[PATCH 2/3] ubifs: xattr: preserve the encryption flag when creation fails

[Zhihao Cheng]

在 2026/11/2 19:56, shao.mingyin at zte.com.cn 写道:
> create_xattr() clears UBIFS_CRYPT_FL in its error path regardless of
> whether this call set the flag.  The flag is also set for every inode
> that already carries an encryption context, so a failed setxattr() on
> such an inode clears it from the in-memory inode.  The next inode write
> then packs ui->flags without UBIFS_CRYPT_FL, and after the next mount
> the inode is no longer treated as encrypted although its names and data
> still are.  ubifs_jnl_update() can fail before anything is written, for
> example when its journal buffer cannot be allocated.
> 
> Remember whether this call actually set the flag and only clear it in
> that case.
> 
> Fixes: d475a507457b ("ubifs: Add skeleton for fscrypto")
> Cc: stable at vger.kernel.org
> Signed-off-by: Shao Mingyin <shao.mingyin at zte.com.cn>
> ---
Reviewed-by: Zhihao Cheng <chengzhihao1 at huawei.com>
> diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
> index 3b0e8a270f59..7f82ddb9e3f2 100644
> --- a/fs/ubifs/xattr.c
> +++ b/fs/ubifs/xattr.c
> @@ -69,6 +69,7 @@ static int create_xattr(struct ubifs_info *c, struct inode *host,
>   			const struct fscrypt_name *nm, const void *value, int size)
>   {
>   	int err, names_len;
> +	bool set_crypt = false;
>   	struct inode *inode;
>   	struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
>   	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
> @@ -133,8 +134,10 @@ static int create_xattr(struct ubifs_info *c, struct inode *host,
>   	 * To avoid multiple updates of the same inode in the same operation,
>   	 * let's do it here.
>   	 */
> -	if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
> +	if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) {
> +		set_crypt = !(host_ui->flags & UBIFS_CRYPT_FL);
>   		host_ui->flags |= UBIFS_CRYPT_FL;
> +	}
>   
>   	err = ubifs_jnl_update(c, host, nm, inode, 0, 1, 0);
>   	if (err)
> @@ -152,7 +155,8 @@ static int create_xattr(struct ubifs_info *c, struct inode *host,
>   	host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
>   	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
>   	host_ui->xattr_names -= fname_len(nm);
> -	host_ui->flags &= ~UBIFS_CRYPT_FL;
> +	if (set_crypt)
> +		host_ui->flags &= ~UBIFS_CRYPT_FL;
>   	mutex_unlock(&host_ui->ui_mutex);
>   out_free:
>   	make_bad_inode(inode);
> .
>