1 files changed, 7 insertions, 3 deletions

diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
index b13d058f8c34..09522573f611 100644
--- a/net/bpfilter/bpfilter_kern.c
+++ b/net/bpfilter/bpfilter_kern.c
@@ -24,17 +24,19 @@ static void shutdown_umh(struct umh_info *info)
 {
         struct task_struct *tsk;
 
+        if (!info->pid)
+                return;
         tsk = pid_task(find_vpid(info->pid), PIDTYPE_PID);
         if (tsk)
                 force_sig(SIGKILL, tsk);
         fput(info->pipe_to_umh);
         fput(info->pipe_from_umh);
+        info->pid = 0;
 }
 
 static void __stop_umh(void)
 {
-        if (IS_ENABLED(CONFIG_INET) &&
-            bpfilter_process_sockopt) {
+        if (IS_ENABLED(CONFIG_INET)) {
                 bpfilter_process_sockopt = NULL;
                 shutdown_umh(&info);
         }
@@ -55,7 +57,7 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname,
         struct mbox_reply reply;
         loff_t pos;
         ssize_t n;
-        int ret;
+        int ret = -EFAULT;
 
         req.is_set = is_set;
         req.pid = current->pid;
@@ -63,6 +65,8 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname,
         req.addr = (long)optval;
         req.len = optlen;
         mutex_lock(&bpfilter_lock);
+        if (!info.pid)
+                goto out;
         n = __kernel_write(info.pipe_to_umh, &req, sizeof(req), &pos);
         if (n != sizeof(req)) {
                 pr_err("write fail %zd\n", n);