diff options
| author | Heiner Kallweit <hkallweit1@gmail.com> | 2019-02-13 20:12:54 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-02-14 12:04:55 -0500 |
| commit | a20049071796691cf99eb6433968fc3c27632b95 (patch) | |
| tree | 5c4576e502af6717242dee142475bf318856d0cc | |
| parent | a2fc9d7e36f6d484d9be4a0a204400aaf6059544 (diff) | |
| download | linux-a20049071796691cf99eb6433968fc3c27632b95.tar.bz2 | |
net: phy: fix potential race in the phylib state machine
Russell reported the following race in the phylib state machine
(quoting from his mail):
if (phy_polling_mode(phydev) && phy_is_started(phydev))
phy_queue_state_machine(phydev, PHY_STATE_TIME);
state = PHY_UP
thread 0 thread 1
phy_disconnect()
+-phy_is_started()
phy_is_started() |
`-phy_stop()
+-phydev->state = PHY_HALTED
`-phy_stop_machine()
`-cancel_delayed_work_sync()
phy_queue_state_machine()
`-mod_delayed_work()
At this point, the phydev->state_queue() has been added back onto the
system workqueue despite phy_stop_machine() having been called and
cancel_delayed_work_sync() called on it.
Fix this by protecting the complete operation in thread 0.
Fixes: 2b3e88ea6528 ("net: phy: improve phy state checking")
Reported-by: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/phy/phy.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 602816d70281..c5675df5fc6f 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -985,8 +985,10 @@ void phy_state_machine(struct work_struct *work) * state machine would be pointless and possibly error prone when * called from phy_disconnect() synchronously. */ + mutex_lock(&phydev->lock); if (phy_polling_mode(phydev) && phy_is_started(phydev)) phy_queue_state_machine(phydev, PHY_STATE_TIME); + mutex_unlock(&phydev->lock); } /** |