Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com

Tested on:

commit:         33d9269e Revert "kernel: kmsan: don't instrument stack..
git tree:       https://github.com/google/kmsan.git master
kernel config:  https://syzkaller.appspot.com/x/.config?x=d830111cc3be873
dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
compiler:       clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1130ceb7700000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[David Kahurani]

[-- Attachment #1: Type: text/plain, Size: 1007 bytes --]

Made some changes, got to test this again just to be sure.

#syz test https://github.com/google/kmsan.git master

On Sat, Apr 9, 2022 at 11:40 AM syzbot
<syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot has tested the proposed patch and the reproducer did not trigger any issue:
>
> Reported-and-tested-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com
>
> Tested on:
>
> commit:         33d9269e Revert "kernel: kmsan: don't instrument stack..
> git tree:       https://github.com/google/kmsan.git master
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d830111cc3be873
> dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
> compiler:       clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
> patch:          https://syzkaller.appspot.com/x/patch.diff?x=1130ceb7700000
>
> Note: testing is done by a robot and is best-effort only.

[-- Attachment #2: 0001-net-ax88179-add-proper-error-handling-of-usb-read-er.patch --]
[-- Type: text/x-patch, Size: 17762 bytes --]

From 52430ebdbce0192019e1b354fb5cba487ebcfb09 Mon Sep 17 00:00:00 2001
From: David Kahurani <k.kahurani@gmail.com>
Date: Thu, 14 Apr 2022 15:16:02 +0300
Subject: [PATCH] net: ax88179: add proper error handling of usb read errors

Reads that are lesser than the requested size lead to uninit-value bugs.
An example of such a bug can be seen below whereby a local variable into
which the contents of reads were supposed to be stored is left
uninitialized after a partial read.

Qualify such reads as errors and handle them correctly.

Local variable eeprom.i created at:
 ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1045 [inline]
 ax88179_led_setting+0x2e2/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_bind+0xf00/0x1a50 drivers/net/usb/ax88179_178a.c:1412

Fixes: e2ca90c276e1 ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to
gigabit ethernet adapter driver")
Signed-off-by: David Kahurani <k.kahurani@gmail.com>
Reported-and-tested-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com
---
 drivers/net/usb/ax88179_178a.c | 279 ++++++++++++++++++++++++++-------
 1 file changed, 226 insertions(+), 53 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index e2fa56b92..5113ed63f 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -185,8 +185,9 @@ static const struct {
 	{7, 0xcc, 0x4c, 0x18, 8},
 };
 
-static int __ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
-			      u16 size, void *data, int in_pm)
+static int __must_check __ax88179_read_cmd(struct usbnet *dev, u8 cmd,
+					   u16 value, u16 index, u16 size,
+					   void *data, int in_pm)
 {
 	int ret;
 	int (*fn)(struct usbnet *, u8, u8, u16, u16, void *, u16);
@@ -201,11 +202,15 @@ static int __ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
 	ret = fn(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 		 value, index, data, size);
 
-	if (unlikely(ret < 0))
+	if (unlikely(ret < size)) {
+		ret = ret < 0 ? ret : -ENODATA;
+
 		netdev_warn(dev->net, "Failed to read reg index 0x%04x: %d\n",
 			    index, ret);
+		return ret;
+	}
 
-	return ret;
+	return 0;
 }
 
 static int __ax88179_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
@@ -249,26 +254,33 @@ static void ax88179_write_cmd_async(struct usbnet *dev, u8 cmd, u16 value,
 	}
 }
 
-static int ax88179_read_cmd_nopm(struct usbnet *dev, u8 cmd, u16 value,
-				 u16 index, u16 size, void *data)
+static int __must_check ax88179_read_cmd_nopm(struct usbnet *dev, u8 cmd,
+					      u16 value, u16 index, u16 size,
+					      void *data)
 {
 	int ret;
 
 	if (2 == size) {
 		u16 buf;
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, &buf, 1);
+		if (ret)
+			return ret;
 		le16_to_cpus(&buf);
 		*((u16 *)data) = buf;
 	} else if (4 == size) {
 		u32 buf;
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, &buf, 1);
+		if (ret)
+			return ret;
 		le32_to_cpus(&buf);
 		*((u32 *)data) = buf;
 	} else {
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, data, 1);
+		if (ret)
+			return ret;
 	}
 
-	return ret;
+	return 0;
 }
 
 static int ax88179_write_cmd_nopm(struct usbnet *dev, u8 cmd, u16 value,
@@ -290,26 +302,32 @@ static int ax88179_write_cmd_nopm(struct usbnet *dev, u8 cmd, u16 value,
 	return ret;
 }
 
-static int ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
-			    u16 size, void *data)
+static int __must_check ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value,
+					 u16 index, u16 size, void *data)
 {
 	int ret;
 
 	if (2 == size) {
 		u16 buf = 0;
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, &buf, 0);
+		if (ret)
+			return ret;
 		le16_to_cpus(&buf);
 		*((u16 *)data) = buf;
 	} else if (4 == size) {
 		u32 buf = 0;
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, &buf, 0);
+		if (ret)
+			return ret;
 		le32_to_cpus(&buf);
 		*((u32 *)data) = buf;
 	} else {
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, data, 0);
+		if (ret)
+			return ret;
 	}
 
-	return ret;
+	return 0;
 }
 
 static int ax88179_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
@@ -354,8 +372,15 @@ static int ax88179_mdio_read(struct net_device *netdev, int phy_id, int loc)
 {
 	struct usbnet *dev = netdev_priv(netdev);
 	u16 res;
+	int ret;
+
+	ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, phy_id, (__u16)loc, 2, &res);
+
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read PHY_ID: %d\n", ret);
+		return ret;
+	}
 
