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From: Pavel Skripkin <>
Subject: Re: [PATCH] phy: mdio: fix memory leak
Date: Mon, 27 Sep 2021 22:17:51 +0300	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 9/27/21 14:20, Pavel Skripkin wrote:
> Syzbot reported memory leak in MDIO bus interface, the problem was in
> wrong state logic.
> MDIOBUS_ALLOCATED indicates 2 states:
> 	1. Bus is only allocated
> 	2. Bus allocated and __mdiobus_register() fails, but
> 	   device_register() was called
> In case of device_register() has been called we should call put_device()
> to correctly free the memory allocated for this device, but mdiobus_free()
> was just calling kfree(dev) in case of MDIOBUS_ALLOCATED state
> To avoid this behaviour we can add new intermediate state, which means,
> that we have called device_regiter(), but failed on any of the next steps.
> Clean up process for this state is the same as for MDIOBUS_UNREGISTERED,
> but MDIOBUS_UNREGISTERED name does not fit to the logic described above.
> Fixes: 46abc02175b3 ("phylib: give mdio buses a device tree presence")
> Reported-and-tested-by:
> Signed-off-by: Pavel Skripkin <>

I've just found, that this syzkaller bug has been closed by Yanfei's 
patch [1], but Yanfei's Reported-by: is wrong, IMO.

Yanfei's patch fixed other memory leak and it's not related to bug 
reported by syzkaller. If you take a look at log [2] you won't find 
error message about mii_bus registration failure, i.e the error happened 
a bit latter (more precisely in mdiobus_scan()).

Since, Yanfei's patch is already applied, we cannot remove this tag, so 
I am informing you about this situation to break possible confusions 
about 2 different patches with same Reported-by: tag :)




With regards,
Pavel Skripkin

  reply	other threads:[~2021-09-27 19:17 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-27 11:20 Pavel Skripkin
2021-09-27 19:17 ` Pavel Skripkin [this message]
2021-09-28 20:39 ` [PATCH v2 1/2] Revert "net: mdiobus: Fix memory leak in __mdiobus_register" Pavel Skripkin
2021-09-28 20:40   ` [PATCH v2 2/2] phy: mdio: fix memory leak Pavel Skripkin
2021-09-29  6:22     ` Dan Carpenter
2021-09-29 23:48     ` Jakub Kicinski
2021-09-30  5:55       ` Pavel Skripkin
2021-09-29  6:32   ` [PATCH v2 1/2] Revert "net: mdiobus: Fix memory leak in __mdiobus_register" Xu, Yanfei

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