[PATCH] mt76: mt7921s: fix possible kernel crash due to invalid Rx count

[sean.wang at mediatek.com]

From: Sean Wang <sean.wang at mediatek.com>

Return the proper error code when out-of-range the Rx aggregation count
are reported from the hardware that would create the unreasonable extreme
large Rx buffer.

[  100.873810]  show_stack+0x20/0x2c
[  100.873823]  dump_stack+0xc4/0x140
[  100.873839]  bad_page+0x110/0x114
[  100.873854]  check_new_pages+0xf8/0xfc
[  100.873869]  rmqueue+0x5a0/0x640
[  100.873884]  get_page_from_freelist+0x124/0x20c
[  100.873898]  __alloc_pages_nodemask+0x114/0x2a4
[  100.873918]  mt76s_rx_run_queue+0xd4/0x2e4 [mt76_sdio 8280a88a0c8c9cf203f16e194f99ac293bdbb2f5]
[  100.873938]  mt76s_rx_handler+0xd4/0x2a0 [mt76_sdio 8280a88a0c8c9cf203f16e194f99ac293bdbb2f5]
[  100.873957]  mt76s_txrx_worker+0xac/0x17c [mt76_sdio 8280a88a0c8c9cf203f16e194f99ac293bdbb2f5]
[  100.873977]  mt7921s_txrx_worker+0x5c/0xd8 [mt7921s d0bdbc018082dbc8dc1407614be3c2e7bd64423b]
[  100.874003]  __mt76_worker_fn+0xe8/0x170 [mt76 b80af3483a8f9d48e916c12d8dbfaa0d3cd15337]
[  100.874018]  kthread+0x148/0x3ac
[  100.874032]  ret_from_fork+0x10/0x30
[  100.874067] Kernel Offset: 0x1fe2000000 from 0xffffffc010000000
[  100.874079] PHYS_OFFSET: 0xffffffe800000000
[  100.874090] CPU features: 0x0240002,2188200c

Fixes: 48fab5bbef40 ("mt76: mt7921: introduce mt7921s support")
Signed-off-by: Sean Wang <sean.wang at mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7921/sdio.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
index 5c88b6b8d097..84be229a899d 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c
@@ -62,6 +62,10 @@ static int mt7921s_parse_intr(struct mt76_dev *dev, struct mt76s_intr *intr)
 	if (err < 0)
 		return err;
 
+	if (irq_data->rx.num[0] > 16 ||
+	    irq_data->rx.num[1] > 128)
+		return -EINVAL;
+
 	intr->isr = irq_data->isr;
 	intr->rec_mb = irq_data->rec_mb;
 	intr->tx.wtqcr = irq_data->tx.wtqcr;
-- 
2.25.1