-	ax88179_read_cmd(dev, AX_ACCESS_PHY, phy_id, (__u16)loc, 2, &res);
 	return res;
 }
 
@@ -416,7 +441,7 @@ ax88179_phy_write_mmd_indirect(struct usbnet *dev, u16 prtad, u16 devad,
 	ret = ax88179_write_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
 				MII_MMD_DATA, 2, &data);
 
-	if (ret < 0)
+	if (ret)
 		return ret;
 
 	return 0;
@@ -427,19 +452,31 @@ static int ax88179_suspend(struct usb_interface *intf, pm_message_t message)
 	struct usbnet *dev = usb_get_intfdata(intf);
 	u16 tmp16;
 	u8 tmp8;
+	int ret;
 
 	usbnet_suspend(intf, message);
 
 	/* Disable RX path */
-	ax88179_read_cmd_nopm(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
-			      2, 2, &tmp16);
+	ret = ax88179_read_cmd_nopm(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
+				    2, 2, &tmp16);
+
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read MEDIUM_STATUS_MODE: %d\n",
+			   ret);
+		return ret;
+	}
+
 	tmp16 &= ~AX_MEDIUM_RECEIVE_EN;
 	ax88179_write_cmd_nopm(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
 			       2, 2, &tmp16);
 
 	/* Force bulk-in zero length */
-	ax88179_read_cmd_nopm(dev, AX_ACCESS_MAC, AX_PHYPWR_RSTCTL,
-			      2, 2, &tmp16);
+	ret = ax88179_read_cmd_nopm(dev, AX_ACCESS_MAC, AX_PHYPWR_RSTCTL,
+				    2, 2, &tmp16);
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read PHYPWR_RSTCTL: %d\n", ret);
+		return ret;
+	}
 
 	tmp16 |= AX_PHYPWR_RSTCTL_BZ | AX_PHYPWR_RSTCTL_IPRL;
 	ax88179_write_cmd_nopm(dev, AX_ACCESS_MAC, AX_PHYPWR_RSTCTL,
@@ -462,6 +499,7 @@ static int ax88179_auto_detach(struct usbnet *dev, int in_pm)
 {
 	u16 tmp16;
 	u8 tmp8;
+	int ret;
 	int (*fnr)(struct usbnet *, u8, u16, u16, u16, void *);
 	int (*fnw)(struct usbnet *, u8, u16, u16, u16, const void *);
 
@@ -481,11 +519,19 @@ static int ax88179_auto_detach(struct usbnet *dev, int in_pm)
 
 	/* Enable Auto Detach bit */
 	tmp8 = 0;
-	fnr(dev, AX_ACCESS_MAC, AX_CLK_SELECT, 1, 1, &tmp8);
+	ret = fnr(dev, AX_ACCESS_MAC, AX_CLK_SELECT, 1, 1, &tmp8);
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read CLK_SELECT: %d", ret);
+		return ret;
+	}
 	tmp8 |= AX_CLK_SELECT_ULR;
 	fnw(dev, AX_ACCESS_MAC, AX_CLK_SELECT, 1, 1, &tmp8);
 
-	fnr(dev, AX_ACCESS_MAC, AX_PHYPWR_RSTCTL, 2, 2, &tmp16);
+	ret = fnr(dev, AX_ACCESS_MAC, AX_PHYPWR_RSTCTL, 2, 2, &tmp16);
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read PHYPWR_RSTCTL: %d", ret);
+		return ret;
+	}
 	tmp16 |= AX_PHYPWR_RSTCTL_AT;
 	fnw(dev, AX_ACCESS_MAC, AX_PHYPWR_RSTCTL, 2, 2, &tmp16);
 
@@ -497,6 +543,7 @@ static int ax88179_resume(struct usb_interface *intf)
 	struct usbnet *dev = usb_get_intfdata(intf);
 	u16 tmp16;
 	u8 tmp8;
+	int ret;
 
 	usbnet_link_change(dev, 0, 0);
 
@@ -515,7 +562,14 @@ static int ax88179_resume(struct usb_interface *intf)
 	ax88179_auto_detach(dev, 1);
 
 	/* Enable clock */
-	ax88179_read_cmd_nopm(dev, AX_ACCESS_MAC,  AX_CLK_SELECT, 1, 1, &tmp8);
+	ret = ax88179_read_cmd_nopm(dev, AX_ACCESS_MAC,  AX_CLK_SELECT, 1, 1, &tmp8);
+
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read CLK_SELECT %d\n", ret);
+
+		return ret;
+	}
+
 	tmp8 |= AX_CLK_SELECT_ACS | AX_CLK_SELECT_BCS;
 	ax88179_write_cmd_nopm(dev, AX_ACCESS_MAC, AX_CLK_SELECT, 1, 1, &tmp8);
 	msleep(100);
@@ -601,7 +655,7 @@ ax88179_get_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom,
 		ret = __ax88179_read_cmd(dev, AX_ACCESS_EEPROM, i, 1, 2,
 					 &eeprom_buff[i - first_word],
 					 0);
-		if (ret < 0) {
+		if (ret) {
 			kfree(eeprom_buff);
 			return -EIO;
 		}
@@ -645,7 +699,7 @@ ax88179_set_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom,
 	if (eeprom->offset & 1) {
 		ret = ax88179_read_cmd(dev, AX_ACCESS_EEPROM, first_word, 1, 2,
 				       &eeprom_buff[0]);
-		if (ret < 0) {
+		if (ret) {
 			netdev_err(net, "Failed to read EEPROM at offset 0x%02x.\n", first_word);
 			goto free;
 		}
@@ -654,7 +708,7 @@ ax88179_set_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom,
 	if ((eeprom->offset + eeprom->len) & 1) {
 		ret = ax88179_read_cmd(dev, AX_ACCESS_EEPROM, last_word, 1, 2,
 				       &eeprom_buff[last_word - first_word]);
-		if (ret < 0) {
+		if (ret) {
 			netdev_err(net, "Failed to read EEPROM at offset 0x%02x.\n", last_word);
 			goto free;
 		}
@@ -951,23 +1005,45 @@ static int
 ax88179_set_features(struct net_device *net, netdev_features_t features)
 {
 	u8 tmp;
+	int ret;
 	struct usbnet *dev = netdev_priv(net);
 	netdev_features_t changed = net->features ^ features;
 
