diff mbox series

[1/3] mt76: fix frag length allocation for usb

Message ID e4e93439ffa75a94ae7f945100363e3417f76116.1538563675.git.lorenzo.bianconi@redhat.com (mailing list archive)
State Accepted
Delegated to: Kalle Valo
Headers show
Series fix mt76x0u driver hw stop sequence | expand

Commit Message

Lorenzo Bianconi Oct. 3, 2018, 10:52 a.m. UTC 
From: Stanislaw Gruszka <sgruszka@redhat.com>

This is correct fix for c12128ce44b0 ("mt76: use a per rx queue page
fragment cache"). We use wrong length when we allocate segments for
MCU transmissions, which require bigger segment size than e->buf_size.

Commit 481bb0432414 ("mt76: usb: make rx page_frag_cache access atomic")
partially solved the problem or actually mask it by changing
mt76u_mcu_init_rx() and mt76u_alloc_queues() sequence, so e->buf_size
become non zero any longer, but still not big enough to handle MCU data.

Patch fixes memory corruption which can manifest itself as random,
not easy to reproduce crashes, during mt76 driver load or unload.

Fixes: c12128ce44b0 ("mt76: use a per rx queue page fragment cache")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 drivers/net/wireless/mediatek/mt76/usb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
index de7785c4f6af..6b643ea701e3 100644
--- a/drivers/net/wireless/mediatek/mt76/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/usb.c
@@ -286,7 +286,7 @@  mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76u_buf *buf,
 		void *data;
 		int offset;
 
-		data = page_frag_alloc(&q->rx_page, q->buf_size, GFP_ATOMIC);
+		data = page_frag_alloc(&q->rx_page, len, GFP_ATOMIC);
 		if (!data)
 			break;