[PATCH] sched/core: Replace sprintf() with scnprintf() in init_idle()

[PATCH] sched/core: Replace sprintf() with scnprintf() in init_idle()

[Ziran Zhang]

The kernel documentation notes that sprintf() is deprecated and unsafe.
Replace the deprecated sprintf() with the bounded scnprintf() when
formatting the idle task's comm.  This prevents a potential buffer
overflow if INIT_TASK_COMM or the CPU number ever grow beyond the
remaining space in the 16‑byte comm field.

Signed-off-by: Ziran Zhang <zhangcoder@yeah.net>
---
 kernel/sched/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a2f86807f..215b241af 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8302,7 +8302,7 @@ void __init init_idle(struct task_struct *idle, int cpu)
 	idle->sched_class = &idle_sched_class;
 	ftrace_graph_init_idle_task(idle, cpu);
 	vtime_init_idle(idle, cpu);
-	sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
+	scnprintf(idle->comm, sizeof(idle->comm), "%s/%d", INIT_TASK_COMM, cpu);
 }
 
 int cpuset_cpumask_can_shrink(const struct cpumask *cur,
-- 
2.43.0