diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-03-22 05:22:28 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-30 10:35:14 +0300 |
| commit | 38dece41e5be77478b333db580b5e171b136befa (patch) | |
| tree | 508150cf5f1150e72e94f6707504b96a1d997e03 | |
| parent | 85f00dac91a1047b57e600df9636c8408f70001f (diff) | |
| download | linux-38dece41e5be77478b333db580b5e171b136befa.tar.xz | |
ipv4: provide stronger user input validation in nl_fib_input()
[ Upstream commit c64c0b3cac4c5b8cb093727d2c19743ea3965c0b ]
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>
| -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 4e60dae86df5..1adba44f8fbc 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1080,7 +1080,8 @@ 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; |