Re: [PATCH] fs/bfs: Null check to prevent null-ptr-deref bug

From: Tigran Aivazian
Date: Sat Jan 06 2024 - 03:38:24 EST


Hello,

On Fri, 5 Jan 2024 at 19:33, Xiaochen Zou <xzou017@xxxxxxx> 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@xxxxxxxxx>