From 7860484eeb9051910f023ee2762041a125fec797 Mon Sep 17 00:00:00 2001
From: Andrew Lunn <andrew@lunn.ch>
Date: Sun, 24 Oct 2021 21:48:05 +0200
Subject: [PATCH] phy: phy_ethtool_ksettings_set: Lock the PHY while changing settings
Git-commit: af1a02aa23c37045e6adfcf074cf7dbac167a403
Patch-mainline: v5.15
References: stable-5.14.16
commit af1a02aa23c37045e6adfcf074cf7dbac167a403 upstream.
There is a race condition where the PHY state machine can change
members of the phydev structure at the same time userspace requests a
change via ethtool. To prevent this, have phy_ethtool_ksettings_set
take the PHY lock.
Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support")
Reported-by: Walter Stoll <Walter.Stoll@duagon.com>
Suggested-by: Walter Stoll <Walter.Stoll@duagon.com>
Tested-by: Walter Stoll <Walter.Stoll@duagon.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/phy/phy.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 197a8ec38ea3..cbf344c5db61 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -798,6 +798,7 @@ int phy_ethtool_ksettings_set(struct phy_device *phydev,
duplex != DUPLEX_FULL)))
return -EINVAL;
+ mutex_lock(&phydev->lock);
phydev->autoneg = autoneg;
if (autoneg == AUTONEG_DISABLE) {
@@ -814,8 +815,9 @@ int phy_ethtool_ksettings_set(struct phy_device *phydev,
phydev->mdix_ctrl = cmd->base.eth_tp_mdix_ctrl;
/* Restart the PHY */
- phy_start_aneg(phydev);
+ _phy_start_aneg(phydev);
+ mutex_unlock(&phydev->lock);
return 0;
}
EXPORT_SYMBOL(phy_ethtool_ksettings_set);
--
2.26.2