Merge branch 'fix/misc' into topic/misc

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/exec.c b/fs/exec.c
index c0c636e34f60..623a5cc3076a 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -923,6 +923,15 @@ char *get_task_comm(char *buf, struct task_struct *tsk)
 void set_task_comm(struct task_struct *tsk, char *buf)
 {
 	task_lock(tsk);
+
+	/*
+	 * Threads may access current->comm without holding
+	 * the task lock, so write the string carefully.
+	 * Readers without a lock may see incomplete new
+	 * names but are safe from non-terminating string reads.
+	 */
+	memset(tsk->comm, 0, TASK_COMM_LEN);
+	wmb();
 	strlcpy(tsk->comm, buf, sizeof(tsk->comm));
 	task_unlock(tsk);
 	perf_event_comm(tsk);