 	if (changed & NETIF_F_IP_CSUM) {
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL,
+				       1, 1, &tmp);
+		if (ret) {
+			netdev_dbg(dev->net, "Failed to read TXCOE_CTL: %d\n",
+				   ret);
+			return ret;
+		}
+
 		tmp ^= AX_TXCOE_TCP | AX_TXCOE_UDP;
 		ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
 	}
 
 	if (changed & NETIF_F_IPV6_CSUM) {
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL,
+				       1, 1, &tmp);
+		if (ret) {
+			netdev_dbg(dev->net, "Failed to read TXCOE_CTL: %d\n",
+				   ret);
+			return ret;
+		}
+
 		tmp ^= AX_TXCOE_TCPV6 | AX_TXCOE_UDPV6;
 		ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
 	}
 
 	if (changed & NETIF_F_RXCSUM) {
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_RXCOE_CTL, 1, 1, &tmp);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_RXCOE_CTL,
+				       1, 1, &tmp);
+		if (ret) {
+			netdev_dbg(dev->net, "Failed to read TXCOE_CTL: %d\n",
+				   ret);
+			return ret;
+		}
+
 		tmp ^= AX_RXCOE_IP | AX_RXCOE_TCP | AX_RXCOE_UDP |
 		       AX_RXCOE_TCPV6 | AX_RXCOE_UDPV6;
 		ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_RXCOE_CTL, 1, 1, &tmp);
@@ -980,19 +1056,36 @@ static int ax88179_change_mtu(struct net_device *net, int new_mtu)
 {
 	struct usbnet *dev = netdev_priv(net);
 	u16 tmp16;
+	int ret;
 
 	net->mtu = new_mtu;
 	dev->hard_mtu = net->mtu + net->hard_header_len;
 
 	if (net->mtu > 1500) {
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
-				 2, 2, &tmp16);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC,
+				       AX_MEDIUM_STATUS_MODE,
+				       2, 2, &tmp16);
+		if (ret) {
+			netdev_dbg(dev->net,
+				   "Failed to read MEDIUM_STATUS_MODE %d\n",
+				   ret);
+			return ret;
+		}
+
 		tmp16 |= AX_MEDIUM_JUMBO_EN;
 		ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
 				  2, 2, &tmp16);
 	} else {
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
-				 2, 2, &tmp16);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC,
+				       AX_MEDIUM_STATUS_MODE,
+				       2, 2, &tmp16);
+		if (ret) {
+			netdev_dbg(dev->net,
+				   "Failed to read MEDIUM_STATUS_MODE %d\n",
+				   ret);
+			return ret;
+		}
+
 		tmp16 &= ~AX_MEDIUM_JUMBO_EN;
 		ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
 				  2, 2, &tmp16);
@@ -1045,6 +1138,7 @@ static int ax88179_check_eeprom(struct usbnet *dev)
 	u8 i, buf, eeprom[20];
 	u16 csum, delay = HZ / 10;
 	unsigned long jtimeout;
+	int ret;
 
 	/* Read EEPROM content */
 	for (i = 0; i < 6; i++) {
@@ -1060,16 +1154,29 @@ static int ax88179_check_eeprom(struct usbnet *dev)
 
 		jtimeout = jiffies + delay;
 		do {
-			ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
-					 1, 1, &buf);
+			ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
+					       1, 1, &buf);
+			if (ret) {
+				netdev_dbg(dev->net,
+					   "Failed to read SROM_CMD: %d\n",
+					   ret);
+				return ret;
+			}
 
 			if (time_after(jiffies, jtimeout))
 				return -EINVAL;
 
 		} while (buf & EEP_BUSY);
 
-		__ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_LOW,
-				   2, 2, &eeprom[i * 2], 0);
+		ret = __ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_LOW,
+					 2, 2, &eeprom[i * 2], 0);
+
+		if (ret) {
+			netdev_dbg(dev->net,
+				   "Failed to read SROM_DATA_LOW: %d\n",
+				   ret);
+			return ret;
+		}
 
 		if ((i == 0) && (eeprom[0] == 0xFF))
 			return -EINVAL;
@@ -1149,12 +1256,20 @@ static int ax88179_convert_old_led(struct usbnet *dev, u16 *ledvalue)
 
 static int ax88179_led_setting(struct usbnet *dev)
 {
+	int ret;
 	u8 ledfd, value = 0;
 	u16 tmp, ledact, ledlink, ledvalue = 0, delay = HZ / 10;
 	unsigned long jtimeout;
 
 	/* Check AX88179 version. UA1 or UA2*/
-	ax88179_read_cmd(dev, AX_ACCESS_MAC, GENERAL_STATUS, 1, 1, &value);
+	ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, GENERAL_STATUS, 1, 1,
+			       &value);
+
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read GENERAL_STATUS: %d\n",
+			   ret);
+		return ret;
+	}
 
 	if (!(value & AX_SECLD)) {	/* UA1 */
 		value = AX_GPIO_CTRL_GPIO3EN | AX_GPIO_CTRL_GPIO2EN |
@@ -1178,20 +1293,39 @@ static int ax88179_led_setting(struct usbnet *dev)
 
 		jtimeout = jiffies + delay;
 		do {
-			ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
-					 1, 1, &value);
+			ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
+					       1, 1, &value);
+			if (ret) {
+				netdev_dbg(dev->net,
+					   "Failed to read SROM_CMD: %d\n",
+					   ret);
+				return ret;
+			}
 
 			if (time_after(jiffies, jtimeout))
 				return -EINVAL;
 
