Fwd: Re: cve request: bat_socket_read memory corruption

[Kurt Seifried <kseifried () redhat com>]

Please USE CVE-2011-4604 for this issue.

-------- Original Message --------
Subject:        Re: [oss-security] cve request: bat_socket_read memory corruption
Date:   Sat, 10 Dec 2011 20:35:33 +0100
From:   Paul <pawlkt () gmail com>
To:     kseifried () redhat com



On 2011-12-10 20:30, Kurt Seifried wrote:
> On 12/10/2011 09:13 AM, Paul wrote:
> > Hi
> >
> > can I get a CVE for this:
> > https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2011-December/005904.html
> > ?
> >
> > If root does read() on a specific socket, it's possible to corrupt
> > (kernel) memory over network, with an ICMP packet, if B.A.T.M.A.N. mesh
> > protocol is used.
> I'm going to need first hand source information, i.e. links to the
> code/commits/project stating it's an issue or something similar.

https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2011-December/005908.html

Modified patch from Sven Eckelmann, one of project's managers.

-- 
Regards,
Paul


===========================

Don't write more than the requested number of bytes of an batman-adv icmp
packet to the userspace buffer. Otherwise unrelated userspace memory might get
overwritten by the kernel.

Reported-by: Paul Kot <pawlkt at gmail.com <https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n>>
Signed-off-by: Sven Eckelmann <sven at narfation.org <https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n>>
---
Marek pointed out that it is better to merge patch 1 and 2. I think it doesn't
make sense to leave Paul Kot as author because it doesn't look like his patch
at all.

And thanks to Andrew for s/overridden/overwritten/

 icmp_socket.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/icmp_socket.c b/icmp_socket.c
index 5bc8649..66923d2 100644
--- a/icmp_socket.c
+++ b/icmp_socket.c
@@ -136,10 +136,9 @@ static ssize_t bat_socket_read(struct file *file, char __user *buf,
 
        spin_unlock_bh(&socket_client->lock);
 
-       error = __copy_to_user(buf, &socket_packet->icmp_packet,
-                              socket_packet->icmp_len);
+       packet_len = min(count, socket_packet->icmp_len);
+       error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
 
-       packet_len = socket_packet->icmp_len;
        kfree(socket_packet);
 
        if (error)
-- 
1.7.7.3