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| author | Stephen Smalley <sds@tycho.nsa.gov> | 2017-01-10 12:28:32 -0500 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2017-01-12 11:10:57 -0500 |
| commit | 3a2f5a59a695a73e0cde9a61e0feae5fa730e936 (patch) | |
| tree | 058704d18e909a2c0b46356c74d3c1156c2206aa /security/smack/smack_lsm.c | |
| parent | b4ba35c75a0671a06b978b6386b54148efddf39f (diff) | |
| download | linux-3a2f5a59a695a73e0cde9a61e0feae5fa730e936.tar.gz | |
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>
Diffstat (limited to 'security/smack/smack_lsm.c')
| -rw-r--r-- | security/smack/smack_lsm.c | 20 |
1 files changed, 0 insertions, 20 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 8da4a6b9ca4d..2166373ea5a4 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2272,25 +2272,6 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info, } /** - * smack_task_wait - Smack access check for waiting - * @p: task to wait for - * - * Returns 0 - */ -static int smack_task_wait(struct task_struct *p) -{ - /* - * Allow the operation to succeed. - * Zombies are bad. - * In userless environments (e.g. phones) programs - * get marked with SMACK64EXEC and even if the parent - * and child shouldn't be talking the parent still - * may expect to know when the child exits. - */ - return 0; -} - -/** * smack_task_to_inode - copy task smack into the inode blob * @p: task to copy from * @inode: inode to copy to @@ -4658,7 +4639,6 @@ static struct security_hook_list smack_hooks[] = { LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler), LSM_HOOK_INIT(task_movememory, smack_task_movememory), LSM_HOOK_INIT(task_kill, smack_task_kill), - LSM_HOOK_INIT(task_wait, smack_task_wait), LSM_HOOK_INIT(task_to_inode, smack_task_to_inode), LSM_HOOK_INIT(ipc_permission, smack_ipc_permission), |