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authorStanislav Fort <[email protected]>2025-08-31 14:56:23 +0000
committerSimon Wunderlich <[email protected]>2025-08-31 15:01:35 +0000
commitd77b6ff0ce35a6d0b0b7b9581bc3f76d041d4087 (patch)
tree4870a24b7ab279ae6b356dc2f67a46052f9c638e
parentMerge tag 'net-6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/net... (diff)
downloadkernel-d77b6ff0ce35a6d0b0b7b9581bc3f76d041d4087.tar.gz
kernel-d77b6ff0ce35a6d0b0b7b9581bc3f76d041d4087.zip
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]>
-rw-r--r--net/batman-adv/network-coding.c7
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: