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[3.11.y.z,extended,stable] Patch "net: inet_diag: zero out uninitialized idiag_{src, dst} fields" has been added to staging queue

Message ID 1389624234-24081-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Jan. 13, 2014, 2:43 p.m. UTC
This is a note to let you know that I have just added a patch titled

    net: inet_diag: zero out uninitialized idiag_{src,dst} fields

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From e5e81e0b5cbbe627b252d5f8930e86e8adf38202 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <dborkman@redhat.com>
Date: Tue, 17 Dec 2013 00:38:39 +0100
Subject: net: inet_diag: zero out uninitialized idiag_{src,dst} fields

commit b1aac815c0891fe4a55a6b0b715910142227700f upstream.

Jakub reported while working with nlmon netlink sniffer that parts of
the inet_diag_sockid are not initialized when r->idiag_family != AF_INET6.
That is, fields of r->id.idiag_src[1 ... 3], r->id.idiag_dst[1 ... 3].

In fact, it seems that we can leak 6 * sizeof(u32) byte of kernel [slab]
memory through this. At least, in udp_dump_one(), we allocate a skb in ...

  rep = nlmsg_new(sizeof(struct inet_diag_msg) + ..., GFP_KERNEL);

... and then pass that to inet_sk_diag_fill() that puts the whole struct
inet_diag_msg into the skb, where we only fill out r->id.idiag_src[0],
r->id.idiag_dst[0] and leave the rest untouched:

  r->id.idiag_src[0] = inet->inet_rcv_saddr;
  r->id.idiag_dst[0] = inet->inet_daddr;

struct inet_diag_msg embeds struct inet_diag_sockid that is correctly /
fully filled out in IPv6 case, but for IPv4 not.

So just zero them out by using plain memset (for this little amount of
bytes it's probably not worth the extra check for idiag_family == AF_INET).

Similarly, fix also other places where we fill that out.

Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ luis: backported to 3.11: used davem's backport to 3.10 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 net/ipv4/inet_diag.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

--
1.8.3.2
diff mbox

Patch

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 5f64875..31cf54d 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -106,6 +106,10 @@  int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,

 	r->id.idiag_sport = inet->inet_sport;
 	r->id.idiag_dport = inet->inet_dport;
+
+	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
+	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
+
 	r->id.idiag_src[0] = inet->inet_rcv_saddr;
 	r->id.idiag_dst[0] = inet->inet_daddr;

@@ -240,12 +244,19 @@  static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,

 	r->idiag_family	      = tw->tw_family;
 	r->idiag_retrans      = 0;
+
 	r->id.idiag_if	      = tw->tw_bound_dev_if;
 	sock_diag_save_cookie(tw, r->id.idiag_cookie);
+
 	r->id.idiag_sport     = tw->tw_sport;
 	r->id.idiag_dport     = tw->tw_dport;
+
+	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
+	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
+
 	r->id.idiag_src[0]    = tw->tw_rcv_saddr;
 	r->id.idiag_dst[0]    = tw->tw_daddr;
+
 	r->idiag_state	      = tw->tw_substate;
 	r->idiag_timer	      = 3;
 	r->idiag_expires      = DIV_ROUND_UP(tmo * 1000, HZ);
@@ -732,8 +743,13 @@  static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,

 	r->id.idiag_sport = inet->inet_sport;
 	r->id.idiag_dport = ireq->rmt_port;
+
+	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
+	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
+
 	r->id.idiag_src[0] = ireq->loc_addr;
 	r->id.idiag_dst[0] = ireq->rmt_addr;
+
 	r->idiag_expires = jiffies_to_msecs(tmo);
 	r->idiag_rqueue = 0;
 	r->idiag_wqueue = 0;