From: Christian Brauner Date: Mon, 23 Aug 2021 15:13:51 +0000 (+0200) Subject: ksmbd: fix translation in acl entries X-Git-Tag: accepted/tizen/unified/20230118.172025~6404^2~13 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0e844efebdf9c03aed9ae1894f22762a8aee1a3b;p=platform%2Fkernel%2Flinux-rpi.git ksmbd: fix translation in acl entries The ksmbd server performs translation of posix acls to smb acls. Currently the translation is wrong since the idmapping of the mount is used to map the ids into raw userspace ids but what is relevant is the user namespace of ksmbd itself. The user namespace of ksmbd itself which is the initial user namespace. The operation is similar to asking "What *ids would a userspace process see given that k*id in the relevant user namespace?". Before the final translation we need to apply the idmapping of the mount in case any is used. Add two simple helpers for ksmbd. Cc: Steve French Cc: Christoph Hellwig Cc: Namjae Jeon Cc: Hyunchul Lee Cc: Sergey Senozhatsky Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c index a7025b3..3307ca7 100644 --- a/fs/ksmbd/smbacl.c +++ b/fs/ksmbd/smbacl.c @@ -587,14 +587,14 @@ static void set_posix_acl_entries_dacl(struct user_namespace *user_ns, uid_t uid; unsigned int sid_type = SIDOWNER; - uid = from_kuid(user_ns, pace->e_uid); + uid = posix_acl_uid_translate(user_ns, pace); if (!uid) sid_type = SIDUNIX_USER; id_to_sid(uid, sid_type, sid); } else if (pace->e_tag == ACL_GROUP) { gid_t gid; - gid = from_kgid(user_ns, pace->e_gid); + gid = posix_acl_gid_translate(user_ns, pace); id_to_sid(gid, SIDUNIX_GROUP, sid); } else if (pace->e_tag == ACL_OTHER && !nt_aces_num) { smb_copy_sid(sid, &sid_everyone); @@ -653,12 +653,12 @@ posix_default_acl: if (pace->e_tag == ACL_USER) { uid_t uid; - uid = from_kuid(user_ns, pace->e_uid); + uid = posix_acl_uid_translate(user_ns, pace); id_to_sid(uid, SIDCREATOR_OWNER, sid); } else if (pace->e_tag == ACL_GROUP) { gid_t gid; - gid = from_kgid(user_ns, pace->e_gid); + gid = posix_acl_gid_translate(user_ns, pace); id_to_sid(gid, SIDCREATOR_GROUP, sid); } else { kfree(sid); @@ -1234,11 +1234,9 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path, pa_entry = posix_acls->a_entries; for (i = 0; i < posix_acls->a_count; i++, pa_entry++) { if (pa_entry->e_tag == ACL_USER) - id = from_kuid(user_ns, - pa_entry->e_uid); + id = posix_acl_uid_translate(user_ns, pa_entry); else if (pa_entry->e_tag == ACL_GROUP) - id = from_kgid(user_ns, - pa_entry->e_gid); + id = posix_acl_gid_translate(user_ns, pa_entry); else continue; diff --git a/fs/ksmbd/smbacl.h b/fs/ksmbd/smbacl.h index 940f686..73e08ca 100644 --- a/fs/ksmbd/smbacl.h +++ b/fs/ksmbd/smbacl.h @@ -209,4 +209,29 @@ int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon, bool type_check); void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid); void ksmbd_init_domain(u32 *sub_auth); + +static inline uid_t posix_acl_uid_translate(struct user_namespace *mnt_userns, + struct posix_acl_entry *pace) +{ + kuid_t kuid; + + /* If this is an idmapped mount, apply the idmapping. */ + kuid = kuid_into_mnt(mnt_userns, pace->e_uid); + + /* Translate the kuid into a userspace id ksmbd would see. */ + return from_kuid(&init_user_ns, kuid); +} + +static inline gid_t posix_acl_gid_translate(struct user_namespace *mnt_userns, + struct posix_acl_entry *pace) +{ + kgid_t kgid; + + /* If this is an idmapped mount, apply the idmapping. */ + kgid = kgid_into_mnt(mnt_userns, pace->e_gid); + + /* Translate the kgid into a userspace id ksmbd would see. */ + return from_kgid(&init_user_ns, kgid); +} + #endif /* _SMBACL_H */ diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c index 2bb506d..b047f29 100644 --- a/fs/ksmbd/vfs.c +++ b/fs/ksmbd/vfs.c @@ -1390,14 +1390,14 @@ static struct xattr_smb_acl *ksmbd_vfs_make_xattr_posix_acl(struct user_namespac switch (pa_entry->e_tag) { case ACL_USER: xa_entry->type = SMB_ACL_USER; - xa_entry->uid = from_kuid(user_ns, pa_entry->e_uid); + xa_entry->uid = posix_acl_uid_translate(user_ns, pa_entry); break; case ACL_USER_OBJ: xa_entry->type = SMB_ACL_USER_OBJ; break; case ACL_GROUP: xa_entry->type = SMB_ACL_GROUP; - xa_entry->gid = from_kgid(user_ns, pa_entry->e_gid); + xa_entry->gid = posix_acl_gid_translate(user_ns, pa_entry); break; case ACL_GROUP_OBJ: xa_entry->type = SMB_ACL_GROUP_OBJ;