[kernel-hardening] [RFC v3 1/2] security: add task argument to security_capable()

[Vasiliy Kulikov <segoon@openwall.com>]

This patch changes security_capable() to use explicit task
argument instead of current.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
---
 drivers/pci/pci-sysfs.c  |    5 ++++-
 include/linux/security.h |    8 ++++----
 kernel/capability.c      |    2 +-
 security/security.c      |    6 +++---
 4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 7bcf12a..bc52c66 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -431,7 +431,10 @@ pci_read_config(struct file *filp, struct kobject *kobj,
 	u8 *data = (u8*) buf;
 
 	/* Several chips lock up trying to read undefined config space */
-	if (security_capable(&init_user_ns, filp->f_cred, CAP_SYS_ADMIN) == 0) {
+	if (security_capable(current,
+			     &init_user_ns,
+			     filp->f_cred,
+			     CAP_SYS_ADMIN) == 0) {
 		size = dev->cfg_size;
 	} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
 		size = 128;
diff --git a/include/linux/security.h b/include/linux/security.h
index 8ce59ef..8509dbf 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1667,8 +1667,8 @@ 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 user_namespace *ns, const struct cred *cred,
-			int cap);
+int security_capable(struct task_struct *task, struct user_namespace *ns,
+		     const struct cred *cred, int cap);
 int security_real_capable(struct task_struct *tsk, struct user_namespace *ns,
 			int cap);
 int security_real_capable_noaudit(struct task_struct *tsk,
@@ -1865,10 +1865,10 @@ static inline int security_capset(struct cred *new,
 	return cap_capset(new, old, effective, inheritable, permitted);
 }
 
-static inline int security_capable(struct user_namespace *ns,
+static inline int security_capable(struct task_struct *task, struct user_namespace *ns,
 				   const struct cred *cred, int cap)
 {
-	return cap_capable(current, cred, ns, cap, SECURITY_CAP_AUDIT);
+	return cap_capable(task, cred, ns, cap, SECURITY_CAP_AUDIT);
 }
 
 static inline int security_real_capable(struct task_struct *tsk, struct user_namespace *ns, int cap)
diff --git a/kernel/capability.c b/kernel/capability.c
index 283c529..91c2278 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -374,7 +374,7 @@ bool ns_capable(struct user_namespace *ns, int cap)
 		BUG();
 	}
 
-	if (security_capable(ns, current_cred(), cap) == 0) {
+	if (security_capable(current, ns, current_cred(), cap) == 0) {
 		current->flags |= PF_SUPERPRIV;
 		return true;
 	}
diff --git a/security/security.c b/security/security.c
index 4ba6d4c..dd16397 100644
--- a/security/security.c
+++ b/security/security.c
@@ -154,10 +154,10 @@ int security_capset(struct cred *new, const struct cred *old,
 				    effective, inheritable, permitted);
 }
 
-int security_capable(struct user_namespace *ns, const struct cred *cred,
-		     int cap)
+int security_capable(struct task_struct *task, struct user_namespace *ns,
+		     const struct cred *cred, int cap)
 {
-	return security_ops->capable(current, cred, ns, cap,
+	return security_ops->capable(task, cred, ns, cap,
 				     SECURITY_CAP_AUDIT);
 }
 
---