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From:   Ilya Dryomov <idryomov@gmail.com>
Date:   Tue, 14 Jun 2022 12:03:56 +0200
Message-ID: <CAOi1vP-xXk7SSkaQJziv-9j=WfpXYdVieaBmfsJXTnPTYDTOjQ@mail.gmail.com>
Subject: Re: [PATCH] libceph: check pointer before assigned to "c->rules[]"
To:     Li Qiong <liqiong@nfschina.com>
Cc:     Xiubo Li <xiubli@redhat.com>, Jeff Layton <jlayton@kernel.org>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Ceph Development <ceph-devel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, yuzhe@nfschina.com,
        renyu@nfschina.com
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On Tue, Jun 14, 2022 at 9:12 AM Li Qiong <liqiong@nfschina.com> wrote:
>
> It should be better to check pointer firstly, then assign it
> to c->rules[]. Refine code a little bit.
>
> Signed-off-by: Li Qiong <liqiong@nfschina.com>
> ---
>  net/ceph/osdmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
> index 2823bb3cff55..6ec5007f96dc 100644
> --- a/net/ceph/osdmap.c
> +++ b/net/ceph/osdmap.c
> @@ -571,9 +571,9 @@ static struct crush_map *crush_decode(void *pbyval, void *end)
>                         goto bad;
>  #endif
>                 r = kmalloc(struct_size(r, steps, yes), GFP_NOFS);
> -               c->rules[i] = r;
>                 if (r == NULL)
>                         goto badmem;
> +               c->rules[i] = r;
>                 dout(" rule %d is at %p\n", i, r);
>                 r->len = yes;
>                 ceph_decode_copy_safe(p, end, &r->mask, 4, bad); /* 4 u8's */
> --
> 2.11.0
>

This doesn't change anything as c->rules pointer array is zeroed out.
Anyway, applied.

Thanks,

                Ilya