diff options
| -rw-r--r-- | include/linux/capability.h | 17 | ||||
| -rw-r--r-- | include/linux/security.h | 41 | ||||
| -rw-r--r-- | kernel/capability.c | 2 | ||||
| -rw-r--r-- | security/commoncap.c | 29 | ||||
| -rw-r--r-- | security/security.c | 26 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 16 |
6 files changed, 94 insertions, 37 deletions
diff --git a/include/linux/capability.h b/include/linux/capability.h index e22f48c..02bdb76 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -529,8 +529,21 @@ extern const kernel_cap_t __cap_init_eff_set; * * Note that this does not set PF_SUPERPRIV on the task. */ -#define has_capability(t, cap) (security_capable((t), (cap)) == 0) -#define has_capability_noaudit(t, cap) (security_capable_noaudit((t), (cap)) == 0) +#define has_capability(t, cap) (security_real_capable((t), (cap)) == 0) + +/** + * has_capability_noaudit - Determine if a task has a superior capability available (unaudited) + * @t: The task in question + * @cap: The capability to be tested for + * + * Return true if the specified task has the given superior capability + * currently in effect, false if not, but don't write an audit message for the + * check. + * + * Note that this does not set PF_SUPERPRIV on the task. + */ +#define has_capability_noaudit(t, cap) \ + (security_real_capable_noaudit((t), (cap)) == 0) extern int capable(int cap); diff --git a/include/linux/security.h b/include/linux/security.h index 3416cb8..f9c3904 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -48,7 +48,8 @@ struct audit_krule; * These functions are in security/capability.c and are used * as the default capabilities functions */ -extern int cap_capable(struct task_struct *tsk, int cap, int audit); +extern int cap_capable(struct task_struct *tsk, const struct cred *cred, + int cap, int audit); extern int cap_settime(struct timespec *ts, struct timezone *tz); extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode); extern int cap_ptrace_traceme(struct task_struct *parent); @@ -1195,9 +1196,12 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @permitted contains the permitted capability set. * Return 0 and update @new if permission is granted. * @capable: - * Check whether the @tsk process has the @cap capability. + * Check whether the @tsk process has the @cap capability in the indicated + * credentials. * @tsk contains the task_struct for the process. + * @cred contains the credentials to use. * @cap contains the capability <include/linux/capability.h>. + * @audit: Whether to write an audit message or not * Return 0 if the capability is granted for @tsk. * @acct: * Check permission before enabling or disabling process accounting. If @@ -1290,7 +1294,8 @@ struct security_operations { const kernel_cap_t *effective, const kernel_cap_t *inheritable, const kernel_cap_t *permitted); - int (*capable) (struct task_struct *tsk, int cap, int audit); + int (*capable) (struct task_struct *tsk, const struct cred *cred, + int cap, int audit); int (*acct) (struct file *file); int (*sysctl) (struct ctl_table *table, int op); int (*quotactl) (int cmds, int type, int id, struct super_block *sb); @@ -1556,8 +1561,9 @@ int security_capset(struct cred *new, const struct cred *old, const kernel_cap_t *effective, const kernel_cap_t *inheritable, const kernel_cap_t *permitted); -int security_capable(struct task_struct *tsk, int cap); -int security_capable_noaudit(struct task_struct *tsk, int cap); +int security_capable(int cap); +int security_real_capable(struct task_struct *tsk, int cap); +int security_real_capable_noaudit(struct task_struct *tsk, int cap); int security_acct(struct file *file); int security_sysctl(struct ctl_table *table, int op); int security_quotactl(int cmds, int type, int id, struct super_block *sb); @@ -1754,14 +1760,31 @@ static inline int security_capset(struct cred *new, return cap_capset(new, old, effective, inheritable, permitted); } -static inline int security_capable(struct task_struct *tsk, int cap) +static inline int security_capable(int cap) { - return cap_capable(tsk, cap, SECURITY_CAP_AUDIT); + return cap_capable(current, current_cred(), cap, SECURITY_CAP_AUDIT); } -static inline int security_capable_noaudit(struct task_struct *tsk, int cap) +static inline int security_real_capable(struct task_struct *tsk, int cap) { - return cap_capable(tsk, cap, SECURITY_CAP_NOAUDIT); + int ret; + + rcu_read_lock(); + ret = cap_capable(tsk, __task_cred(tsk), cap, SECURITY_CAP_AUDIT); + rcu_read_unlock(); + return ret; +} + +static inline +int security_real_capable_noaudit(struct task_struct *tsk, int cap) +{ + int ret; + + rcu_read_lock(); + ret = cap_capable(tsk, __task_cred(tsk), cap, + SECURITY_CAP_NOAUDIT); + rcu_read_unlock(); + return ret; } static inline int security_acct(struct file *file) diff --git