In function con_init(), the pointer variable vc_cons[currcons].d, vc and
vc->vc_screenbuf is allocated by kzalloc(). And they are used in the
following codes. However, kzalloc() returns NULL when fails, and null
pointer dereference may happen. And it will cause the kernel to crash.
Therefore, we should check the return value and handle the error.
Further, since the allcoation is in a loop, we should free all the
allocated memory in a loop.
Signed-off-by: Gen Zhang <blackgod016...@gmail.com>
Reviewed-by: Nicolas Pitre <n...@fluxnic.net>
---
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index fdd12f8..d50f68f 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3350,10 +3350,14 @@ static int __init con_init(void)
for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data),
GFP_NOWAIT);
+ if (!vc)
+ goto fail1;
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);
+ if (!vc->vc_screenbuf)
+ goto fail2;
vc_init(vc, vc->vc_rows, vc->vc_cols,
currcons || !vc->vc_sw->con_save_screen);
}
@@ -3375,6 +3379,16 @@ static int __init con_init(void)
register_console(&vt_console_driver);
#endif
return 0;
+fail1:
+ while (currcons > 0) {
+ currcons--;
+ kfree(vc_cons[currcons].d->vc_screenbuf);
+fail2:
+ kfree(vc_cons[currcons].d);
+ vc_cons[currcons].d = NULL;
+ }
+ console_unlock();
+ return -ENOMEM;
}
console_initcall(con_init);
---