 		} while (value & EEP_BUSY);
 
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_HIGH,
-				 1, 1, &value);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_HIGH,
+				       1, 1, &value);
+		if (ret) {
+			netdev_dbg(dev->net, "Failed to read SROM_DATA_HIGH: %d\n",
+				   ret);
+			return ret;
+		}
+
 		ledvalue = (value << 8);
 
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_LOW,
-				 1, 1, &value);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_LOW,
+				       1, 1, &value);
+
+		if (ret) {
+			netdev_dbg(dev->net, "Failed to read SROM_DATA_LOW: %d",
+				   ret);
+			return ret;
+		}
+
 		ledvalue |= value;
 
 		/* load internal ROM for defaule setting */
@@ -1213,11 +1347,21 @@ static int ax88179_led_setting(struct usbnet *dev)
 	ax88179_write_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
 			  GMII_PHYPAGE, 2, &tmp);
 
-	ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
-			 GMII_LED_ACT, 2, &ledact);
+	ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
+			       GMII_LED_ACT, 2, &ledact);
 
-	ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
-			 GMII_LED_LINK, 2, &ledlink);
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read PHY_ID: %d", ret);
+		return ret;
+	}
+
+	ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
+			       GMII_LED_LINK, 2, &ledlink);
+
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read PHY_ID: %d", ret);
+		return ret;
+	}
 
 	ledact &= GMII_LED_ACTIVE_MASK;
 	ledlink &= GMII_LED_LINK_MASK;
@@ -1295,6 +1439,7 @@ static int ax88179_led_setting(struct usbnet *dev)
 static void ax88179_get_mac_addr(struct usbnet *dev)
 {
 	u8 mac[ETH_ALEN];
+	int ret;
 
 	memset(mac, 0, sizeof(mac));
 
@@ -1303,8 +1448,12 @@ static void ax88179_get_mac_addr(struct usbnet *dev)
 		netif_dbg(dev, ifup, dev->net,
 			  "MAC address read from device tree");
 	} else {
-		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN,
-				 ETH_ALEN, mac);
+		ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN,
+				       ETH_ALEN, mac);
+
+		if (ret)
+			netdev_dbg(dev->net, "Failed to read NODE_ID: %d", ret);
+
 		netif_dbg(dev, ifup, dev->net,
 			  "MAC address read from ASIX chip");
 	}
@@ -1572,6 +1721,7 @@ static int ax88179_link_reset(struct usbnet *dev)
 	u16 mode, tmp16, delay = HZ / 10;
 	u32 tmp32 = 0x40000000;
 	unsigned long jtimeout;
+	int ret;
 
 	jtimeout = jiffies + delay;
 	while (tmp32 & 0x40000000) {
@@ -1581,7 +1731,13 @@ static int ax88179_link_reset(struct usbnet *dev)
 				  &ax179_data->rxctl);
 
 		/*link up, check the usb device control TX FIFO full or empty*/
-		ax88179_read_cmd(dev, 0x81, 0x8c, 0, 4, &tmp32);
+		ret = ax88179_read_cmd(dev, 0x81, 0x8c, 0, 4, &tmp32);
+
+		if (ret) {
+			netdev_dbg(dev->net, "Failed to read TX FIFO: %d\n",
+				   ret);
+			return ret;
+		}
 
 		if (time_after(jiffies, jtimeout))
 			return 0;
@@ -1590,11 +1746,21 @@ static int ax88179_link_reset(struct usbnet *dev)
 	mode = AX_MEDIUM_RECEIVE_EN | AX_MEDIUM_TXFLOW_CTRLEN |
 	       AX_MEDIUM_RXFLOW_CTRLEN;
 
-	ax88179_read_cmd(dev, AX_ACCESS_MAC, PHYSICAL_LINK_STATUS,
-			 1, 1, &link_sts);
+	ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, PHYSICAL_LINK_STATUS,
+			       1, 1, &link_sts);
+
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read LINK_STATUS: %d", ret);
+		return ret;
+	}
+
+	ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
+			       GMII_PHY_PHYSR, 2, &tmp16);
 
-	ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
-			 GMII_PHY_PHYSR, 2, &tmp16);
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read PHY_ID: %d\n", ret);
+		return ret;
+	}
 
 	if (!(tmp16 & GMII_PHY_PHYSR_LINK)) {
 		return 0;
@@ -1732,9 +1898,16 @@ static int ax88179_reset(struct usbnet *dev)
 static int ax88179_stop(struct usbnet *dev)
 {
 	u16 tmp16;
+	int ret;
+
+	ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
+			       2, 2, &tmp16);
+
+	if (ret) {
+		netdev_dbg(dev->net, "Failed to read STATUS_MODE: %d\n", ret);
+		return ret;
+	}
 
-	ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
-			 2, 2, &tmp16);
 	tmp16 &= ~AX_MEDIUM_RECEIVE_EN;
 	ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
 			  2, 2, &tmp16);
-- 
2.25.1

