tty_register_driver: only allocate tty instances when defined
If device->num is zero we attempt to kmalloc() zero bytes. When SLUB is
enabled this returns a null pointer and take that as an allocation failure
and fail the device register. Check for no devices and avoid the
allocation.
[akpm: opportunistic kzalloc() conversion]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 7a32df5..389da36 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -3720,11 +3720,10 @@
if (driver->flags & TTY_DRIVER_INSTALLED)
return 0;
- if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
- p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
+ if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
+ p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
if (!p)
return -ENOMEM;
- memset(p, 0, driver->num * 3 * sizeof(void *));
}
if (!driver->major) {