4 files changed, 43 insertions, 2 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 89541d248893..e35e35b9fc48 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1406,6 +1406,7 @@ extern struct pid *cad_pid;
 #define PF_RANDOMIZE            0x00400000      /* Randomize virtual address space */
 #define PF_SWAPWRITE            0x00800000      /* Allowed to write to swap */
 #define PF_MEMSTALL             0x01000000      /* Stalled due to lack of memory */
+#define PF_UMH                  0x02000000      /* I'm an Usermodehelper process */
 #define PF_NO_SETAFFINITY       0x04000000      /* Userland is not allowed to meddle with cpus_allowed */
 #define PF_MCE_EARLY            0x08000000      /* Early kill for mce process policy */
 #define PF_MUTEX_TESTER         0x20000000      /* Thread belongs to the rt mutex tester */
@@ -1904,6 +1905,14 @@ static inline void rseq_execve(struct task_struct *t)
 
 #endif
 
+void __exit_umh(struct task_struct *tsk);
+
+static inline void exit_umh(struct task_struct *tsk)
+{
+        if (unlikely(tsk->flags & PF_UMH))
+                __exit_umh(tsk);
+}
+
 #ifdef CONFIG_DEBUG_RSEQ
 
 void rseq_syscall(struct pt_regs *regs);
diff --git a/include/linux/umh.h b/include/linux/umh.h
index 235f51b62c71..0c08de356d0d 100644
--- a/include/linux/umh.h
+++ b/include/linux/umh.h
@@ -47,6 +47,8 @@ struct umh_info {
         const char *cmdline;
         struct file *pipe_to_umh;
         struct file *pipe_from_umh;
+        struct list_head list;
+        void (*cleanup)(struct umh_info *info);
         pid_t pid;
 };
 int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
diff --git a/kernel/exit.c b/kernel/exit.c
index 8a01b671dc1f..dad70419195c 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -866,6 +866,7 @@ void __noreturn do_exit(long code)
         exit_task_namespaces(tsk);
         exit_task_work(tsk);
         exit_thread(tsk);
+        exit_umh(tsk);
 
         /*
          * Flush inherited counters to the parent - before the parent
diff --git a/kernel/umh.c b/kernel/umh.c
index 0baa672e023c..d937cbad903a 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -37,6 +37,8 @@ static kernel_cap_t usermodehelper_bset = CAP_FULL_SET;
 static kernel_cap_t usermodehelper_inheritable = CAP_FULL_SET;
 static DEFINE_SPINLOCK(umh_sysctl_lock);
 static DECLARE_RWSEM(umhelper_sem);
+static LIST_HEAD(umh_list);
+static DEFINE_MUTEX(umh_list_lock);
 
 static void call_usermodehelper_freeinfo(struct subprocess_info *info)
 {
@@ -100,10 +102,12 @@ static int call_usermodehelper_exec_async(void *data)
         commit_creds(new);
 
         sub_info->pid = task_pid_nr(current);
-        if (sub_info->file)
+        if (sub_info->file) {
                 retval = do_execve_file(sub_info->file,
                                         sub_info->argv, sub_info->envp);
-        else
+                if (!retval)
+                        current->flags |= PF_UMH;
+        } else
                 retval = do_execve(getname_kernel(sub_info->path),
                                    (const char __user *const __user *)sub_info->argv,
                                    (const char __user *const __user *)sub_info->envp);
@@ -517,6 +521,11 @@ int fork_usermode_blob(void *data, size_t len, struct umh_info *info)
                 goto out;
 
         err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
+        if (!err) {
+                mutex_lock(&umh_list_lock);
+                list_add(&info->list, &umh_list);
+                mutex_unlock(&umh_list_lock);
+        }
 out:
         fput(file);
         return err;
@@ -679,6 +688,26 @@ static int proc_cap_handler(struct ctl_table *table, int write,
         return 0;
 }
 
+void __exit_umh(struct task_struct *tsk)
+{
+        struct umh_info *info;
+        pid_t pid = tsk->pid;
+
+        mutex_lock(&umh_list_lock);
+        list_for_each_entry(info, &umh_list, list) {
+                if (info->pid == pid) {
+                        list_del(&info->list);
+                        mutex_unlock(&umh_list_lock);
+                        goto out;
+                }
+        }
+        mutex_unlock(&umh_list_lock);
+        return;
+out:
+        if (info->cleanup)
+                info->cleanup(info);
+}
+
 struct ctl_table usermodehelper_table[] = {
         {
                 .procname       = "bset",