Re: [PATCH] erofs: fix kvcalloc() misuse with __GFP_NOFAIL

Gao Xiang
2023-01-06T05:06:18Z

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);