[lxc-devel] [PATCH] Fix to work lxc-destroy with unprivileged containers on recent kernel

[KATOH Yasufumi]

Hi,

I applied this patch and test. lxc-destroy work fine. :-)

>>> On Sat, 28 Jun 2014 18:39:54 +0900
    in message   "[lxc-devel] [PATCH] Fix to work lxc-destroy with unprivileged	containers on recent kernel"
                  TAMUKI Shoichi-san wrote:

> Change idmap_add_id() to add both ID_TYPE_UID and ID_TYPE_GID entries
> to an existing lxc_conf, not just an ID_TYPE_UID entry, so as to work
> lxc-destroy with unprivileged containers on recent kernel.

> Signed-off-by: TAMUKI Shoichi <tamuki at linet.gr.jp>

Acked-by: KATOH Yasufumi <karma at jazz.email.ne.jp>

> ---
>  src/lxc/conf.c | 49 ++++++++++++++++++++++++++++++++++---------------
>  1 file changed, 34 insertions(+), 15 deletions(-)

> diff --git a/src/lxc/conf.c b/src/lxc/conf.c
> index df2f7cc..70f57af 100644
> --- a/src/lxc/conf.c
> +++ b/src/lxc/conf.c
> @@ -4508,14 +4508,14 @@ static int run_userns_fn(void *data)
>  }
 
>  /*
> - * Add a ID_TYPE_UID entry to an existing lxc_conf, if it is not
> - * alread there.
> - * We may want to generalize this to do gids as well as uids, but right now
> - * it's not necessary.
> + * Add ID_TYPE_UID/ID_TYPE_GID entries to an existing lxc_conf,
> + * if they are not already there.
>   */
> -static struct lxc_list *idmap_add_id(struct lxc_conf *conf, uid_t uid)
> +static struct lxc_list *idmap_add_id(struct lxc_conf *conf,
> +		uid_t uid, gid_t gid)
>  {
> -	int hostid_mapped = mapped_hostid(uid, conf, ID_TYPE_UID);
> +	int hostuid_mapped = mapped_hostid(uid, conf, ID_TYPE_UID);
> +	int hostgid_mapped = mapped_hostid(gid, conf, ID_TYPE_GID);
>  	struct lxc_list *new = NULL, *tmp, *it, *next;
>  	struct id_map *entry;
 
> @@ -4526,9 +4526,9 @@ static struct lxc_list *idmap_add_id(struct lxc_conf *conf, uid_t uid)
>  	}
>  	lxc_list_init(new);
 
> -	if (hostid_mapped < 0) {
> -		hostid_mapped = find_unmapped_nsuid(conf, ID_TYPE_UID);
> -		if (hostid_mapped < 0)
> +	if (hostuid_mapped < 0) {
> +		hostuid_mapped = find_unmapped_nsuid(conf, ID_TYPE_UID);
> +		if (hostuid_mapped < 0)
>  			goto err;
>  		tmp = malloc(sizeof(*tmp));
>  		if (!tmp)
> @@ -4540,8 +4540,27 @@ static struct lxc_list *idmap_add_id(struct lxc_conf *conf, uid_t uid)
>  		}
>  		tmp->elem = entry;
>  		entry->idtype = ID_TYPE_UID;
> -		entry->nsid = hostid_mapped;
> -		entry->hostid = (unsigned long)uid;
> +		entry->nsid = hostuid_mapped;
> +		entry->hostid = (unsigned long) uid;
> +		entry->range = 1;
> +		lxc_list_add_tail(new, tmp);
> +	}
> +	if (hostgid_mapped < 0) {
> +		hostgid_mapped = find_unmapped_nsuid(conf, ID_TYPE_GID);
> +		if (hostgid_mapped < 0)
> +			goto err;
> +		tmp = malloc(sizeof(*tmp));
> +		if (!tmp)
> +			goto err;
> +		entry = malloc(sizeof(*entry));
> +		if (!entry) {
> +			free(tmp);
> +			goto err;
> +		}
> +		tmp->elem = entry;
> +		entry->idtype = ID_TYPE_GID;
> +		entry->nsid = hostgid_mapped;
> +		entry->hostid = (unsigned long) gid;
>  		entry->range = 1;
>  		lxc_list_add_tail(new, tmp);
>  	}
> @@ -4563,7 +4582,7 @@ static struct lxc_list *idmap_add_id(struct lxc_conf *conf, uid_t uid)
>  	return new;
 
>  err:
> -	ERROR("Out of memory building a new uid map");
> +	ERROR("Out of memory building a new uid/gid map");
>  	if (new)
>  		lxc_free_idmap(new);
>  	free(new);
> @@ -4572,7 +4591,7 @@ err:
 
>  /*
>   * Run a function in a new user namespace.
> - * The caller's euid will be mapped in if it is not already.
> + * The caller's euid/egid will be mapped in if it is not already.
>   */
>  int userns_exec_1(struct lxc_conf *conf, int (*fn)(void *), void *data)
>  {
> @@ -4597,8 +4616,8 @@ int userns_exec_1(struct lxc_conf *conf, int (*fn)(void *), void *data)
>  	close(p[0]);
>  	p[0] = -1;
 
> -	if ((idmap = idmap_add_id(conf, geteuid())) == NULL) {
> -		ERROR("Error adding self to container uid map");
> +	if ((idmap = idmap_add_id(conf, geteuid(), getegid())) == NULL) {
> +		ERROR("Error adding self to container uid/gid map");
>  		goto err;
>  	}
 
> -- 
> 1.9.0
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