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From: Sascha Hauer <s.hauer@pengutronix.de>
To: Barebox List <barebox@lists.infradead.org>
Cc: jianqiang wang <wjq.sec@gmail.com>
Subject: [PATCH v3 3/9] net: ks8851_mll: do not read past the receive buffer
Date: Tue, 28 May 2024 10:58:00 +0200	[thread overview]
Message-ID: <20240528085806.1172689-4-s.hauer@pengutronix.de> (raw)
In-Reply-To: <20240528085806.1172689-1-s.hauer@pengutronix.de>

the hardware may report a packet longer than our receive buffer. Instead
of reading past the receive buffer, discard too long packets.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/net/ks8851_mll.c | 36 ++++++++++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ks8851_mll.c b/drivers/net/ks8851_mll.c
index 2120657bd9..936191597a 100644
--- a/drivers/net/ks8851_mll.c
+++ b/drivers/net/ks8851_mll.c
@@ -420,6 +420,23 @@ static inline void ks_inblk(struct ks_net *ks, u16 *wptr, u32 len)
 		*wptr++ = (u16)readw(ks->hw_addr);
 }
 
+/**
+ * ks_discardblk - read a block of data from QMU discarding the data
+ * @ks: The chip state
+ * @len: length in byte to read
+ *
+ * This discards a block of data, used when a packet is longer than our receive
+ * buffer. I don't know if it is necessary to discard the data like this, but
+ * it is the easy way out to fix the behaviour with too large packets without
+ * risking regressions.
+ */
+static inline void ks_discardblk(struct ks_net *ks, u32 len)
+{
+	len >>= 1;
+	while (len--)
+		(void)readw(ks->hw_addr);
+}
+
 /**
  * ks_outblk - write data to QMU.
  * @ks: The chip information
@@ -676,16 +693,23 @@ static int ks8851_rx_frame(struct ks_net *ks)
 
 	tmp_rxqcr = ks_rdreg16(ks, KS_RXQCR);
 	ks_wrreg16(ks, KS_RXQCR, tmp_rxqcr | RXQCR_SDA);
-	/* read 2 bytes for dummy, 2 for status, 2 for len*/
-	ks_inblk(ks, ks->rx_buf, 2 + 2 + 2);
-	ks_inblk(ks, ks->rx_buf, ALIGN(RxLen, 4));
+	if (RxLen <= PKTSIZE) {
+		/* read 2 bytes for dummy, 2 for status, 2 for len*/
+		ks_inblk(ks, ks->rx_buf, 2 + 2 + 2);
+		ks_inblk(ks, ks->rx_buf, ALIGN(RxLen, 4));
+	} else {
+		ks_discardblk(ks, 2 + 2 + 2 + ALIGN(RxLen, 4));
+	}
+
 	ks_wrreg16(ks, KS_RXQCR, tmp_rxqcr);
 
 	if (RxStatus & RXFSHR_RXFV) {
 		/* Pass to upper layer */
-		dev_dbg(dev, "passing packet to upper layer\n\n");
-		net_receive(&ks->edev, ks->rx_buf, RxLen);
-		return RxLen;
+		if (RxLen <= PKTSIZE) {
+			dev_dbg(dev, "passing packet to upper layer\n\n");
+			net_receive(&ks->edev, ks->rx_buf, RxLen);
+		}
+		return;
 	} else if (RxStatus & RXFSHR_ERR) {
 		dev_err(dev, "RxStatus error 0x%04x\n", RxStatus & RXFSHR_ERR);
 		if (RxStatus & RXFSHR_RXICMPFCS)
-- 
2.39.2




  parent reply	other threads:[~2024-05-28  8:58 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-28  8:57 [PATCH v3 0/9] net: do not read past " Sascha Hauer
2024-05-28  8:57 ` [PATCH v3 1/9] net: cs8900: simplify buffer read loop Sascha Hauer
2024-05-28  8:57 ` [PATCH v3 2/9] net: cs8900: do not read past the receive buffer Sascha Hauer
2024-05-28  8:58 ` Sascha Hauer [this message]
2024-05-28  8:58 ` [PATCH v3 4/9] net: liteeth: " Sascha Hauer
2024-05-28  8:58 ` [PATCH v3 5/9] net: liteeth: do not set len to 0 before printing it Sascha Hauer
2024-05-28  8:58 ` [PATCH v3 6/9] net: smc911x: Fix amount of words read from RX FIFO Sascha Hauer
2024-05-28  8:58 ` [PATCH v3 7/9] net: smc911x: do not read past the receive buffer Sascha Hauer
2024-05-28 13:29   ` Jules Maselbas
2024-05-28 14:23     ` [PATCH] fixup! " Sascha Hauer
2024-05-28 14:26     ` [PATCH v3 7/9] " Sascha Hauer
2024-05-28 14:37       ` Jules Maselbas
2024-05-28  8:58 ` [PATCH v3 8/9] net: ks8851_mll: drop return value from ks8851_rx_frame() Sascha Hauer
2024-05-28  8:58 ` [PATCH v3 9/9] net: let net rx hook return void Sascha Hauer

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