Re: [PATCH] erofs: fix uninitialized page cache reported by KMSAN

[Chao Yu]

On 2024/3/4 11:53, Gao Xiang wrote:
> syzbot reports a KMSAN reproducer [1] which generates a crafted
> filesystem image and causes IMA to read uninitialized page cache.
>
> Later, (rq->outputsize > rq->inputsize) will be formally supported
> after either large uncompressed pclusters (> block size) or big
> lclusters are landed.  However, currently there is no way to generate
> such filesystems by using mkfs.erofs.
>
> Thus, let's mark this condition as unsupported for now.
>
> [1] https://lore.kernel.org/r/0000000000002be12a0611ca7ff8@xxxxxxxxxx
>
> Reported-by: syzbot+7bc44a489f0ef0670bd5@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 1ca01520148a ("erofs: refine z_erofs_transform_plain() for sub-page block support")
> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,