From 9a564bccb78a76740ea9d75a259942df8143d02c Mon Sep 17 00:00:00 2001 From: Haimin Zhang Date: Tue, 8 Mar 2022 11:20:28 +0800 Subject: af_key: add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register 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 Signed-off-by: Haimin Zhang Signed-off-by: Steffen Klassert --- 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 9bf52a09b5ff..fd51db3be91c 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -1699,7 +1699,7 @@ 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<sadb_msg_satype); -- cgit From 4db4075f92af2b28f415fc979ab626e6b37d67b6 Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Thu, 10 Mar 2022 11:49:00 +0100 Subject: esp6: fix check on ipv6_skip_exthdr's return value Commit 5f9c55c8066b ("ipv6: check return value of ipv6_skip_exthdr") introduced an incorrect check, which leads to all ESP packets over either TCPv6 or UDPv6 encapsulation being dropped. In this particular case, offset is negative, since skb->data points to the ESP header in the following chain of headers, while skb->network_header points to the IPv6 header: IPv6 | ext | ... | ext | UDP | ESP | ... That doesn't seem to be a problem, especially considering that if we reach esp6_input_done2, we're guaranteed to have a full set of headers available (otherwise the packet would have been dropped earlier in the stack). However, it means that the return value will (intentionally) be negative. We can make the test more specific, as the expected return value of ipv6_skip_exthdr will be the (negated) size of either a UDP header, or a TCP header with possible options. In the future, we should probably either make ipv6_skip_exthdr explicitly accept negative offsets (and adjust its return value for error cases), or make ipv6_skip_exthdr only take non-negative offsets (and audit all callers). Fixes: 5f9c55c8066b ("ipv6: check return value of ipv6_skip_exthdr") Reported-by: Xiumei Mu Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert --- net/ipv6/esp6.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index b0ffbcd5432d..55d604c9b3b3 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -812,8 +812,7 @@ int esp6_input_done2(struct sk_buff *skb, int err) struct tcphdr *th; offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); - - if (offset < 0) { + if (offset == -1) { err = -EINVAL; goto out; } -- cgit