[Fwd: [PATCH] usb,signal,security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill]

---
 drivers/usb/core/devio.c     | 10 ++--------
 include/linux/lsm_hooks.h    |  5 +++--
 include/linux/sched/signal.h |  2 +-
 include/linux/security.h     |  4 ++--
 kernel/signal.c              |  6 +++---
 security/apparmor/lsm.c      | 17 ++++++++++++-----
 security/security.c          |  4 ++--
 security/selinux/hooks.c     |  7 +++++--
 security/smack/smack_lsm.c   | 12 +++++-------
 9 files changed, 35 insertions(+), 32 deletions(-)

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index ebe2759..b44f74c 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c

@@ -78,7 +78,6 @@ struct usb_dev_state {
 	const struct cred *cred;
 	void __user *disccontext;
 	unsigned long ifclaimed;
-	u32 secid;
 	u32 disabled_bulk_eps;
 	bool privileges_dropped;
 	unsigned long interface_allowed_mask;

@@ -108,7 +107,6 @@ struct async {
 	struct usb_memory *usbm;
 	unsigned int mem_usage;
 	int status;
-	u32 secid;
 	u8 bulk_addr;
 	u8 bulk_status;
 };

@@ -596,7 +594,6 @@ static void async_completed(struct urb *urb)
 	struct usb_dev_state *ps = as->ps;
 	struct siginfo sinfo;
 	struct pid *pid = NULL;
-	u32 secid = 0;
 	const struct cred *cred = NULL;
 	int signr;
 

@@ -612,7 +609,6 @@ static void async_completed(struct urb *urb)
 		sinfo.si_addr = as->userurb;
 		pid = get_pid(as->pid);
 		cred = get_cred(as->cred);
-		secid = as->secid;
 	}
 	snoop(&urb->dev->dev, "urb complete\n");
 	snoop_urb(urb->dev, as->userurb, urb->pipe, urb-

quoted

actual_length,

@@ -626,7 +622,7 @@ static void async_completed(struct urb *urb)
 	spin_unlock(&ps->lock);
 
 	if (signr) {
-		kill_pid_info_as_cred(sinfo.si_signo, &sinfo, pid,

cred, secid);
+		kill_pid_info_as_cred(sinfo.si_signo, &sinfo, pid,
cred);
 		put_pid(pid);
 		put_cred(cred);
 	}

@@ -1023,7 +1019,6 @@ static int usbdev_open(struct inode *inode,

struct file *file)
 	init_waitqueue_head(&ps->wait);
 	ps->disc_pid = get_pid(task_pid(current));
 	ps->cred = get_current_cred();
-	security_task_getsecid(current, &ps->secid);
 	smp_wmb();
 	list_add_tail(&ps->list, &dev->filelist);
 	file->private_data = ps;

@@ -1733,7 +1728,6 @@ static int proc_do_submiturb(struct usb_dev_state

*ps, struct usbdevfs_urb *uurb
 	as->ifnum = ifnum;
 	as->pid = get_pid(task_pid(current));
 	as->cred = get_current_cred();
-	security_task_getsecid(current, &as->secid);
 	snoop_urb(ps->dev, as->userurb, as->urb->pipe,
 			as->urb->transfer_buffer_length, 0, SUBMIT,
 			NULL, 0);

@@ -2609,7 +2603,7 @@ static void usbdev_remove(struct usb_device

*udev)
 			sinfo.si_code = SI_ASYNCIO;
 			sinfo.si_addr = ps->disccontext;
 			kill_pid_info_as_cred(ps->discsignr, &sinfo,
-					ps->disc_pid, ps->cred, ps-

quoted

secid);

+					ps->disc_pid, ps->cred);
 		}
 	}
 }

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index ce02f76..b0b663b2 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h

@@ -674,7 +674,8 @@
  *	@p contains the task_struct for process.
  *	@info contains the signal information.
  *	@sig contains the signal value.
- *	@secid contains the sid of the process where the signal

originated
+ *	@cred contains the cred of the process where the signal
originated, or
+ *	NULL if the current task is the originator.
  *	Return 0 if permission is granted.
  * @task_prctl:
  *	Check permission before performing a process control
operation on the

@@ -1533,7 +1534,7 @@ union security_list_options {
 	int (*task_getscheduler)(struct task_struct *p);
 	int (*task_movememory)(struct task_struct *p);
 	int (*task_kill)(struct task_struct *p, struct siginfo *info,
-				int sig, u32 secid);
+				int sig, const struct cred *cred);
 	int (*task_prctl)(int option, unsigned long arg2, unsigned

long arg3,
 				unsigned long arg4, unsigned long
arg5);
 	void (*task_to_inode)(struct task_struct *p, struct inode
*inode);

diff --git a/include/linux/sched/signal.h

b/include/linux/sched/signal.h
index 2a0dd40..ae4fe12 100644

--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h

@@ -290,7 +290,7 @@ extern int force_sig_info(int, struct siginfo *,

struct task_struct *);
 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid
*pgrp);
 extern int kill_pid_info(int sig, struct siginfo *info, struct pid
*pid);
 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
-				const struct cred *, u32);
+				const struct cred *);
 extern int kill_pgrp(struct pid *pid, int sig, int priv);
 extern int kill_pid(struct pid *pid, int sig, int priv);
 extern __must_check bool do_notify_parent(struct task_struct *, int);

diff --git a/include/linux/security.h b/include/linux/security.h
index 458e24b..9655621 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h

