From: Haimin Zhang tcs_kernel@tencent.com
[ Upstream commit 9a564bccb78a76740ea9d75a259942df8143d02c ]
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 --- net/key/af_key.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/key/af_key.c b/net/key/af_key.c index 406e13478b01..2ac9560020f9 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -1703,7 +1703,7 @@ static int pfkey_register(struct sock *sk, struct sk_buff *skb, const struct sad
xfrm_probe_algs();
- supp_skb = compose_sadb_supported(hdr, GFP_KERNEL); + supp_skb = compose_sadb_supported(hdr, GFP_KERNEL | __GFP_ZERO); if (!supp_skb) { if (hdr->sadb_msg_satype != SADB_SATYPE_UNSPEC) pfk->registered &= ~(1<<hdr->sadb_msg_satype);