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* [PATCH net] phylib: fix potential use-after-free
@ 2022-01-19 16:27 Marek Behún
  2022-01-20  0:27 ` Andrew Lunn
  2022-01-21  6:00 ` patchwork-bot+netdevbpf
  0 siblings, 2 replies; 3+ messages in thread
From: Marek Behún @ 2022-01-19 16:27 UTC (permalink / raw)
  To: netdev
  Cc: Russell King, Andrew Lunn, Sergei Shtylyov, David S . Miller,
	Marek Behún

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@kernel.org>
---
 drivers/net/phy/phy_device.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 74d8e1dc125f..ce0bb5951b81 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);
 
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH net] phylib: fix potential use-after-free
  2022-01-19 16:27 [PATCH net] phylib: fix potential use-after-free Marek Behún
@ 2022-01-20  0:27 ` Andrew Lunn
  2022-01-21  6:00 ` patchwork-bot+netdevbpf
  1 sibling, 0 replies; 3+ messages in thread
From: Andrew Lunn @ 2022-01-20  0:27 UTC (permalink / raw)
  To: Marek Behún; +Cc: netdev, Russell King, Sergei Shtylyov, David S . Miller

On Wed, Jan 19, 2022 at 05:27:48PM +0100, Marek Behún wrote:
> 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@kernel.org>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH net] phylib: fix potential use-after-free
  2022-01-19 16:27 [PATCH net] phylib: fix potential use-after-free Marek Behún
  2022-01-20  0:27 ` Andrew Lunn
@ 2022-01-21  6:00 ` patchwork-bot+netdevbpf
  1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-01-21  6:00 UTC (permalink / raw)
  To: =?utf-8?q?Marek_Beh=C3=BAn_=3Ckabel=40kernel=2Eorg=3E?=
  Cc: netdev, rmk+kernel, andrew, sergei.shtylyov, davem

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 19 Jan 2022 17:27:48 +0100 you wrote:
> 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().
> 
> [...]

Here is the summary with links:
  - [net] phylib: fix potential use-after-free
    https://git.kernel.org/netdev/net/c/cbda1b166875

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 3+ messages in thread

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2022-01-19 16:27 [PATCH net] phylib: fix potential use-after-free Marek Behún
2022-01-20  0:27 ` Andrew Lunn
2022-01-21  6:00 ` patchwork-bot+netdevbpf

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