diff options
| author | Stanislav Fort <stanislav.fort@aisle.com> | 2025-08-31 16:56:23 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-09 19:02:34 +0200 |
| commit | a67c6397fcb7e842d3c595243049940970541c48 (patch) | |
| tree | 4377eb836541133048a286293a9f7b74b9a022c5 | |
| parent | 9735a9dcc307427e7d6336c54171682f1bac9789 (diff) | |
batman-adv: fix OOB read/write in network-coding decode
commit d77b6ff0ce35a6d0b0b7b9581bc3f76d041d4087 upstream.
batadv_nc_skb_decode_packet() trusts coded_len and checks only against
skb->len. XOR starts at sizeof(struct batadv_unicast_packet), reducing
payload headroom, and the source skb length is not verified, allowing an
out-of-bounds read and a small out-of-bounds write.
Validate that coded_len fits within the payload area of both destination
and source sk_buffs before XORing.
Fixes: 2df5278b0267 ("batman-adv: network coding - receive coded packets and decode them")
Cc: stable@vger.kernel.org
Reported-by: Stanislav Fort <disclosure@aisle.com>
Signed-off-by: Stanislav Fort <stanislav.fort@aisle.com>
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>
| -rw-r--r-- | net/batman-adv/network-coding.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index 9f56308779cc..af97d077369f 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -1687,7 +1687,12 @@ batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, coding_len = ntohs(coded_packet_tmp.coded_len); - if (coding_len > skb->len) + /* ensure dst buffer is large enough (payload only) */ + if (coding_len + h_size > skb->len) + return NULL; + + /* ensure src buffer is large enough (payload only) */ + if (coding_len + h_size > nc_packet->skb->len) return NULL; /* Here the magic is reversed: |