From 523b84dc7ccea9c4d79126d6ed1cf9033cf83b05 Mon Sep 17 00:00:00 2001 From: Yongzhen Zhang Date: Tue, 1 Jul 2025 17:07:04 +0800 Subject: [PATCH] fbdev: fix potential buffer overflow in do_register_framebuffer() The current implementation may lead to buffer overflow when: 1. Unregistration creates NULL gaps in registered_fb[] 2. All array slots become occupied despite num_registered_fb < FB_MAX 3. The registration loop exceeds array bounds Add boundary check to prevent registered_fb[FB_MAX] access. Signed-off-by: Yongzhen Zhang Signed-off-by: Helge Deller --- drivers/video/fbdev/core/fbmem.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index dfcf5e4d1d4cc..53f1719b1ae15 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -449,6 +449,9 @@ static int do_register_framebuffer(struct fb_info *fb_info) if (!registered_fb[i]) break; + if (i >= FB_MAX) + return -ENXIO; + if (!fb_info->modelist.prev || !fb_info->modelist.next) INIT_LIST_HEAD(&fb_info->modelist); -- 2.47.2