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From:   Olga Kornievskaia <aglo@umich.edu>
Date:   Mon, 5 Aug 2019 12:38:45 -0400
Message-ID: <CAN-5tyGWuJgZN-riN2A-mKuwobCe8USWv6mCXLZfE8i=Je-XwA@mail.gmail.com>
Subject: Re: [PATCH] NFSv4: Fix an Oops in nfs4_do_setattr
To:     Trond Myklebust <trondmy@gmail.com>
Cc:     linux-nfs <linux-nfs@vger.kernel.org>
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On Sat, Aug 3, 2019 at 10:45 AM Trond Myklebust <trondmy@gmail.com> wrote:
>
> If the user specifies an open mode of 3, then we don't have a NFSv4 state
> attached to the context, and so we Oops when we try to dereference it.
>
> Reported-by: Olga Kornievskaia <aglo@umich.edu>
> Fixes: 29b59f9416937 ("NFSv4: change nfs4_do_setattr to take...")
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> Cc: stable@vger.kernel.org # v4.10: 991eedb1371dc: NFSv4: Only pass the...
> Cc: stable@vger.kernel.org # v4.10+
> ---
>  fs/nfs/nfs4proc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 3e0b93f2b61a..12b2b65ad8a8 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -3214,7 +3214,7 @@ static int _nfs4_do_setattr(struct inode *inode,
>
>         if (nfs4_copy_delegation_stateid(inode, FMODE_WRITE, &arg->stateid, &delegation_cred)) {
>                 /* Use that stateid */
> -       } else if (ctx != NULL) {
> +       } else if (ctx != NULL && ctx->state) {
>                 struct nfs_lock_context *l_ctx;
>                 if (!nfs4_valid_open_stateid(ctx->state))
>                         return -EBADF;

Thank you Trond. No longer oops-ing with this patch.

> --
> 2.21.0
>