Re: [PATCH V2] fscrypt: don't set policy for a dead directory

[Eric Biggers <ebiggers@kernel.org>]

On Wed, May 08, 2019 at 05:27:34PM +0800, hongjiefang wrote:
> the directory maybe has been removed when enter fscrypt_ioctl_set_policy().
> it this case, the empty_dir() check will return error for ext4 file system.
> 
> ext4_rmdir() sets i_size = 0, then ext4_empty_dir() reports an error
> because 'inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)'.
> if the fs is mounted with errors=panic, it will trigger a panic issue.
> 
> add the check IS_DEADDIR() to fix this problem.
> 
> Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support")
> Cc: <stable@vger.kernel.org> # v4.1+
> Signed-off-by: hongjiefang <hongjiefang@asrmicro.com>

Reviewed-by: Eric Biggers <ebiggers@google.com>

FYI, the part of the Author and Signed-off-by lines outside the email address
should be your name properly formatted, not the email address again.  I see the
following in another kernel commit from you; is it correct?

	Hongjie Fang <hongjiefang@asrmicro.com>

If so, please set user.name accordingly in your .gitconfig.  Thanks!

- Eric

> ---
>  fs/crypto/policy.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
> index bd7eaf9..a4eca6e 100644
> --- a/fs/crypto/policy.c
> +++ b/fs/crypto/policy.c
> @@ -81,6 +81,8 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
>  	if (ret == -ENODATA) {
>  		if (!S_ISDIR(inode->i_mode))
>  			ret = -ENOTDIR;
> +		else if (IS_DEADDIR(inode))
> +			ret = -ENOENT;
>  		else if (!inode->i_sb->s_cop->empty_dir(inode))
>  			ret = -ENOTEMPTY;
>  		else
> -- 
> 1.9.1
>