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| author | Stephen Smalley <sds@tycho.nsa.gov> | 2017-01-10 20:28:32 +0300 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2017-01-12 19:10:57 +0300 |
| commit | 3a2f5a59a695a73e0cde9a61e0feae5fa730e936 (patch) | |
| tree | 058704d18e909a2c0b46356c74d3c1156c2206aa /kernel/exit.c | |
| parent | b4ba35c75a0671a06b978b6386b54148efddf39f (diff) | |
| download | linux-3a2f5a59a695a73e0cde9a61e0feae5fa730e936.tar.xz | |
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 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 19 |
1 files changed, 2 insertions, 17 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 8f14b866f9f6..60f245190571 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -14,7 +14,6 @@ #include <linux/tty.h> #include <linux/iocontext.h> #include <linux/key.h> -#include <linux/security.h> #include <linux/cpu.h> #include <linux/acct.h> #include <linux/tsacct_kern.h> @@ -1360,7 +1359,7 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p) * Returns nonzero for a final return, when we have unlocked tasklist_lock. * Returns zero if the search for a child should continue; * then ->notask_error is 0 if @p is an eligible child, - * or another error from security_task_wait(), or still -ECHILD. + * or still -ECHILD. */ static int wait_consider_task(struct wait_opts *wo, int ptrace, struct task_struct *p) @@ -1380,20 +1379,6 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, if (!ret) return ret; - ret = security_task_wait(p); - if (unlikely(ret < 0)) { - /* - * If we have not yet seen any eligible child, - * then let this error code replace -ECHILD. - * A permission error will give the user a clue - * to look for security policy problems, rather - * than for mysterious wait bugs. - */ - if (wo->notask_error) - wo->notask_error = ret; - return 0; - } - if (unlikely(exit_state == EXIT_TRACE)) { /* * ptrace == 0 means we are the natural parent. In this case @@ -1486,7 +1471,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, * Returns nonzero for a final return, when we have unlocked tasklist_lock. * Returns zero if the search for a child should continue; then * ->notask_error is 0 if there were any eligible children, - * or another error from security_task_wait(), or still -ECHILD. + * or still -ECHILD. */ static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk) { |