Re: [PATCH 1/1] NFC: Fix possible memory corruption when handling SHDLC I-Frame commands

On Mon, Aug 13, 2018 at 03:39:08PM -0700, Suren Baghdasaryan wrote:

When handling SHDLC I-Frame commands "pipe" field used for indexing
into an array should be checked before usage. If left unchecked it
might access memory outside of the array of size NFC_HCI_MAX_PIPES(127).

Malformed NFC HCI frames could be injected by a malicious NFC device
communicating with the device being attacked (remote attack vector),
or even by an attacker with physical access to the I2C bus such that
they could influence the data transfers on that bus (local attack vector).
skb->data is controlled by the attacker and has only been sanitized in
the most trivial ways (CRC check), therefore we can consider the
create_info struct and all of its members to tainted. 'create_info->pipe'
with max value of 255 (uint8) is used to take an offset of the
hdev->pipes array of 127 elements which can lead to OOB write.

Suggested-by: Kevin Deus <redacted>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>