Vegard Nossum e6522330b7 batman-adv: Don't accept TT entries for out-of-spec VIDs
commit 537a350d14321c8cca5efbf0a33a404fec3a9f9e upstream.

The internal handling of VLAN IDs in batman-adv is only specified for
following encodings:

* VLAN is used
  - bit 15 is 1
  - bit 11 - bit 0 is the VLAN ID (0-4095)
  - remaining bits are 0
* No VLAN is used
  - bit 15 is 0
  - remaining bits are 0

batman-adv was only preparing new translation table entries (based on its
soft interface information) using this encoding format. But the receive
path was never checking if entries in the roam or TT TVLVs were also
following this encoding.

It was therefore possible to create more than the expected maximum of 4096
+ 1 entries in the originator VLAN list. Simply by setting the "remaining
bits" to "random" values in corresponding TVLV.

Cc: stable@vger.kernel.org
Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
Reported-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 4d5a2d6b7a9a1140342c5229d1a427ec37a12fd4)
[Vegard: fix trivial conflicts due to missing commit 7e9a8c2ce7c5
 ("batman-adv: Use parentheses in function kernel-doc").]
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
2024-08-08 15:52:21 +00:00
..