diff options
Diffstat (limited to 'security/commoncap.c')
| -rw-r--r-- | security/commoncap.c | 44 |
1 files changed, 27 insertions, 17 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index 01ab478..5aba826 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -25,20 +25,6 @@ #include <linux/mount.h> #include <linux/sched.h> -#ifdef CONFIG_SECURITY_FILE_CAPABILITIES -/* - * Because of the reduced scope of CAP_SETPCAP when filesystem - * capabilities are in effect, it is safe to allow this capability to - * be available in the default configuration. - */ -# define CAP_INIT_BSET CAP_FULL_SET -#else /* ie. ndef CONFIG_SECURITY_FILE_CAPABILITIES */ -# define CAP_INIT_BSET CAP_INIT_EFF_SET -#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ - -kernel_cap_t cap_bset = CAP_INIT_BSET; /* systemwide capability bound */ -EXPORT_SYMBOL(cap_bset); - /* Global security state */ unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */ @@ -140,6 +126,12 @@ int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, /* incapable of using this inheritable set */ return -EPERM; } + if (!cap_issubset(*inheritable, + cap_combine(target->cap_inheritable, + current->cap_bset))) { + /* no new pI capabilities outside bounding set */ + return -EPERM; + } /* verify restrictions on target's new Permitted set */ if (!cap_issubset (*permitted, @@ -337,10 +329,11 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) /* Derived from fs/exec.c:compute_creds. */ kernel_cap_t new_permitted, working; - new_permitted = cap_intersect (bprm->cap_permitted, cap_bset); - working = cap_intersect (bprm->cap_inheritable, + new_permitted = cap_intersect(bprm->cap_permitted, + current->cap_bset); + working = cap_intersect(bprm->cap_inheritable, current->cap_inheritable); - new_permitted = cap_combine (new_permitted, working); + new_permitted = cap_combine(new_permitted, working); if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || !cap_issubset (new_permitted, current->cap_permitted)) { @@ -581,6 +574,23 @@ int cap_task_kill(struct task_struct *p, struct siginfo *info, return -EPERM; } + +/* + * called from kernel/sys.c for prctl(PR_CABSET_DROP) + * done without task_capability_lock() because it introduces + * no new races - i.e. only another task doing capget() on + * this task could get inconsistent info. There can be no + * racing writer bc a task can only change its own caps. + */ +long cap_prctl_drop(unsigned long cap) +{ + if (!capable(CAP_SETPCAP)) + return -EPERM; + if (!cap_valid(cap)) + return -EINVAL; + cap_lower(current->cap_bset, cap); + return 0; +} #else int cap_task_setscheduler (struct task_struct *p, int policy, struct sched_param *lp) |