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com

Tested on:

commit:         33d9269e Revert "kernel: kmsan: don't instrument stack..
git tree:       https://github.com/google/kmsan.git master
kernel config:  https://syzkaller.appspot.com/x/.config?x=d830111cc3be873
dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
compiler:       clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=151cb868f00000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    33d9269ef6e0 Revert "kernel: kmsan: don't instrument stack..
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=158ddbcf700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d830111cc3be873
dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
compiler:       clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=146e3dc3700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com

ax88179_178a 2-1:0.252 (unnamed net_device) (uninitialized): Failed to read reg index 0x0001: -71
ax88179_178a 2-1:0.252 (unnamed net_device) (uninitialized): Failed to read reg index 0x0002: -71
=====================================================
BUG: KMSAN: uninit-value in ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
BUG: KMSAN: uninit-value in ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
 ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_bind+0xf00/0x1a50 drivers/net/usb/ax88179_178a.c:1412
 usbnet_probe+0x1251/0x4160 drivers/net/usb/usbnet.c:1747
 usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396
 really_probe+0x653/0x14b0 drivers/base/dd.c:596
 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:755
 driver_probe_device drivers/base/dd.c:785 [inline]
 __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:902
 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
 __device_attach+0x593/0x8e0 drivers/base/dd.c:973
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1020
 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
 device_add+0x1fff/0x26e0 drivers/base/core.c:3405
 usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170
 usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238
 usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293
 really_probe+0x653/0x14b0 drivers/base/dd.c:596
 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:755
 driver_probe_device drivers/base/dd.c:785 [inline]
 __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:902
 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
 __device_attach+0x593/0x8e0 drivers/base/dd.c:973
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1020
 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
 device_add+0x1fff/0x26e0 drivers/base/core.c:3405
 usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2566
 hub_port_connect drivers/usb/core/hub.c:5358 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5502 [inline]
 port_event drivers/usb/core/hub.c:5660 [inline]
 hub_event+0x58e3/0x89e0 drivers/usb/core/hub.c:5742
 process_one_work+0xdb6/0x1820 kernel/workqueue.c:2307
 worker_thread+0x10b3/0x21e0 kernel/workqueue.c:2454
 kthread+0x3c7/0x500 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

Local variable eeprom.i created at:
 ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1045 [inline]
 ax88179_led_setting+0x2e2/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_bind+0xf00/0x1a50 drivers/net/usb/ax88179_178a.c:1412

CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.17.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
=====================================================

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[David Kahurani]

On Sat, Mar 26, 2022 at 3:43 PM Pavel Skripkin <paskripkin@gmail.com> wrote:
>
> Hi David,
>
> On 3/26/22 14:47, David Kahurani wrote:
> >>
> >> Signed-off-by: David Kahurani <k.kahurani@gmail.com>
> >> Reported-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com
> >> ---
> >>  drivers/net/usb/ax88179_178a.c | 181 +++++++++++++++++++++++++++------
> >>  1 file changed, 152 insertions(+), 29 deletions(-)
> >>
> >> diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
> >> index a31098981..932e21a65 100644
> >> --- a/drivers/net/usb/ax88179_178a.c
> >> +++ b/drivers/net/usb/ax88179_178a.c
> >> @@ -224,9 +224,12 @@ static int __ax88179_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
> >>   ret = fn(dev, cmd, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> >>   value, index, data, size);
> >>
>

Yes, this breaks the logic of the entire patch. It was a mistake. Will
fix that alongside your other comments.

> You've changed __ax88179_write_cmd(), but not __ax88179_read_cmd(). I've
> missed it. Changing  __ax88179_write_cmd() does not help with uninit
> value bugs
>
> Also I believe, __ax88179_read_cmd() should have __must_check annotation
> too, since problem came from it in the first place (I mean after added
> sane error handling inside it)
>
> Next thing is ax88179_read_cmd_nopm() still prone to uninit value bugs,
> since it touches uninitialized `buf` in case of __ax88179_read_cmd()
> error...
>
>
>
> I remembered why I gave up on fixing this driver... I hope, you have
> more free time and motivation :)
>
>
>
>
> With regards,
> Pavel Skripkin

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[Pavel Skripkin]

Hi David,

On 3/26/22 14:47, David Kahurani wrote:
>>
>> Signed-off-by: David Kahurani <k.kahurani@gmail.com>
>> Reported-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com
>> ---
>>  drivers/net/usb/ax88179_178a.c | 181 +++++++++++++++++++++++++++------
>>  1 file changed, 152 insertions(+), 29 deletions(-)
>>
>> diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
>> index a31098981..932e21a65 100644
>> --- a/drivers/net/usb/ax88179_178a.c
>> +++ b/drivers/net/usb/ax88179_178a.c
>> @@ -224,9 +224,12 @@ static int __ax88179_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
>>   ret = fn(dev, cmd, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
>>   value, index, data, size);
>>

You've changed __ax88179_write_cmd(), but not __ax88179_read_cmd(). I've 
missed it. Changing  __ax88179_write_cmd() does not help with uninit 
value bugs

Also I believe, __ax88179_read_cmd() should have __must_check annotation 
too, since problem came from it in the first place (I mean after added 
sane error handling inside it)

Next thing is ax88179_read_cmd_nopm() still prone to uninit value bugs, 
since it touches uninitialized `buf` in case of __ax88179_read_cmd() 
error...



I remembered why I gave up on fixing this driver... I hope, you have 
more free time and motivation :)




With regards,
Pavel Skripkin

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[Pavel Skripkin]

Hi David,

On 3/26/22 14:47, David Kahurani wrote:
> Same here. My apologies.
> 
> On Sat, Mar 26, 2022 at 2:28 PM David Kahurani <k.kahurani@gmail.com> wrote:
>>
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 85cfd6e539bd kmsan: core: delete kmsan_gup_pgd_range()
>> git tree: https://github.com/google/kmsan.git master
>> console output: https://syzkaller.appspot.com/x/log.txt?x=12d6c53c700000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=b9807dd5b044fd7a
>> dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
>> compiler: clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
>>
>> Based off a previous patch to fix a similar issue.
>> -------------------------

Looks sane.

