diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-03-21 19:22:28 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-22 07:15:03 +0200 |
| commit | 102f190c4b1edbb3a377c2e90074a3b09529c6b3 (patch) | |
| tree | 653158a468207c958d24760e7605e968c393f6ff /net | |
| parent | 3f01e667e6f5efcd7e89adc3aaf0d74492786fb8 (diff) | |
ipv4: provide stronger user input validation in nl_fib_input()
commit c64c0b3cac4c5b8cb093727d2c19743ea3965c0b upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to '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 d4c698ce0838..1c77a94c0cbf 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -961,7 +961,8 @@ 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; |