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Message-ID: <15d5da65079d072856ef5e8d88040df2095bb6b7.camel@huaweicloud.com>
Subject: Re: [PATCH] um: Add winch to winch_handlers before registering
 winch IRQ
From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: Johannes Berg <johannes@sipsolutions.net>, richard@nod.at, 
	anton.ivanov@cambridgegreys.com
Cc: linux-kernel@vger.kernel.org, linux-um@lists.infradead.org, Roberto
 Sassu <roberto.sassu@huawei.com>
Date: Tue, 23 Apr 2024 09:22:31 +0200
In-Reply-To: <1743ad022502d64042fa7db4d847a988bb90cbdc.camel@sipsolutions.net>
References: <20240307104926.3531358-1-roberto.sassu@huaweicloud.com>
	 <1743ad022502d64042fa7db4d847a988bb90cbdc.camel@sipsolutions.net>
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On Thu, 2024-03-28 at 09:25 +0100, Johannes Berg wrote:
> On Thu, 2024-03-07 at 11:49 +0100, Roberto Sassu wrote:
> > From: Roberto Sassu <roberto.sassu@huawei.com>
> >=20
> > Registering a winch IRQ is racy, an interrupt may occur before the winc=
h is
> > added to the winch_handlers list.
> >=20
> > If that happens, register_winch_irq() adds to that list a winch that is
> > scheduled to be (or has already been) freed, causing a panic later in
> > winch_cleanup().
> >=20
> > Avoid the race by adding the winch to the winch_handlers list before
> > registering the IRQ, and rolling back if um_request_irq() fails.
> >=20
>=20
> Reviewed-by: Johannes Berg <johannes@sipsolutions.net>

Thank you! Richard, are you going to pick this up?

Thanks

Roberto