[PATCH AUTOSEL 6.18] wifi: wl1251: validate packet IDs before indexing tx_frames

[Sasha Levin]

From: Pengpeng Hou <pengpeng@xxxxxxxxxxx>

[ Upstream commit 0fd56fad9c56356e7fa7a7c52e7ecbf807a44eb0 ]

wl1251_tx_packet_cb() uses the firmware completion ID directly to index
the fixed 16-entry wl->tx_frames[] array. The ID is a raw u8 from the
completion block, and the callback does not currently verify that it
fits the array before dereferencing it.

Reject completion IDs that fall outside wl->tx_frames[] and keep the
existing NULL check in the same guard. This keeps the fix local to the
trust boundary and avoids touching the rest of the completion flow.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
Link: https://patch.msgid.link/20260323080845.40033-1-pengpeng@xxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---

LLM Generated explanations, may be completely bogus:

Error: Failed to generate final synthesis

 drivers/net/wireless/ti/wl1251/tx.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ti/wl1251/tx.c b/drivers/net/wireless/ti/wl1251/tx.c
index adb4840b04893..c264d83e71d9c 100644
--- a/drivers/net/wireless/ti/wl1251/tx.c
+++ b/drivers/net/wireless/ti/wl1251/tx.c
@@ -402,12 +402,14 @@ static void wl1251_tx_packet_cb(struct wl1251 *wl,
 	int hdrlen;
 	u8 *frame;
 
-	skb = wl->tx_frames[result->id];
-	if (skb == NULL) {
-		wl1251_error("SKB for packet %d is NULL", result->id);
+	if (unlikely(result->id >= ARRAY_SIZE(wl->tx_frames) ||
+		     wl->tx_frames[result->id] == NULL)) {
+		wl1251_error("invalid packet id %u", result->id);
 		return;
 	}
 
+	skb = wl->tx_frames[result->id];
+
 	info = IEEE80211_SKB_CB(skb);
 
 	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
-- 
2.53.0