@@ -347,7 +347,7 @@ int security_task_setscheduler(struct task_struct

*p);
 int security_task_getscheduler(struct task_struct *p);
 int security_task_movememory(struct task_struct *p);
 int security_task_kill(struct task_struct *p, struct siginfo *info,
-			int sig, u32 secid);
+			int sig, const struct cred *cred);
 int security_task_prctl(int option, unsigned long arg2, unsigned long
arg3,
 			unsigned long arg4, unsigned long arg5);
 void security_task_to_inode(struct task_struct *p, struct inode
*inode);

@@ -1015,7 +1015,7 @@ static inline int security_task_movememory(struct

task_struct *p)
 
 static inline int security_task_kill(struct task_struct *p,
 				     struct siginfo *info, int sig,
-				     u32 secid)
+				     const struct cred *cred)
 {
 	return 0;
 }

diff --git a/kernel/signal.c b/kernel/signal.c
index caed913..a397bb9 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c

@@ -762,7 +762,7 @@ static int check_kill_permission(int sig, struct

siginfo *info,
 		}
 	}
 
-	return security_task_kill(t, info, sig, 0);
+	return security_task_kill(t, info, sig, NULL);
 }
 
 /**

@@ -1348,7 +1348,7 @@ static int kill_as_cred_perm(const struct cred

*cred,
 
 /* like kill_pid_info(), but doesn't use uid/euid of "current" */
 int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid
*pid,
-			 const struct cred *cred, u32 secid)
+			 const struct cred *cred)
 {
 	int ret = -EINVAL;
 	struct task_struct *p;

@@ -1367,7 +1367,7 @@ int kill_pid_info_as_cred(int sig, struct siginfo

*info, struct pid *pid,
 		ret = -EPERM;
 		goto out_unlock;
 	}
-	ret = security_task_kill(p, info, sig, secid);
+	ret = security_task_kill(p, info, sig, cred);
 	if (ret)
 		goto out_unlock;
 

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index cc5ab23..2fbec6d 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c

@@ -718,16 +718,23 @@ static int apparmor_task_setrlimit(struct

task_struct *task,
 }
 
 static int apparmor_task_kill(struct task_struct *target, struct
siginfo *info,
-			      int sig, u32 secid)
+			      int sig, const struct cred *cred)
 {
 	struct aa_label *cl, *tl;
 	int error;
 
-	if (secid)
-		/* TODO: after secid to label mapping is done.
-		 *  Dealing with USB IO specific behavior
+	if (cred) {
+		/*
+		 * Dealing with USB IO specific behavior
 		 */
-		return 0;
+		cl = aa_get_newest_cred_label(cred);
+		tl = aa_get_task_label(target);
+		error = aa_may_signal(cl, tl, sig);
+		aa_put_label(cl);
+		aa_put_label(tl);
+		return error;
+	}
+
 	cl = __begin_current_label_crit_section();
 	tl = aa_get_task_label(target);
 	error = aa_may_signal(cl, tl, sig);

diff --git a/security/security.c b/security/security.c
index 55b5997..3b67842 100644
--- a/security/security.c
+++ b/security/security.c

@@ -1118,9 +1118,9 @@ int security_task_movememory(struct task_struct

*p)
 }
 
 int security_task_kill(struct task_struct *p, struct siginfo *info,
-			int sig, u32 secid)
+			int sig, const struct cred *cred)
 {
-	return call_int_hook(task_kill, 0, p, info, sig, secid);
+	return call_int_hook(task_kill, 0, p, info, sig, cred);
 }
 
 int security_task_prctl(int option, unsigned long arg2, unsigned long
arg3,

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 45943e1..68bc634 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c

@@ -4041,16 +4041,19 @@ static int selinux_task_movememory(struct

task_struct *p)
 }
 
 static int selinux_task_kill(struct task_struct *p, struct siginfo
*info,
-				int sig, u32 secid)
+				int sig, const struct cred *cred)
 {
+	u32 secid;
 	u32 perm;
 
 	if (!sig)
 		perm = PROCESS__SIGNULL; /* null signal; existence
test */
 	else
 		perm = signal_to_av(sig);
-	if (!secid)
+	if (!cred)
 		secid = current_sid();
+	else
+		secid = cred_sid(cred);
 	return avc_has_perm(secid, task_sid(p), SECCLASS_PROCESS,
perm, NULL);
 }
 

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 463af86..65fcede 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c

@@ -2259,15 +2259,13 @@ static int smack_task_movememory(struct

task_struct *p)
  * @p: the task object
  * @info: unused
  * @sig: unused
- * @secid: identifies the smack to use in lieu of current's
+ * @cred: identifies the cred to use in lieu of current's
  *
  * Return 0 if write access is permitted
  *
- * The secid behavior is an artifact of an SELinux hack
- * in the USB code. Someday it may go away.
  */
 static int smack_task_kill(struct task_struct *p, struct siginfo
*info,
-			   int sig, u32 secid)
+			   int sig, const struct cred *cred)
 {
 	struct smk_audit_info ad;
 	struct smack_known *skp;

@@ -2283,17 +2281,17 @@ static int smack_task_kill(struct task_struct

*p, struct siginfo *info,
 	 * Sending a signal requires that the sender
 	 * can write the receiver.
 	 */
-	if (secid == 0) {
+	if (cred == NULL) {
 		rc = smk_curacc(tkp, MAY_DELIVER, &ad);
 		rc = smk_bu_task(p, MAY_DELIVER, rc);
 		return rc;
 	}
 	/*
-	 * If the secid isn't 0 we're dealing with some USB IO
+	 * If the cred isn't NULL we're dealing with some USB IO
 	 * specific behavior. This is not clean. For one thing
 	 * we can't take privilege into account.
 	 */
-	skp = smack_from_secid(secid);
+	skp = smk_of_task(cred->security);
 	rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
 	rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
 	return rc;
-- 
2.9.4