758290defe
commit 57bc3d3ae8c14df3ceb4e17d26ddf9eeab304581 upstream.
ax88179_rx_fixup() contains several out-of-bounds accesses that can be
triggered by a malicious (or defective) USB device, in particular:
- The metadata array (hdr_off..hdr_off+2*pkt_cnt) can be out of bounds,
causing OOB reads and (on big-endian systems) OOB endianness flips.
- A packet can overlap the metadata array, causing a later OOB
endianness flip to corrupt data used by a cloned SKB that has already
been handed off into the network stack.
- A packet SKB can be constructed whose tail is far beyond its end,
causing out-of-bounds heap data to be considered part of the SKB's
data.
I have tested that this can be used by a malicious USB device to send a
bogus ICMPv6 Echo Request and receive an ICMPv6 Echo Reply in response
that contains random kernel heap data.
It's probably also possible to get OOB writes from this on a
little-endian system somehow - maybe by triggering skb_cow() via IP
options processing -, but I haven't tested that.
Fixes: e2ca90c276 ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to gigabit ethernet adapter driver")
Cc: stable@kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.