[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <083b7de74780d65dfdd6f448288489464fa2da40.1491838390.git.jslaby@suse.cz>
Date: Mon, 10 Apr 2017 17:32:25 +0200
From: Jiri Slaby <jslaby@...e.cz>
To: stable@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, Eric Dumazet <edumazet@...gle.com>,
"David S . Miller" <davem@...emloft.net>
Subject: [PATCH 3.12 064/142] ipv4: provide stronger user input validation in nl_fib_input()
From: Eric Dumazet <edumazet@...gle.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
[ 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@...gle.com>
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
---
net/ipv4/fib_frontend.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 3d3966bf3df6..4a30de61bec1 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -965,7 +965,8 @@ 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;
--
2.12.2
Powered by blists - more mailing lists