Bluetooth: L2CAP: Fix attempting to access uninitialized memory

stable inclusion
from stable-v4.19.265
commit 36919a82f335784d86b4def308739559bb47943d
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5ZNRS


CVE: CVE-2022-42895

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

commit b1a2cd50 upstream.

On l2cap_parse_conf_req the variable efs is only initialized if
remote_efs has been set.

CVE: CVE-2022-42895
CC: stable@vger.kernel.org
Reported-by: Tamás Koczka <poprdi@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Baisong Zhong <zhongbaisong@huawei.com>
Reviewed-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>