diff options
Diffstat (limited to 'security/commoncap.c')
| -rw-r--r-- | security/commoncap.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index 79713545cd63..7f0b2a68717d 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -43,28 +43,44 @@ int cap_netlink_recv(struct sk_buff *skb, int cap) EXPORT_SYMBOL(cap_netlink_recv); /** - * cap_capable - Determine whether a task has a particular effective capability - * @tsk: The task to query + * cap_capable - Determine whether current has a particular effective capability * @cap: The capability to check for * @audit: Whether to write an audit message or not * * Determine whether the nominated task has the specified capability amongst - * its effective set, returning 0 if it does, -ve if it does not. + * its effective set, returning 0 if it does, -ve if it does not. Note that + * this uses current's subjective/effective credentials. * * NOTE WELL: cap_capable() cannot be used like the kernel's capable() * function. That is, it has the reverse semantics: cap_capable() returns 0 * when a task has a capability, but the kernel's capable() returns 1 for this * case. */ -int cap_capable(struct task_struct *tsk, int cap, int audit) +int cap_capable(int cap, int audit) { - __u32 cap_raised; + return cap_raised(current_cap(), cap) ? 0 : -EPERM; +} - /* Derived from include/linux/sched.h:capable. */ - rcu_read_lock(); - cap_raised = cap_raised(__task_cred(tsk)->cap_effective, cap); - rcu_read_unlock(); - return cap_raised ? 0 : -EPERM; +/** + * cap_has_capability - Determine whether a task has a particular effective capability + * @tsk: The task to query + * @cred: The credentials to use + * @cap: The capability to check for + * @audit: Whether to write an audit message or not + * + * Determine whether the nominated task has the specified capability amongst + * its effective set, returning 0 if it does, -ve if it does not. Note that + * this uses the task's objective/real credentials. + * + * NOTE WELL: cap_has_capability() cannot be used like the kernel's + * has_capability() function. That is, it has the reverse semantics: + * cap_has_capability() returns 0 when a task has a capability, but the + * kernel's has_capability() returns 1 for this case. + */ +int cap_task_capable(struct task_struct *tsk, const struct cred *cred, int cap, + int audit) +{ + return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM; } /** @@ -160,7 +176,7 @@ 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, CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0) + if (cap_capable(CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0) return 0; #endif return 1; @@ -869,7 +885,7 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, & (new->securebits ^ arg2)) /*[1]*/ || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ - || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/ + || (cap_capable(CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/ /* * [1] no changing of bits that are locked * [2] no unlocking of locks @@ -950,7 +966,7 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages) { int cap_sys_admin = 0; - if (cap_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0) + if (cap_capable(CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0) cap_sys_admin = 1; return __vm_enough_memory(mm, pages, cap_sys_admin); } |