af_key: add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register

stable inclusion
from stable-v4.19.238
commit 693fe8af9a2625139de07bd1ae212a7d89c37795
category: bugfix
bugzilla: 186606, https://gitee.com/src-openeuler/kernel/issues/I53SSV


CVE: CVE-2022-1353

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

[ Upstream commit 9a564bcc ]

Add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register
to initialize the buffer of supp_skb to fix a kernel-info-leak issue.
1) Function pfkey_register calls compose_sadb_supported to request
a sk_buff. 2) compose_sadb_supported calls alloc_sbk to allocate
a sk_buff, but it doesn't zero it. 3) If auth_len is greater 0, then
compose_sadb_supported treats the memory as a struct sadb_supported and
begins to initialize. But it just initializes the field sadb_supported_len
and field sadb_supported_exttype without field sadb_supported_reserved.

Reported-by: TCS Robot <tcs_robot@tencent.com>
Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Xu Jia <xujia39@huawei.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>