diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2022-10-27 14:25:53 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-10-31 09:13:10 +0000 |
| commit | 738136a0e3757a8534df3ad97d6ff6d7f429f6c1 (patch) | |
| tree | 4ea24529d3600c1aa926aaa791f1085af6c111e6 /net/netlink | |
| parent | eca485d22165695587bed02d8b9d0f7f44246c4a (diff) | |
netlink: split up copies in the ack construction
Clean up the use of unsafe_memcpy() by adding a flexible array
at the end of netlink message header and splitting up the header
and data copies.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
| -rw-r--r-- | net/netlink/af_netlink.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index f0c94d394ab1..b10d5e50b99d 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2499,19 +2499,24 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, flags |= NLM_F_ACK_TLVS; skb = nlmsg_new(payload + tlvlen, GFP_KERNEL); - if (!skb) { - NETLINK_CB(in_skb).sk->sk_err = ENOBUFS; - sk_error_report(NETLINK_CB(in_skb).sk); - return; - } + if (!skb) + goto err_bad_put; rep = nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, - NLMSG_ERROR, payload, flags); + NLMSG_ERROR, sizeof(*errmsg), flags); + if (!rep) + goto err_bad_put; errmsg = nlmsg_data(rep); errmsg->error = err; - unsafe_memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) - ? nlh->nlmsg_len : sizeof(*nlh), - /* Bounds checked by the skb layer. */); + errmsg->msg = *nlh; + + if (!(flags & NLM_F_CAPPED)) { + if (!nlmsg_append(skb, nlmsg_len(nlh))) + goto err_bad_put; + + memcpy(errmsg->msg.nlmsg_data, nlh->nlmsg_data, + nlmsg_len(nlh)); + } if (tlvlen) netlink_ack_tlv_fill(in_skb, skb, nlh, err, extack); @@ -2519,6 +2524,12 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, nlmsg_end(skb, rep); nlmsg_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid); + + return; + +err_bad_put: + NETLINK_CB(in_skb).sk->sk_err = ENOBUFS; + sk_error_report(NETLINK_CB(in_skb).sk); } EXPORT_SYMBOL(netlink_ack); |