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| author |   Kees Cook <keescook@chromium.org> | 2022-09-02 21:37:49 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2022-09-05 14:45:22 +0100 |
| commit | 710d21fdff9a98d621cd4e64167f3ef8af4e2fd1 (patch) | |
| tree | c039cd1cbfc4dc5dc57138e1d5752e155810be5a /net/netfilter/ipset/ip_set_core.c | |
| parent | net: phy: Add 1000BASE-KX interface mode (diff) | |
| download | wireguard-linux-710d21fdff9a98d621cd4e64167f3ef8af4e2fd1.tar.xz wireguard-linux-710d21fdff9a98d621cd4e64167f3ef8af4e2fd1.zip | |
netlink: Bounds-check struct nlmsgerr creation
In preparation for FORTIFY_SOURCE doing bounds-check on memcpy(),
switch from __nlmsg_put to nlmsg_put(), and explain the bounds check
for dealing with the memcpy() across a composite flexible array struct.
Avoids this future run-time warning:
memcpy: detected field-spanning write (size 32) of single field "&errmsg->msg" at net/netlink/af_netlink.c:2447 (size 16)
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: syzbot <syzkaller@googlegroups.com>
Cc: netfilter-devel@vger.kernel.org
Cc: coreteam@netfilter.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220901071336.1418572-1-keescook@chromium.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netfilter/ipset/ip_set_core.c')
| -rw-r--r-- | net/netfilter/ipset/ip_set_core.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index 16ae92054baa..6b31746f9be3 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1719,11 +1719,13 @@ call_ad(struct net *net, struct sock *ctnl, struct sk_buff *skb, skb2 = nlmsg_new(payload, GFP_KERNEL); if (!skb2) return -ENOMEM; - rep = __nlmsg_put(skb2, NETLINK_CB(skb).portid, - nlh->nlmsg_seq, NLMSG_ERROR, payload, 0); + rep = nlmsg_put(skb2, NETLINK_CB(skb).portid, + nlh->nlmsg_seq, NLMSG_ERROR, payload, 0); errmsg = nlmsg_data(rep); errmsg->error = ret; - memcpy(&errmsg->msg, nlh, nlh->nlmsg_len); + unsafe_memcpy(&errmsg->msg, nlh, nlh->nlmsg_len, + /* Bounds checked by the skb layer. */); + cmdattr = (void *)&errmsg->msg + min_len; ret = nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr, |