On Sun, May 03, 2020 at 03:20:50PM +0800, Dongyang Zhan wrote: > Hi, > > I am a security researcher, my name is Dongyang Zhan. I found a potential bug. > > I hope you can help me to confirm it. > > Thank you. > > In Linux 4.10.17, function con_init() in /drivers/tty/vt/vt.c forgets > to handle the failure of the memory allocation operation (e.g., > vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), > GFP_NOWAIT)). > > Source code and comments； > vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT); > INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK); > tty_port_init(&vc->port); > visual_init(vc, currcons, 1); > vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT); > vc_init(vc, vc->vc_rows, vc->vc_cols, > currcons || !vc->vc_sw->con_save_screen); > > If the allocation fails, dereferencing vc will cause a null pointer dereference. But that allocation can not fail, so all is fine. thanks, greg k-h
