Bluetooth: L2CAP: Fix attempting to access uninitialized memory

stable inclusion
from stable-v5.10.154
commit 26ca2ac091b49281d73df86111d16e5a76e43bd7
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5ZNRS
CVE: CVE-2022-42895

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=26ca2ac091b49281d73df86111d16e5a76e43bd7



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

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: Zheng Zengkai <zhengzengkai@huawei.com>