[PATCH] SELinux: extend task_kill hook to handle signals sent by AIO completion
This patch extends the security_task_kill hook to handle signals sent by AIO
completion. In this case, the secid of the task responsible for the signal
needs to be obtained and saved earlier, so a security_task_getsecid() hook is
added, and then this saved value is passed subsequently to the extended
task_kill hook for use in checking.
Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index b85afcf..a5189a3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2644,6 +2644,11 @@
return task_has_perm(current, p, PROCESS__GETSESSION);
}
+static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
+{
+ selinux_get_task_sid(p, secid);
+}
+
static int selinux_task_setgroups(struct group_info *group_info)
{
/* See the comment for setuid above. */
@@ -2700,12 +2705,14 @@
return task_has_perm(current, p, PROCESS__SETSCHED);
}
-static int selinux_task_kill(struct task_struct *p, struct siginfo *info, int sig)
+static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
+ int sig, u32 secid)
{
u32 perm;
int rc;
+ struct task_security_struct *tsec;
- rc = secondary_ops->task_kill(p, info, sig);
+ rc = secondary_ops->task_kill(p, info, sig, secid);
if (rc)
return rc;
@@ -2716,8 +2723,12 @@
perm = PROCESS__SIGNULL; /* null signal; existence test */
else
perm = signal_to_av(sig);
-
- return task_has_perm(current, p, perm);
+ tsec = p->security;
+ if (secid)
+ rc = avc_has_perm(secid, tsec->sid, SECCLASS_PROCESS, perm, NULL);
+ else
+ rc = task_has_perm(current, p, perm);
+ return rc;
}
static int selinux_task_prctl(int option,
@@ -4434,6 +4445,7 @@
.task_setpgid = selinux_task_setpgid,
.task_getpgid = selinux_task_getpgid,
.task_getsid = selinux_task_getsid,
+ .task_getsecid = selinux_task_getsecid,
.task_setgroups = selinux_task_setgroups,
.task_setnice = selinux_task_setnice,
.task_setioprio = selinux_task_setioprio,