From 1feaa96e5f1907c4d6c306f20bb19e11f63d65cf Mon Sep 17 00:00:00 2001 From: Nikita Kiryushin Date: Tue, 25 Jun 2024 21:08:21 +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) Conflicts: kernel/rcu/tasks.h [yyl: adjust context] 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 8b51e6a5b386..d2b7c3b6ae2d 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1209,7 +1209,7 @@ static void show_rcu_tasks_trace_gp_kthread(void) { char buf[64]; - sprintf(buf, "N%d h:%lu/%lu/%lu", atomic_read(&trc_n_readers_need_end), + snprintf(buf, sizeof(buf), "N%d h:%lu/%lu/%lu", atomic_read(&trc_n_readers_need_end), data_race(n_heavy_reader_ofl_updates), data_race(n_heavy_reader_updates), data_race(n_heavy_reader_attempts)); -- Gitee