X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=kernel%2Ffork.c;h=e53770d2bf956bf5bf6ec1a42c75121552713da6;hb=1132d5e7b64445b3fa3cb982e6723e33318f7655;hp=aa1076c5e4a9f3a5d9e6f58fef1c6f34e332de8c;hpb=a1858df975edf6706e7a5a3ae000e52d81076807;p=karo-tx-linux.git

diff --git a/kernel/fork.c b/kernel/fork.c
index aa1076c5e4a9..e53770d2bf95 100644
--- 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