This is a note to let you know that I've just added the patch titled
phylib: fix potential use-after-free
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
phylib-fix-potential-use-after-free.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2764544d3074d7e07b19608d75284209baaecd8a
Author: Marek Behún <kabel@xxxxxxxxxx>
Date: Wed Jan 19 17:27:48 2022 +0100
phylib: fix potential use-after-free
[ Upstream commit cbda1b16687580d5beee38273f6241ae3725960c ]
Commit bafbdd527d56 ("phylib: Add device reset GPIO support") added call
to phy_device_reset(phydev) after the put_device() call in phy_detach().
The comment before the put_device() call says that the phydev might go
away with put_device().
Fix potential use-after-free by calling phy_device_reset() before
put_device().
Fixes: bafbdd527d56 ("phylib: Add device reset GPIO support")
Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Link: https://lore.kernel.org/r/20220119162748.32418-1-kabel@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 74d8e1dc125f8..ce0bb5951b81e 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1746,6 +1746,9 @@ void phy_detach(struct phy_device *phydev)
phy_driver_is_genphy_10g(phydev))
device_release_driver(&phydev->mdio.dev);
+ /* Assert the reset signal */
+ phy_device_reset(phydev, 1);
+
/*
* The phydev might go away on the put_device() below, so avoid
* a use-after-free bug by reading the underlying bus first.
@@ -1757,9 +1760,6 @@ void phy_detach(struct phy_device *phydev)
ndev_owner = dev->dev.parent->driver->owner;
if (ndev_owner != bus->owner)
module_put(bus->owner);
-
- /* Assert the reset signal */
- phy_device_reset(phydev, 1);
}
EXPORT_SYMBOL(phy_detach);
