From 3a20f8146dfd45134e777af681008f390166a1d3 Mon Sep 17 00:00:00 2001 From: Nikita Kiryushin Date: Tue, 25 Jun 2024 21:16:12 +0800 Subject: [PATCH] rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow mainline inclusion from mainline-v6.10-rc1 commit cc5645fddb0ce28492b15520306d092730dffa48 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6SGB CVE: CVE-2024-38577 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc5645fddb0ce28492b15520306d092730dffa48 --------------------------- There is a possibility of buffer overflow in show_rcu_tasks_trace_gp_kthread() if counters, passed to sprintf() are huge. Counter numbers, needed for this are unrealistically high, but buffer overflow is still possible. Use snprintf() with buffer size instead of sprintf(). Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: edf3775f0ad6 ("rcu-tasks: Add count for idle tasks on offline CPUs") Signed-off-by: Nikita Kiryushin Reviewed-by: Steven Rostedt (Google) Signed-off-by: Paul E. McKenney Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Yang Yingliang --- kernel/rcu/tasks.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 65e000ca332c..305e960c08ac 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1938,7 +1938,7 @@ void show_rcu_tasks_trace_gp_kthread(void) { char buf[64]; - sprintf(buf, "N%lu h:%lu/%lu/%lu", + snprintf(buf, sizeof(buf), "N%lu h:%lu/%lu/%lu", data_race(n_trc_holdouts), data_race(n_heavy_reader_ofl_updates), data_race(n_heavy_reader_updates), -- Gitee