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Message-ID: <cbd4bc97-4ffb-45c5-8c3c-b9b81b20d813@linux.alibaba.com>
Date:   Fri, 6 Jan 2023 13:06:07 +0800
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Subject: Re: [PATCH] erofs: fix kvcalloc() misuse with __GFP_NOFAIL
To:     linux-erofs@lists.ozlabs.org, Chao Yu <chao@kernel.org>,
        Yue Hu <huyue2@coolpad.com>,
        Jeffle Xu <jefflexu@linux.alibaba.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        syzbot+c3729cda01706a04fb98@syzkaller.appspotmail.com
References: <20230106031937.113318-1-hsiangkao@linux.alibaba.com>
From:   Gao Xiang <hsiangkao@linux.alibaba.com>
In-Reply-To: <20230106031937.113318-1-hsiangkao@linux.alibaba.com>
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On 2023/1/6 11:19, Gao Xiang wrote:
> As reported by syzbot [1], kvcalloc() cannot work with  __GFP_NOFAIL.
> Let's use kcalloc() instead.
> 
> [1] https://lore.kernel.org/r/0000000000007796bd05f1852ec2@google.com
> Reported-by: syzbot+c3729cda01706a04fb98@syzkaller.appspotmail.com

Fixes: fe3e5914e6dc ("erofs: try to leave (de)compressed_pages on stack if possible")
Fixes: 4f05687fd703 ("erofs: introduce struct z_erofs_decompress_backend")

> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> ---
>   fs/erofs/zdata.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index ccf7c55d477f..08e982c77985 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -1032,12 +1032,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
>   
>   	if (!be->decompressed_pages)
>   		be->decompressed_pages =
> -			kvcalloc(be->nr_pages, sizeof(struct page *),
> -				 GFP_KERNEL | __GFP_NOFAIL);
> +			kcalloc(be->nr_pages, sizeof(struct page *),
> +				GFP_KERNEL | __GFP_NOFAIL);
>   	if (!be->compressed_pages)
>   		be->compressed_pages =
> -			kvcalloc(pclusterpages, sizeof(struct page *),
> -				 GFP_KERNEL | __GFP_NOFAIL);
> +			kcalloc(pclusterpages, sizeof(struct page *),
> +				GFP_KERNEL | __GFP_NOFAIL);
>   
>   	z_erofs_parse_out_bvecs(be);
>   	err2 = z_erofs_parse_in_bvecs(be, &overlapped);