The following commit has been merged in the master branch:
commit d77b6ff0ce35a6d0b0b7b9581bc3f76d041d4087
Author: Stanislav Fort <[email protected]>
Date: Sun Aug 31 16:56:23 2025 +0200
batman-adv: fix OOB read/write in network-coding decode
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: [email protected]
Reported-by: Stanislav Fort <[email protected]>
Signed-off-by: Stanislav Fort <[email protected]>
Signed-off-by: Sven Eckelmann <[email protected]>
Signed-off-by: Simon Wunderlich <[email protected]>
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 9f56308779cc3..af97d077369f9 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:
--
LinuxNextTracking
