[PATCH net] net: usb: lan78xx: fix use of improperly initialized dev->chipid in lan78xx_reset
From: I Viswanath <hidden>
Date: 2025-10-01 13:14:25
Also in:
linux-kernel-mentees, linux-usb, lkml
Subsystem:
networking drivers, the rest, usb lan78xx ethernet driver, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Thangaraj Samynathan, Rengarajan Sundararajan
dev->chipid is used in lan78xx_init_mac_address before it's initialized:
lan78xx_reset() {
lan78xx_init_mac_address()
lan78xx_read_eeprom()
lan78xx_read_raw_eeprom() <- dev->chipid is used here
dev->chipid = ... <- dev->chipid is initialized correctly here
}
Reorder initialization so that dev->chipid is set before calling
lan78xx_init_mac_address().
Signed-off-by: I Viswanath <redacted>
---
KMSAN didn't detect this issue because dev->chipid is zero
initialized from alloc_etherdev
drivers/net/usb/lan78xx.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 1ff25f57329a..f3831ecaaec1 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c@@ -3238,10 +3238,6 @@ static int lan78xx_reset(struct lan78xx_net *dev) } } while (buf & HW_CFG_LRST_); - ret = lan78xx_init_mac_address(dev); - if (ret < 0) - return ret; - /* save DEVID for later usage */ ret = lan78xx_read_reg(dev, ID_REV, &buf); if (ret < 0)
@@ -3250,6 +3246,10 @@ static int lan78xx_reset(struct lan78xx_net *dev) dev->chipid = (buf & ID_REV_CHIP_ID_MASK_) >> 16; dev->chiprev = buf & ID_REV_CHIP_REV_MASK_; + ret = lan78xx_init_mac_address(dev); + if (ret < 0) + return ret; + /* Respond to the IN token with a NAK */ ret = lan78xx_read_reg(dev, USB_CFG0, &buf); if (ret < 0)
--
2.47.3