wifi: rsi: validate beacon length before fixed buffer copy

rsi_prepare_beacon() copies the mac80211 beacon frame after
FRAME_DESC_SZ into a management skb whose usable tailroom may be smaller
than MAX_MGMT_PKT_SIZE after alignment.

Validate the beacon length against the actual tailroom before the copy
and skb_put(). Leave ownership of the management skb with the caller on
error, matching the existing rsi_send_beacon() cleanup path.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260705084824.68105-1-pengpeng@iscas.ac.cn
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Pengpeng Hou
2026-07-05 16:48:24 +08:00
committed by Johannes Berg
parent 74ed3669f2
commit 8ecdeb8b8a

View File

@@ -431,6 +431,7 @@ int rsi_prepare_beacon(struct rsi_common *common, struct sk_buff *skb)
struct ieee80211_vif *vif;
struct sk_buff *mac_bcn;
u8 vap_id = 0, i;
unsigned int tailroom;
u16 tim_offset = 0;
for (i = 0; i < RSI_MAX_VIFS; i++) {
@@ -480,6 +481,13 @@ int rsi_prepare_beacon(struct rsi_common *common, struct sk_buff *skb)
if (mac_bcn->data[tim_offset + 2] == 0)
bcn_frm->frame_info |= cpu_to_le16(RSI_DATA_DESC_DTIM_BEACON);
tailroom = skb_tailroom(skb);
if (tailroom < FRAME_DESC_SZ ||
mac_bcn->len > tailroom - FRAME_DESC_SZ) {
dev_kfree_skb(mac_bcn);
return -EMSGSIZE;
}
memcpy(&skb->data[FRAME_DESC_SZ], mac_bcn->data, mac_bcn->len);
skb_put(skb, mac_bcn->len + FRAME_DESC_SZ);