6.18-stable review patch. If anyone has any objections, please let me know.
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From: Deepanshu Kartikey kartikey406@gmail.com
[ Upstream commit a1e077a3f76eea0dc671ed6792e7d543946227e8 ]
The ASIX driver reads the PHY address from the USB device via asix_read_phy_addr(). A malicious or faulty device can return an invalid address (>= PHY_MAX_ADDR), which causes a warning in mdiobus_get_phy():
addr 207 out of range WARNING: drivers/net/phy/mdio_bus.c:76
Validate the PHY address in asix_read_phy_addr() and remove the now-redundant check in ax88172a.c.
Reported-by: syzbot+3d43c9066a5b54902232@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3d43c9066a5b54902232 Tested-by: syzbot+3d43c9066a5b54902232@syzkaller.appspotmail.com Fixes: 7e88b11a862a ("net: usb: asix: refactor asix_read_phy_addr() and handle errors on return") Link: https://lore.kernel.org/all/20251217085057.270704-1-kartikey406@gmail.com/T/ [v1] Signed-off-by: Deepanshu Kartikey kartikey406@gmail.com Reviewed-by: Andrew Lunn andrew@lunn.ch Link: https://patch.msgid.link/20251218011156.276824-1-kartikey406@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/asix_common.c | 5 +++++ drivers/net/usb/ax88172a.c | 6 +----- 2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c index 7fd763917ae2..6ab3486072cb 100644 --- a/drivers/net/usb/asix_common.c +++ b/drivers/net/usb/asix_common.c @@ -335,6 +335,11 @@ int asix_read_phy_addr(struct usbnet *dev, bool internal) offset = (internal ? 1 : 0); ret = buf[offset];
+ if (ret >= PHY_MAX_ADDR) { + netdev_err(dev->net, "invalid PHY address: %d\n", ret); + return -ENODEV; + } + netdev_dbg(dev->net, "%s PHY address 0x%x\n", internal ? "internal" : "external", ret);
diff --git a/drivers/net/usb/ax88172a.c b/drivers/net/usb/ax88172a.c index f613e4bc68c8..758a423a459b 100644 --- a/drivers/net/usb/ax88172a.c +++ b/drivers/net/usb/ax88172a.c @@ -210,11 +210,7 @@ static int ax88172a_bind(struct usbnet *dev, struct usb_interface *intf) ret = asix_read_phy_addr(dev, priv->use_embdphy); if (ret < 0) goto free; - if (ret >= PHY_MAX_ADDR) { - netdev_err(dev->net, "Invalid PHY address %#x\n", ret); - ret = -ENODEV; - goto free; - } + priv->phy_addr = ret;
ax88172a_reset_phy(dev, priv->use_embdphy);