ipack: ipoctal: fix stack information leak

stable inclusion
from stable-v5.10.71
commit 5f6a309a699675680df15d9b6d389114515b4426
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4NI
CVE: CVE-2021-47401

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5f6a309a699675680df15d9b6d389114515b4426



--------------------------------

commit a89936cc upstream.

The tty driver name is used also after registering the driver and must
specifically not be allocated on the stack to avoid leaking information
to user space (or triggering an oops).

Drivers should not try to encode topology information in the tty device
name but this one snuck in through staging without anyone noticing and
another driver has since copied this malpractice.

Fixing the ABI is a separate issue, but this at least plugs the security
hole.

Fixes: ba4dc61f ("Staging: ipack: add support for IP-OCTAL mezzanine board")
Cc: stable@vger.kernel.org      # 3.5
Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210917114622.5412-2-johan@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>