security,selinux,smack: kill security_task_wait hook

As reported by yangshukui, a permission denial from security_task_wait()
can lead to a soft lockup in zap_pid_ns_processes() since it only expects
sys_wait4() to return 0 or -ECHILD. Further, security_task_wait() can
in general lead to zombies; in the absence of some way to automatically
reparent a child process upon a denial, the hook is not useful.  Remove
the security hook and its implementations in SELinux and Smack.  Smack
already removed its check from its hook.

Reported-by: yangshukui <yangshukui@huawei.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Stephen Smalley
2017-01-10 12:28:32 -05:00
committed by Paul Moore
parent b4ba35c75a
commit 3a2f5a59a6
6 changed files with 2 additions and 63 deletions

View File

@@ -332,7 +332,6 @@ 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 security_task_wait(struct task_struct *p);
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);
@@ -980,11 +979,6 @@ static inline int security_task_kill(struct task_struct *p,
return 0;
}
static inline int security_task_wait(struct task_struct *p)
{
return 0;
}
static inline int security_task_prctl(int option, unsigned long arg2,
unsigned long arg3,
unsigned long arg4,