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Message-ID: <9153f947ee3fe7c7ab5d1ad2a6760c4485b82bea.camel@kernel.org>
Subject: Re: [PATCH] NFSD: fix use-after-free in nfsd4_ssc_setup_dul()
From:   Jeff Layton <jlayton@kernel.org>
To:     Xingyuan Mo <hdthky0@gmail.com>, chuck.lever@oracle.com
Cc:     linux-nfs@vger.kernel.org, dai.ngo@oracle.com
Date:   Wed, 11 Jan 2023 11:31:04 -0500
In-Reply-To: <20230111162453.8295-1-hdthky0@gmail.com>
References: <20230111162453.8295-1-hdthky0@gmail.com>
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On Thu, 2023-01-12 at 00:24 +0800, Xingyuan Mo wrote:
> If signal_pending() returns true, schedule_timeout() will not be executed=
,
> causing the waiting task to remain in the wait queue.
> Fixed by adding a call to finish_wait(), which ensures that the waiting
> task will always be removed from the wait queue.
>=20
> Reported-by: Xingyuan Mo <hdthky0@gmail.com>
> Signed-off-by: Xingyuan Mo <hdthky0@gmail.com>
> ---
>  fs/nfsd/nfs4proc.c | 1 +
>  1 file changed, 1 insertion(+)
>=20
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index bd880d55f565..3fa819e29b3f 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1318,6 +1318,7 @@ static __be32 nfsd4_ssc_setup_dul(struct nfsd_net *=
nn, char *ipaddr,
>  			/* allow 20secs for mount/unmount for now - revisit */
>  			if (signal_pending(current) ||
>  					(schedule_timeout(20*HZ) =3D=3D 0)) {
> +				finish_wait(&nn->nfsd_ssc_waitq, &wait);
>  				kfree(work);
>  				return nfserr_eagain;
>  			}

Nice catch.

Reviewed-by: Jeff Layton <jlayton@kernel.org>