Can you, please, send it as proper patch with explanation in commit 
message and with a bit cutted log, since full ->probe() calltrace is not 
interesting :)




With regards,
Pavel Skripkin

Re: [syzbot] KMSAN: uninit-value in ax88179_led_setting

[David Kahurani]

Same here. My apologies.

On Sat, Mar 26, 2022 at 2:28 PM David Kahurani <k.kahurani@gmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 85cfd6e539bd kmsan: core: delete kmsan_gup_pgd_range()
> git tree: https://github.com/google/kmsan.git master
> console output: https://syzkaller.appspot.com/x/log.txt?x=12d6c53c700000
> kernel config: https://syzkaller.appspot.com/x/.config?x=b9807dd5b044fd7a
> dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
> compiler: clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
>
> Based off a previous patch to fix a similar issue.
> -------------------------
>
> From: David Kahurani <k.kahurani@gmail.com>
> Date: Sat, 26 Mar 2022 14:19:47 +0300
> Subject: [PATCH] net: ax88179: add proper error handling of usb read errors
>
> ax88179_178a 2-1:0.35 (unnamed net_device) (uninitialized): Failed to read reg index 0x0001: -71
> ax88179_178a 2-1:0.35 (unnamed net_device) (uninitialized): Failed to read reg index 0x0002: -71
> =====================================================
> BUG: KMSAN: uninit-value in ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
> BUG: KMSAN: uninit-value in ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
>  ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
>  ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
>  ax88179_bind+0xe75/0x1990 drivers/net/usb/ax88179_178a.c:1411
>  usbnet_probe+0x1284/0x4140 drivers/net/usb/usbnet.c:1747
>  usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396
>  really_probe+0x67d/0x1510 drivers/base/dd.c:596
>  __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
>  driver_probe_device drivers/base/dd.c:781 [inline]
>  __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
>  bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
>  __device_attach+0x593/0x8e0 drivers/base/dd.c:969
>  device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
>  bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
>  device_add+0x1d3e/0x2400 drivers/base/core.c:3394
>  usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170
>  usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238
>  usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293
>  really_probe+0x67d/0x1510 drivers/base/dd.c:596
>  __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
>  driver_probe_device drivers/base/dd.c:781 [inline]
>  __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
>  bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
>  __device_attach+0x593/0x8e0 drivers/base/dd.c:969
>  device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
>  bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
>  device_add+0x1d3e/0x2400 drivers/base/core.c:3394
>  usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2563
>  hub_port_connect drivers/usb/core/hub.c:5353 [inline]
>  hub_port_connect_change drivers/usb/core/hub.c:5497 [inline]
>  port_event drivers/usb/core/hub.c:5643 [inline]
>  hub_event+0x5ad2/0x8910 drivers/usb/core/hub.c:5725
>  process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
>  process_scheduled_works kernel/workqueue.c:2361 [inline]
>  worker_thread+0x1735/0x21f0 kernel/workqueue.c:2447
>  kthread+0x721/0x850 kernel/kthread.c:327
>  ret_from_fork+0x1f/0x30
>
> Local variable eeprom.i created at:
>  ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1045 [inline]
>  ax88179_led_setting+0x2e2/0x30b0 drivers/net/usb/ax88179_178a.c:1168
>  ax88179_bind+0xe75/0x1990 drivers/net/usb/ax88179_178a.c:1411
>
> CPU: 1 PID: 13457 Comm: kworker/1:0 Not tainted 5.16.0-rc5-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> =====================================================
>
> Signed-off-by: David Kahurani <k.kahurani@gmail.com>
> Reported-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com
> ---
>  drivers/net/usb/ax88179_178a.c | 181 +++++++++++++++++++++++++++------
>  1 file changed, 152 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
> index a31098981..932e21a65 100644
> --- a/drivers/net/usb/ax88179_178a.c
> +++ b/drivers/net/usb/ax88179_178a.c
> @@ -224,9 +224,12 @@ static int __ax88179_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
>   ret = fn(dev, cmd, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
>   value, index, data, size);
>
> - if (unlikely(ret < 0))
> + if (unlikely(ret < size)) {
> +        ret = ret < 0 ? ret : -ENODATA;
> +
>   netdev_warn(dev->net, "Failed to write reg index 0x%04x: %d\n",
>      index, ret);
> + }
>
>   return ret;
>  }
> @@ -290,8 +293,8 @@ static int ax88179_write_cmd_nopm(struct usbnet *dev, u8 cmd, u16 value,
>   return ret;
>  }
>
> -static int ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
> -    u16 size, void *data)
> +static int __must_check ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value,
> +                                         u16 index, u16 size, void *data)
>  {
>   int ret;
>
> @@ -354,8 +357,15 @@ static int ax88179_mdio_read(struct net_device *netdev, int phy_id, int loc)
>  {
>   struct usbnet *dev = netdev_priv(netdev);
>   u16 res;
> + int ret;
> +
> + ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, phy_id, (__u16)loc, 2, &res);
> +
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read PHY_ID: %d\n", ret);
> + return ret;
> + }
>
> - ax88179_read_cmd(dev, AX_ACCESS_PHY, phy_id, (__u16)loc, 2, &res);
>   return res;
>  }
>
> @@ -951,23 +961,45 @@ static int
>  ax88179_set_features(struct net_device *net, netdev_features_t features)
>  {
>   u8 tmp;
> + int ret;
>   struct usbnet *dev = netdev_priv(net);
>   netdev_features_t changed = net->features ^ features;
>
>   if (changed & NETIF_F_IP_CSUM) {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL,
> +       1, 1, &tmp);
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read TXCOE_CTL: %d\n",
> +   ret);
> + return ret;
> + }
> +
>   tmp ^= AX_TXCOE_TCP | AX_TXCOE_UDP;
>   ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
>   }
>
>   if (changed & NETIF_F_IPV6_CSUM) {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL,
> +       1, 1, &tmp);
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read TXCOE_CTL: %d\n",
> +   ret);
> + return ret;
> + }
> +
>   tmp ^= AX_TXCOE_TCPV6 | AX_TXCOE_UDPV6;
>   ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_TXCOE_CTL, 1, 1, &tmp);
>   }
>
>   if (changed & NETIF_F_RXCSUM) {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_RXCOE_CTL, 1, 1, &tmp);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_RXCOE_CTL,
> +       1, 1, &tmp);
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read TXCOE_CTL: %d\n",
> +   ret);
> + return ret;
> + }
> +
>   tmp ^= AX_RXCOE_IP | AX_RXCOE_TCP | AX_RXCOE_UDP |
>         AX_RXCOE_TCPV6 | AX_RXCOE_UDPV6;
>   ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_RXCOE_CTL, 1, 1, &tmp);
> @@ -980,19 +1012,36 @@ static int ax88179_change_mtu(struct net_device *net, int new_mtu)
>  {
