Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux...

[mirror_ubuntu-bionic-kernel.git] / fs / proc / base.c

diff --git a/fs/proc/base.c b/fs/proc/base.c
index b1f7d30e96c27aa5d3e2a9abe0052e123087a448..3d773eb9e14476fb4035773e6666f84f813f8369 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2488,6 +2488,12 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
        length = -ESRCH;
        if (!task)
                goto out_no_task;
+
+       /* A task may only write its own attributes. */
+       length = -EACCES;
+       if (current != task)
+               goto out;
+
        if (count > PAGE_SIZE)
                count = PAGE_SIZE;
 
@@ -2503,14 +2509,13 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
        }
 
        /* Guard against adverse ptrace interaction */
-       length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
+       length = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
        if (length < 0)
                goto out_free;
 
-       length = security_setprocattr(task,
-                                     (char*)file->f_path.dentry->d_name.name,
+       length = security_setprocattr(file->f_path.dentry->d_name.name,
                                      page, count);
-       mutex_unlock(&task->signal->cred_guard_mutex);
+       mutex_unlock(&current->signal->cred_guard_mutex);
 out_free:
        kfree(page);
 out: