diff options
| author | Oleksij Rempel <o.rempel@pengutronix.de> | 2025-06-26 12:37:31 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-07-01 12:42:51 +0200 |
| commit | c22f056e49d905d54a0203a32e344dc422766e38 (patch) | |
| tree | df86e02d083aa18b5158a8c837cb2f54b60dc987 /drivers/net/usb/lan78xx.c | |
| parent | 8f240030794ca027fa669b447c0f27ffd8ae72d5 (diff) | |
net: usb: lan78xx: fix possible NULL pointer dereference in lan78xx_phy_init()
If no PHY device is found (e.g., for LAN7801 in fixed-link mode),
lan78xx_phy_init() may proceed to dereference a NULL phydev pointer,
leading to a crash.
Update the logic to perform MAC configuration first, then check for the presence
of a PHY. For the fixed-link case, set up the fixed link and return early,
bypassing any code that assumes a valid phydev pointer.
It is safe to move lan78xx_mac_prepare_for_phy() earlier because this function
only uses information from dev->interface, which is configured by
lan78xx_get_phy() beforehand. The function does not access phydev or any data
set up by later steps.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Fixes: e110bc825897 ("net: usb: lan78xx: Convert to PHYLINK for improved PHY and MAC management")
Link: https://patch.msgid.link/20250626103731.3986545-1-o.rempel@pengutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'drivers/net/usb/lan78xx.c')
| -rw-r--r-- | drivers/net/usb/lan78xx.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index f00284c9ad34..f3347fb0c400 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -2831,6 +2831,10 @@ static int lan78xx_phy_init(struct lan78xx_net *dev) if (ret < 0) return ret; + ret = lan78xx_mac_prepare_for_phy(dev); + if (ret < 0) + goto phylink_uninit; + /* If no PHY is found, set up a fixed link. It is very specific to * the LAN7801 and is used in special cases like EVB-KSZ9897-1 where * LAN7801 acts as a USB-to-Ethernet interface to a switch without @@ -2840,11 +2844,12 @@ static int lan78xx_phy_init(struct lan78xx_net *dev) ret = lan78xx_set_fixed_link(dev); if (ret < 0) goto phylink_uninit; - } - ret = lan78xx_mac_prepare_for_phy(dev); - if (ret < 0) - goto phylink_uninit; + /* No PHY found, so set up a fixed link and return early. + * No need to configure PHY IRQ or attach to phylink. + */ + return 0; + } /* if phyirq is not set, use polling mode in phylib */ if (dev->domain_data.phyirq > 0) |