6.6-stable review patch. If anyone has any objections, please let me know.
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From: Yongzhen Zhang zhangyongzhen@kylinos.cn
[ Upstream commit 523b84dc7ccea9c4d79126d6ed1cf9033cf83b05 ]
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 zhangyongzhen@kylinos.cn Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Sasha Levin sashal@kernel.org --- 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 52bd3af54369..942b942f6bf9 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -943,6 +943,9 @@ 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);