>   struct usbnet *dev = netdev_priv(net);
>   u16 tmp16;
> + int ret;
>
>   net->mtu = new_mtu;
>   dev->hard_mtu = net->mtu + net->hard_header_len;
>
>   if (net->mtu > 1500) {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
> - 2, 2, &tmp16);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC,
> +       AX_MEDIUM_STATUS_MODE,
> +       2, 2, &tmp16);
> + if (ret < 0){
> + netdev_dbg(dev->net,
> +   "Failed to read MEDIUM_STATUS_MODE %d\n",
> +   ret);
> + return ret;
> + }
> +
>   tmp16 |= AX_MEDIUM_JUMBO_EN;
>   ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
>    2, 2, &tmp16);
>   } else {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
> - 2, 2, &tmp16);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC,
> +               AX_MEDIUM_STATUS_MODE,
> +       2, 2, &tmp16);
> + if (ret < 0){
> + netdev_dbg(dev->net,
> +   "Failed to read MEDIUM_STATUS_MODE %d\n",
> +   ret);
> + return ret;
> + }
> +
>   tmp16 &= ~AX_MEDIUM_JUMBO_EN;
>   ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
>    2, 2, &tmp16);
> @@ -1045,6 +1094,7 @@ static int ax88179_check_eeprom(struct usbnet *dev)
>   u8 i, buf, eeprom[20];
>   u16 csum, delay = HZ / 10;
>   unsigned long jtimeout;
> + int ret;
>
>   /* Read EEPROM content */
>   for (i = 0; i < 6; i++) {
> @@ -1060,8 +1110,15 @@ static int ax88179_check_eeprom(struct usbnet *dev)
>
>   jtimeout = jiffies + delay;
>   do {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> - 1, 1, &buf);
> +    ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> +   1, 1, &buf);
> +
> +    if (ret < 0) {
> +    netdev_dbg(dev->net,
> +       "Failed to read SROM_CMD: %d\n",
> +               ret);
> +    return ret;
> +    }
>
>   if (time_after(jiffies, jtimeout))
>   return -EINVAL;
> @@ -1149,12 +1206,19 @@ static int ax88179_convert_old_led(struct usbnet *dev, u16 *ledvalue)
>
>  static int ax88179_led_setting(struct usbnet *dev)
>  {
> + int ret;
>   u8 ledfd, value = 0;
>   u16 tmp, ledact, ledlink, ledvalue = 0, delay = HZ / 10;
>   unsigned long jtimeout;
>
>   /* Check AX88179 version. UA1 or UA2*/
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, GENERAL_STATUS, 1, 1, &value);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, GENERAL_STATUS, 1, 1, &value);
> +
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read GENERAL_STATUS: %d\n",
> +   ret);
> + return ret;
> + }
>
>   if (!(value & AX_SECLD)) { /* UA1 */
>   value = AX_GPIO_CTRL_GPIO3EN | AX_GPIO_CTRL_GPIO2EN |
> @@ -1178,20 +1242,40 @@ static int ax88179_led_setting(struct usbnet *dev)
>
>   jtimeout = jiffies + delay;
>   do {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> - 1, 1, &value);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_CMD,
> +       1, 1, &value);
> + if (ret < 0){
> + netdev_dbg(dev->net,
> +   "Failed to read SROM_CMD: %d\n",
> +   ret);
> + return ret;
> + }
>
>   if (time_after(jiffies, jtimeout))
>   return -EINVAL;
>
>   } while (value & EEP_BUSY);
>
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_HIGH,
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_HIGH,
>   1, 1, &value);
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read SROM_DATA_HIGH: %d\n",
> +   ret);
> + return ret;
> + }
> +
> +
>   ledvalue = (value << 8);
>
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_LOW,
> - 1, 1, &value);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_SROM_DATA_LOW,
> +       1, 1, &value);
> +
> + if (ret < 0) {
> + netdev_dbg(dev->net, "Failed to read SROM_DATA_LOW: %d",
> +   ret);
> + return ret;
> + }
> +
>   ledvalue |= value;
>
>   /* load internal ROM for defaule setting */
> @@ -1213,12 +1297,22 @@ static int ax88179_led_setting(struct usbnet *dev)
>   ax88179_write_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
>    GMII_PHYPAGE, 2, &tmp);
>
> - ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
> - GMII_LED_ACT, 2, &ledact);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
> +       GMII_LED_ACT, 2, &ledact);
> +
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read PHY_ID: %d", ret);
> + return ret;
> + }
>
> - ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
> + ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
>   GMII_LED_LINK, 2, &ledlink);
>
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read PHY_ID: %d", ret);
> + return ret;
> + }
> +
>   ledact &= GMII_LED_ACTIVE_MASK;
>   ledlink &= GMII_LED_LINK_MASK;
>
> @@ -1295,6 +1389,7 @@ static int ax88179_led_setting(struct usbnet *dev)
>  static void ax88179_get_mac_addr(struct usbnet *dev)
>  {
>   u8 mac[ETH_ALEN];
> + int ret;
>
>   memset(mac, 0, sizeof(mac));
>
> @@ -1303,8 +1398,12 @@ static void ax88179_get_mac_addr(struct usbnet *dev)
>   netif_dbg(dev, ifup, dev->net,
>    "MAC address read from device tree");
>   } else {
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN,
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN,
>   ETH_ALEN, mac);
> +
> + if (ret < 0)
> + netdev_dbg(dev->net, "Failed to read NODE_ID: %d", ret);
> +
>   netif_dbg(dev, ifup, dev->net,
>    "MAC address read from ASIX chip");
>   }
> @@ -1572,6 +1671,7 @@ static int ax88179_link_reset(struct usbnet *dev)
>   u16 mode, tmp16, delay = HZ / 10;
>   u32 tmp32 = 0x40000000;
>   unsigned long jtimeout;
> + int ret;
>
>   jtimeout = jiffies + delay;
>   while (tmp32 & 0x40000000) {
> @@ -1581,7 +1681,13 @@ static int ax88179_link_reset(struct usbnet *dev)
>    &ax179_data->rxctl);
>
>   /*link up, check the usb device control TX FIFO full or empty*/
> - ax88179_read_cmd(dev, 0x81, 0x8c, 0, 4, &tmp32);
> + ret = ax88179_read_cmd(dev, 0x81, 0x8c, 0, 4, &tmp32);
> +
> + if (ret < 0) {
> + netdev_dbg(dev->net, "Failed to read TX FIFO: %d\n",
> +   ret);
> + return ret;
> + }
>
>   if (time_after(jiffies, jtimeout))
>   return 0;
> @@ -1590,11 +1696,21 @@ static int ax88179_link_reset(struct usbnet *dev)
>   mode = AX_MEDIUM_RECEIVE_EN | AX_MEDIUM_TXFLOW_CTRLEN |
>         AX_MEDIUM_RXFLOW_CTRLEN;
>
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, PHYSICAL_LINK_STATUS,
> - 1, 1, &link_sts);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, PHYSICAL_LINK_STATUS,
> +       1, 1, &link_sts);
> +
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read LINK_STATUS: %d", ret);
> + return ret;
> + }
>
> - ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
> - GMII_PHY_PHYSR, 2, &tmp16);
> + ret = ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID,
> +       GMII_PHY_PHYSR, 2, &tmp16);
> +
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read PHY_ID: %d\n", ret);
> + return ret;
> + }
>
>   if (!(tmp16 & GMII_PHY_PHYSR_LINK)) {
>   return 0;
> @@ -1732,9 +1848,16 @@ static int ax88179_reset(struct usbnet *dev)
>  static int ax88179_stop(struct usbnet *dev)
>  {
>   u16 tmp16;
> + int ret;
>
> - ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
> + ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
>   2, 2, &tmp16);
> +
> + if (ret < 0){
> + netdev_dbg(dev->net, "Failed to read STATUS_MODE: %d\n", ret);
> + return ret;
> + }
> +
>   tmp16 &= ~AX_MEDIUM_RECEIVE_EN;
>   ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
>    2, 2, &tmp16);
> --
> 2.25.1

