misc/libmasm/module: Fix two use after free in ibmasm_init_one

stable inclusion
from stable-v4.19.198
commit 481a76d4749ee3a27f902ba213fdcbb4bb39720e
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RLTD
CVE: CVE-2021-47334

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=481a76d4749ee3a27f902ba213fdcbb4bb39720e



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[ Upstream commit 7272b591 ]

In ibmasm_init_one, it calls ibmasm_init_remote_input_dev().
Inside ibmasm_init_remote_input_dev, mouse_dev and keybd_dev are
allocated by input_allocate_device(), and assigned to
sp->remote.mouse_dev and sp->remote.keybd_dev respectively.

In the err_free_devices error branch of ibmasm_init_one,
mouse_dev and keybd_dev are freed by input_free_device(), and return
error. Then the execution runs into error_send_message error branch
of ibmasm_init_one, where ibmasm_free_remote_input_dev(sp) is called
to unregister the freed sp->remote.mouse_dev and sp->remote.keybd_dev.

My patch add a "error_init_remote" label to handle the error of
ibmasm_init_remote_input_dev(), to avoid the uaf bugs.

Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Link: https://lore.kernel.org/r/20210426170620.10546-1-lyl2019@mail.ustc.edu.cn


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>