Fwd: Possible null pointer dereference in con_init()

[Dongyang Zhan <zdyzztq@xxxxxxxxx>]

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.