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References: <20240105193331.1180331-1-xzou017@ucr.edu>
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From: Tigran Aivazian <aivazian.tigran@gmail.com>
Date: Sat, 6 Jan 2024 08:38:02 +0000
Message-ID: <CAK+_RLm93haEd13Z0hVPSRqG4STsDHMHfu4FBdaBW1QP0m_c6w@mail.gmail.com>
Subject: Re: [PATCH] fs/bfs: Null check to prevent null-ptr-deref bug
To: Xiaochen Zou <xzou017@ucr.edu>
Cc: linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"

Hello,

On Fri, 5 Jan 2024 at 19:33, Xiaochen Zou <xzou017@ucr.edu> wrote:
> Similar to ea2b62f3058 (fs/sysv: Null check to prevent
> null-ptr-deref bug), bfs is lack of return value check for
> sb_getblk(). Adding a null check to prevent null-ptr-defer bug

> diff --git a/fs/bfs/file.c b/fs/bfs/file.c
> index adc2230079c6..35688424bde3 100644
> --- a/fs/bfs/file.c
> +++ b/fs/bfs/file.c
> @@ -39,6 +39,8 @@ static int bfs_move_block(unsigned long from, unsigned long to,
>         if (!bh)
>                 return -EIO;
>         new = sb_getblk(sb, to);
> +       if (unlikely(!new))
> +               return -ENOMEM;

Thank you, yes, that makes sense. Please apply the patch.

Acknowledged-By; Tigran Aivazian <aivazian.tigran@gmail.com>