Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[karo-tx-linux.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index aa1076c5e4a9f3a5d9e6f58fef1c6f34e332de8c..e53770d2bf956bf5bf6ec1a42c75121552713da6 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1577,6 +1577,18 @@ static __latent_entropy struct task_struct *copy_process(
        if (!p)
                goto fork_out;
 
+       /*
+        * This _must_ happen before we call free_task(), i.e. before we jump
+        * to any of the bad_fork_* labels. This is to avoid freeing
+        * p->set_child_tid which is (ab)used as a kthread's data pointer for
+        * kernel threads (PF_KTHREAD).
+        */
+       p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
+       /*
+        * Clear TID on mm_release()?
+        */
+       p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
+
        ftrace_graph_init_task(p);
 
        rt_mutex_init_task(p);
@@ -1743,11 +1755,6 @@ static __latent_entropy struct task_struct *copy_process(
                }
        }
 
-       p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
-       /*
-        * Clear TID on mm_release()?
-        */
-       p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
 #ifdef CONFIG_BLOCK
        p->plug = NULL;
 #endif