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| author | Eric Dumazet <edumazet@google.com> | 2017-03-21 19:22:28 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2017-06-20 14:04:35 +0200 |
| commit | 7dbfa253c3832f4107ce019d026c7892b7d7ec1a (patch) | |
| tree | f0728d38f96a62f0a54269182252f99112dc7617 /net | |
| parent | 6e37a689238c8bbb5e1de45588a00aa716967089 (diff) | |
| download | linux-7dbfa253c3832f4107ce019d026c7892b7d7ec1a.tar.gz linux-7dbfa253c3832f4107ce019d026c7892b7d7ec1a.tar.bz2 linux-7dbfa253c3832f4107ce019d026c7892b7d7ec1a.zip | |
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: Willy Tarreau <w@1wt.eu>
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 4556cd25acde..017b4792cd44 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -957,7 +957,8 @@ 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; |