oss-security - CVE Request: Linux kernel: Buffer overflow when copying data from skbuff to userspace

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date: Tue, 27 Oct 2015 14:16:44 +0100
From: Sabrina Dubroca <sd@...asysnail.net>
To: oss-security@...ts.openwall.com
Cc: hannes@...essinduktion.org
Subject: CVE Request: Linux kernel: Buffer overflow when copying data from
 skbuff to userspace

skb_copy_and_csum_datagram_iovec doesn't check the actual length of
the iovec's buffers to which it copies data, then memcpy_toiovec can
copy to an address that was not specified by userspace, but garbage
lying on the kernel stack.

In some cases, this address can be a valid userspace address, to which
memcpy_toiovec will write the buffers.
This can happen when userspace calls write followed by recvmsg.

In that case, memcpy_toiovec will dump the packet contents to the
buffer passed to the write call, and can for example overwrite stack
contents.

Patch has been submitted:
http://patchwork.ozlabs.org/patch/530642/

Versions affected:
stable kernels before v3.19 (3.x.y, x <= 18) that have backported
commit 89c22d8c3b27 ("net: Fix skb csum races when peeking")

v3.18.22
v3.14.54+
v3.12.48, v3.12.49
v3.10.90+
v3.2.72
3.16.7-ckt17, 3.16.7-ckt18
3.13.11-ckt27, 3.13.11-ckt28

Could we get a CVE for this?

Thanks,

-- 
Sabrina

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.