6620d5e5d1
commit 8ba0f9bd3bdea1058c2b2676bec7905724418e40 upstream.
The functions batadv_tt_prepare_tvlv_local_data and
batadv_tt_prepare_tvlv_global_data are responsible for preparing a buffer
which can be used to store the TVLV container for TT and add the VLAN
information to it.
This will be done in three phases:
1. count the number of VLANs and their entries
2. allocate the buffer using the counters from the previous step and limits
from the caller (parameter tt_len)
3. insert the VLAN information to the buffer
The step 1 and 3 operate on a list which contains the VLANs. The access to
these lists must be protected with an appropriate lock or otherwise they
might operate on on different entries. This could for example happen when
another context is adding VLAN entries to this list.
This could lead to a buffer overflow in these functions when enough entries
were added between step 1 and 3 to the VLAN lists that the buffer room for
the entries (*tt_change) is smaller then the now required extra buffer for
new VLAN entries.
Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.