable(const struct cred *cred, struct user_namespace *targ_ns, *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->creator->user_ns; + targ_ns = targ_ns->parent; } /* We never get here */ @@ -137,10 +137,10 @@ int cap_ptrace_access_check(struct task_struct *child, unsigned int mode) rcu_read_lock(); cred = current_cred(); child_cred = __task_cred(child); - if (cred->user->user_ns == child_cred->user->user_ns && + if (cred->user_ns == child_cred->user_ns && cap_issubset(child_cred->cap_permitted, cred->cap_permitted)) goto out; - if (ns_capable(child_cred->user->user_ns, CAP_SYS_PTRACE)) + if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) goto out; ret = -EPERM; out: @@ -169,10 +169,10 @@ int cap_ptrace_traceme(struct task_struct *parent) rcu_read_lock(); cred = __task_cred(parent); child_cred = current_cred(); - if (cred->user->user_ns == child_cred->user->user_ns && + if (cred->user_ns == child_cred->user_ns && cap_issubset(child_cred->cap_permitted, cred->cap_permitted)) goto out; - if (has_ns_capability(parent, child_cred->user->user_ns, CAP_SYS_PTRACE)) + if (has_ns_capability(parent, child_cred->user_ns, CAP_SYS_PTRACE)) goto out; ret = -EPERM; out: @@ -215,7 +215,7 @@ static inline int cap_inh_is_capped(void) /* they are so limited unless the current task has the CAP_SETPCAP * capability */ - if (cap_capable(current_cred(), current_cred()->user->user_ns, + if (cap_capable(current_cred(), current_cred()->user_ns, CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0) return 0; return 1; @@ -473,19 +473,22 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) struct cred *new = bprm->cred; bool effective, has_cap = false; int ret; + kuid_t root_uid; effective = false; ret = get_file_caps(bprm, &effective, &has_cap); if (ret < 0) return ret; + root_uid = make_kuid(new->user_ns, 0); + if (!issecure(SECURE_NOROOT)) { /* * If the legacy file capability is set, then don't set privs * for a setuid root binary run by a non-root user. Do set it * for a root user just to cause least surprise to an admin. */ - if (has_cap && new->uid != 0 && new->euid == 0) { + if (has_cap && !uid_eq(new->uid, root_uid) && uid_eq(new->euid, root_uid)) { warn_setuid_and_fcaps_mixed(bprm->filename); goto skip; } @@ -496,12 +499,12 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) * * If only the real uid is 0, we do not set the effective bit. */ - if (new->euid == 0 || new->uid == 0) { + if (uid_eq(new->euid, root_uid) || uid_eq(new->uid, root_uid)) { /* pP' = (cap_bset & ~0) | (pI & ~0) */ new->cap_permitted = cap_combine(old->cap_bset, old->cap_inheritable); } - if (new->euid == 0) + if (uid_eq(new->euid, root_uid)) effective = true; } skip: @@ -516,8 +519,8 @@ skip: * * In addition, if NO_NEW_PRIVS, then ensure we get no new privs. */ - if ((new->euid != old->uid || - new->egid != old->gid || + if ((!uid_eq(new->euid, old->uid) || + !gid_eq(new->egid, old->gid) || !cap_issubset(new->cap_permitted, old->cap_permitted)) && bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) { /* downgrade; they get no more than they had, and maybe less */ @@ -553,7 +556,7 @@ skip: */ if (!cap_isclear(new->cap_effective)) { if (!cap_issubset(CAP_FULL_SET, new->cap_effective) || - new->euid != 0 || new->uid != 0 || + !uid_eq(new->euid, root_uid) || !uid_eq(new->uid, root_uid) || issecure(SECURE_NOROOT)) { ret = audit_log_bprm_fcaps(bprm, new, old); if (ret < 0) @@ -578,16 +581,17 @@ skip: int cap_bprm_secureexec(struct linux_binprm *bprm) { const struct cred *cred = current_cred(); + kuid_t root_uid = make_kuid(cred->user_ns, 0); - if (cred->uid != 0) { + if (!uid_eq(cred->uid, root_uid)) { if (bprm->cap_effective) return 1; if (!cap_isclear(cred->cap_permitted)) return 1; } - return (cred->euid != cred->uid || - cred->egid != cred->gid); + return (!uid_eq(cred->euid, cred->uid) || + !gid_eq(cred->egid, cred->gid)); } /** @@ -677,15 +681,21 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) */ static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) { - if ((old->uid == 0 || old->euid == 0 || old->suid == 0) && - (new->uid != 0 && new->euid != 0 && new->suid != 0) && + kuid_t root_uid = make_kuid(old->user_ns, 0); + + if ((uid_eq(old->uid, root_uid) || + uid_eq(old->euid, root_uid) || + uid_eq(old->suid, root_uid)) && + (!uid_eq(new->uid, root_uid) && + !uid_eq(new->euid, root_uid) && + !uid_eq(new->suid, root_uid)) && !issecure(SECURE_KEEP_CAPS)) { cap_clear(new->cap_permitted); cap_clear(new->cap_effective); } - if (old->euid == 0 && new->euid != 0) + if (uid_eq(old->euid, root_uid) && !uid_eq(new->euid, root_uid)) cap_clear(new->cap_effective); - if (old->euid != 0 && new->euid == 0) + if (!uid_eq(old->euid, root_uid) && uid_eq(new->euid, root_uid)) new->cap_effective = new->cap_permitted; } @@ -718,11 +728,12 @@ int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) * if not, we might be a bit too harsh here. */ if (!issecure(SECURE_NO_SETUID_FIXUP)) { - if (old->fsuid == 0 && new->fsuid != 0) + kuid_t root_uid = make_kuid(old->user_ns, 0); + if (uid_eq(old->fsuid, root_uid) && !uid_eq(new->fsuid, root_uid)) new->cap_effective = cap_drop_fs_set(new->cap_effective); - if (old->fsuid != 0 && new->fsuid == 0) + if (!uid_eq(old->fsuid, root_uid) && uid_eq(new->fsuid, root_uid)) new->cap_effective = cap_raise_fs_set(new->cap_effective, new->cap_permitted); @@ -875,7 +886,7 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ || (cap_capable(current_cred(), - current_cred()->user->user_ns, CAP_SETPCAP, + current_cred()->user_ns, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/ /* * [1] no changing of bits that are locked |