diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-03-21 19:22:28 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-03-22 14:15:49 -0700 |
| commit | c64c0b3cac4c5b8cb093727d2c19743ea3965c0b (patch) | |
| tree | cf028128aa74adefd46b05428bcc82cb132c9f43 | |
| parent | 8c290e60fa2a51806159522331c9ed41252a8fb3 (diff) | |
ipv4: provide stronger user input validation in nl_fib_input()
Alexander reported a KMSAN splat caused by reads of uninitialized
field (tb_id_in) from user provided struct fib_result_nl
It turns out nl_fib_input() sanity tests on user input is a bit
wrong :
User can pretend nlh->nlmsg_len is big enough, but provide
at sendmsg() time a too small buffer.
Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/fib_frontend.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 42bfd08109dd..8f2133ffc2ff 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1083,7 +1083,8 @@ static void nl_fib_input(struct sk_buff *skb) net = sock_net(skb->sk); nlh = nlmsg_hdr(skb); - if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len || + if (skb->len < nlmsg_total_size(sizeof(*frn)) || + skb->len < nlh->nlmsg_len || nlmsg_len(nlh) < sizeof(*frn)) return; |