From: Pengpeng Hou Date: Sun, 5 Jul 2026 08:48:24 +0000 (+0800) Subject: wifi: rsi: validate beacon length before fixed buffer copy X-Git-Tag: v7.2-rc4~17^2~16^2~22 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8ecdeb8b8a33b22c597299043c0dcfce50beb9ea;p=thirdparty%2Fkernel%2Flinux.git 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 Link: https://patch.msgid.link/20260705084824.68105-1-pengpeng@iscas.ac.cn Signed-off-by: Johannes Berg --- diff --git a/drivers/net/wireless/rsi/rsi_91x_hal.c b/drivers/net/wireless/rsi/rsi_91x_hal.c index a0c36144eb0b..501071104a9f 100644 --- a/drivers/net/wireless/rsi/rsi_91x_hal.c +++ b/drivers/net/wireless/rsi/rsi_91x_hal.c @@ -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);