Re: [PATCH 2/2] ext4: reject encrypted inodes when block size > page size

[Baokun Li <libaokun@linux.alibaba.com>]

On 2026/9/25 22:19, Alberto Garcia wrote:
> Encryption is not supported when a filesystem's block size is larger
> than the page size. ext4_check_large_folio() refuses to mount a
> filesystem like that if the "encrypt" feature is already enabled, and
> ext4_set_context() refuses to create encrypted inodes if the feature
> is enabled after mounting.
>
> However, a corrupted or hand-crafted filesystem can still have
> encrypted inodes even if the "encrypt" feature is not set, and those
> inodes can be unlocked if they're using v1 policies.
>
> Check this in __ext4_iget() and reject them as corrupted.
>
> Fixes: 709f0f1f1bf5 ("ext4: add checks for large folio incompatibilities when BS > PS")
> Suggested-by: Eric Biggers <ebiggers@kernel.org>
> Cc: stable@vger.kernel.org # v6.19+
> Signed-off-by: Alberto Garcia <berto@igalia.com>

Looks good, feel free to add:

Reviewed-by: Baokun Li <libaokun@linux.alibaba.com>

> ---
>  fs/ext4/inode.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 26f0f9714f03..31248fef8bce 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -5671,6 +5671,12 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
>  		ret = -EFSCORRUPTED;
>  		goto bad_inode;
>  	}
> +	if (IS_ENCRYPTED(inode) && sb->s_blocksize > PAGE_SIZE) {
> +		ext4_error_inode(inode, function, line, 0,
> +				 "encrypted inode with block size larger than page size");
> +		ret = -EFSCORRUPTED;
> +		goto bad_inode;
> +	}
>  
>  	ext4_set_inode_mapping_order(inode);
>