a/kernel/capability.c b/kernel/capability.c index 36b4b4d..df62f53 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -308,7 +308,7 @@ int capable(int cap) BUG(); } - if (has_capability(current, cap)) { + if (security_capable(cap) == 0) { current->flags |= PF_SUPERPRIV; return 1; } diff --git a/security/commoncap.c b/security/commoncap.c index 7971354..f0e671d 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -45,26 +45,22 @@ EXPORT_SYMBOL(cap_netlink_recv); /** * cap_capable - 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 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. + * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable() + * and has_capability() functions. That is, it has the reverse semantics: + * cap_has_capability() returns 0 when a task has a capability, but the + * kernel's capable() and has_capability() returns 1 for this case. */ -int cap_capable(struct task_struct *tsk, int cap, int audit) +int cap_capable(struct task_struct *tsk, const struct cred *cred, int cap, + int audit) { - __u32 cap_raised; - - /* 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; + return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM; } /** @@ -160,7 +156,8 @@ 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(current, current_cred(), CAP_SETPCAP, + SECURITY_CAP_AUDIT) == 0) return 0; #endif return 1; @@ -869,7 +866,8 @@ 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(current, current_cred(), CAP_SETPCAP, + SECURITY_CAP_AUDIT) != 0) /*[4]*/ /* * [1] no changing of bits that are locked * [2] no unlocking of locks @@ -950,7 +948,8 @@ 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(current, current_cred(), CAP_SYS_ADMIN, + SECURITY_CAP_NOAUDIT) == 0) cap_sys_admin = 1; return __vm_enough_memory(mm, pages, cap_sys_admin); } diff --git a/security/security.c b/security/security.c index d85dbb3..a02f243 100644 --- a/security/security.c +++ b/security/security.c @@ -154,14 +154,32 @@ int security_capset(struct cred *new, const struct cred *old, effective, inheritable, permitted); } -int security_capable(struct task_struct *tsk, int cap) +int security_capable(int cap) { - return security_ops->capable(tsk, cap, SECURITY_CAP_AUDIT); + return security_ops->capable(current, current_cred(), cap, + SECURITY_CAP_AUDIT); } -int security_capable_noaudit(struct task_struct *tsk, int cap) +int security_real_capable(struct task_struct *tsk, int cap) { - return security_ops->capable(tsk, cap, SECURITY_CAP_NOAUDIT); + const struct cred *cred; + int ret; + + cred = get_task_cred(tsk); + ret = security_ops->capable(tsk, cred, cap, SECURITY_CAP_AUDIT); + put_cred(cred); + return ret; +} + +int security_real_capable_noaudit(struct task_struct *tsk, int cap) +{ + const struct cred *cred; + int ret; + + cred = get_task_cred(tsk); + ret = security_ops->capable(tsk, cred, cap, SECURITY_CAP_NOAUDIT); + put_cred(cred); + return ret; } int security_acct(struct file *file) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index df30a75..0081597 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1433,12 +1433,13 @@ static int current_has_perm(const struct task_struct *tsk, /* Check whether a task is allowed to use a capability. */ static int task_has_capability(struct task_struct *tsk, + const struct cred *cred, int cap, int audit) { struct avc_audit_data ad; struct av_decision avd; u16 sclass; - u32 sid = task_sid(tsk); + u32 sid = cred_sid(cred); u32 av = CAP_TO_MASK(cap); int rc; @@ -1865,15 +1866,16 @@ static int selinux_capset(struct cred *new, const struct cred *old, return cred_has_perm(old, new, PROCESS__SETCAP); } -static int selinux_capable(struct task_struct *tsk, int cap, int audit) +static int selinux_capable(struct task_struct *tsk, const struct cred *cred, + int cap, int audit) { int rc; - rc = secondary_ops->capable(tsk, cap, audit); + rc = secondary_ops->capable(tsk, cred, cap, audit); if (rc) return rc; - return task_has_capability(tsk, cap, audit); + return task_has_capability(tsk, cred, cap, audit); } static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid) @@ -2037,7 +2039,8 @@ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) { int rc, cap_sys_admin = 0; - rc = selinux_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT); + rc = selinux_capable(current, current_cred(), CAP_SYS_ADMIN, + SECURITY_CAP_NOAUDIT); if (rc == 0) cap_sys_admin = 1; @@ -2880,7 +2883,8 @@ static int selinux_inode_getsecurity(const struct inode *inode, const char *name * and lack of permission just means that we fall back to the * in-core context value, not a denial. */ - error = selinux_capable(current, CAP_MAC_ADMIN, SECURITY_CAP_NOAUDIT); + error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN, + SECURITY_CAP_NOAUDIT); if (!error) error = security_sid_to_context_force(isec->sid, &context, &size); |