[syzbot] KMSAN: uninit-value in ax88179_led_setting

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    85cfd6e539bd kmsan: core: delete kmsan_gup_pgd_range()
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=12d6c53c700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b9807dd5b044fd7a
dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
compiler:       clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d3dbdf31fbe9d8f5f311@syzkaller.appspotmail.com

ax88179_178a 2-1:0.35 (unnamed net_device) (uninitialized): Failed to read reg index 0x0001: -71
ax88179_178a 2-1:0.35 (unnamed net_device) (uninitialized): Failed to read reg index 0x0002: -71
=====================================================
BUG: KMSAN: uninit-value in ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
BUG: KMSAN: uninit-value in ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
 ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_bind+0xe75/0x1990 drivers/net/usb/ax88179_178a.c:1411
 usbnet_probe+0x1284/0x4140 drivers/net/usb/usbnet.c:1747
 usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396
 really_probe+0x67d/0x1510 drivers/base/dd.c:596
 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
 driver_probe_device drivers/base/dd.c:781 [inline]
 __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
 __device_attach+0x593/0x8e0 drivers/base/dd.c:969
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
 device_add+0x1d3e/0x2400 drivers/base/core.c:3394
 usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170
 usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238
 usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293
 really_probe+0x67d/0x1510 drivers/base/dd.c:596
 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
 driver_probe_device drivers/base/dd.c:781 [inline]
 __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
 __device_attach+0x593/0x8e0 drivers/base/dd.c:969
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
 device_add+0x1d3e/0x2400 drivers/base/core.c:3394
 usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2563
 hub_port_connect drivers/usb/core/hub.c:5353 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5497 [inline]
 port_event drivers/usb/core/hub.c:5643 [inline]
 hub_event+0x5ad2/0x8910 drivers/usb/core/hub.c:5725
 process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
 process_scheduled_works kernel/workqueue.c:2361 [inline]
 worker_thread+0x1735/0x21f0 kernel/workqueue.c:2447
 kthread+0x721/0x850 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

Local variable eeprom.i created at:
 ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1045 [inline]
 ax88179_led_setting+0x2e2/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_bind+0xe75/0x1990 drivers/net/usb/ax88179_178a.c:1411

CPU: 1 PID: 13457 Comm: kworker/1:0 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
=====================================================


---
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