// SPDX-License-Identifier: LGPL-2.1+ /* * Copyright (C) International Business Machines Corp., 2007,2008 * Author(s): Steve French (sfrench@us.ibm.com) * Copyright (C) 2020 Samsung Electronics Co., Ltd. * Author(s): Namjae Jeon */ #include #include #include #include "smbacl.h" #include "smb_common.h" #include "server.h" #include "misc.h" #include "mgmt/share_config.h" static const struct smb_sid domain = {1, 4, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(21), cpu_to_le32(1), cpu_to_le32(2), cpu_to_le32(3), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; /* security id for everyone/world system group */ static const struct smb_sid creator_owner = { 1, 1, {0, 0, 0, 0, 0, 3}, {0} }; /* security id for everyone/world system group */ static const struct smb_sid creator_group = { 1, 1, {0, 0, 0, 0, 0, 3}, {cpu_to_le32(1)} }; /* security id for everyone/world system group */ static const struct smb_sid sid_everyone = { 1, 1, {0, 0, 0, 0, 0, 1}, {0} }; /* security id for Authenticated Users system group */ static const struct smb_sid sid_authusers = { 1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(11)} }; /* S-1-22-1 Unmapped Unix users */ static const struct smb_sid sid_unix_users = {1, 1, {0, 0, 0, 0, 0, 22}, {cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; /* S-1-22-2 Unmapped Unix groups */ static const struct smb_sid sid_unix_groups = { 1, 1, {0, 0, 0, 0, 0, 22}, {cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; /* * See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx */ /* S-1-5-88 MS NFS and Apple style UID/GID/mode */ /* S-1-5-88-1 Unix uid */ static const struct smb_sid sid_unix_NFS_users = { 1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(88), cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; /* S-1-5-88-2 Unix gid */ static const struct smb_sid sid_unix_NFS_groups = { 1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(88), cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; /* S-1-5-88-3 Unix mode */ static const struct smb_sid sid_unix_NFS_mode = { 1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(88), cpu_to_le32(3), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; /* * if the two SIDs (roughly equivalent to a UUID for a user or group) are * the same returns zero, if they do not match returns non-zero. */ int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid) { int i; int num_subauth, num_sat, num_saw; if (!ctsid || !cwsid) return 1; /* compare the revision */ if (ctsid->revision != cwsid->revision) { if (ctsid->revision > cwsid->revision) return 1; else return -1; } /* compare all of the six auth values */ for (i = 0; i < NUM_AUTHS; ++i) { if (ctsid->authority[i] != cwsid->authority[i]) { if (ctsid->authority[i] > cwsid->authority[i]) return 1; else return -1; } } /* compare all of the subauth values if any */ num_sat = ctsid->num_subauth; num_saw = cwsid->num_subauth; num_subauth = num_sat < num_saw ? num_sat : num_saw; if (num_subauth) { for (i = 0; i < num_subauth; ++i) { if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) { if (le32_to_cpu(ctsid->sub_auth[i]) > le32_to_cpu(cwsid->sub_auth[i])) return 1; else return -1; } } } return 0; /* sids compare/match */ } static void smb_copy_sid(struct smb_sid *dst, const struct smb_sid *src) { int i; dst->revision = src->revision; dst->num_subauth = min_t(u8, src->num_subauth, SID_MAX_SUB_AUTHORITIES); for (i = 0; i < NUM_AUTHS; ++i) dst->authority[i] = src->authority[i]; for (i = 0; i < dst->num_subauth; ++i) dst->sub_auth[i] = src->sub_auth[i]; } /* * change posix mode to reflect permissions * pmode is the existing mode (we only want to overwrite part of this * bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007 */ static umode_t access_flags_to_mode(struct smb_fattr *fattr, __le32 ace_flags, int type) { __u32 flags = le32_to_cpu(ace_flags); umode_t mode = 0; if (flags & GENERIC_ALL) { mode = 0777; ksmbd_debug(SMB, "all perms\n"); return mode; } if ((flags & GENERIC_READ) || (flags & FILE_READ_RIGHTS)) mode = 0444; if ((flags & GENERIC_WRITE) || (flags & FILE_WRITE_RIGHTS)) { mode |= 0222; if (S_ISDIR(fattr->cf_mode)) mode |= 0111; } if ((flags & GENERIC_EXECUTE) || (flags & FILE_EXEC_RIGHTS)) mode |= 0111; if (type == ACCESS_DENIED_ACE_TYPE || type == ACCESS_DENIED_OBJECT_ACE_TYPE) mode = ~mode; ksmbd_debug(SMB, "access flags 0x%x mode now %04o\n", flags, mode); return mode; } /* * Generate access flags to reflect permissions mode is the existing mode. * This function is called for every ACE in the DACL whose SID matches * with either owner or group or everyone. */ static void mode_to_access_flags(umode_t mode, umode_t bits_to_use, __u32 *pace_flags) { /* reset access mask */ *pace_flags = 0x0; /* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */ mode &= bits_to_use; /* * check for R/W/X UGO since we do not know whose flags * is this but we have cleared all the bits sans RWX for * either user or group or other as per bits_to_use */ if (mode & 0444) *pace_flags |= SET_FILE_READ_RIGHTS; if (mode & 0222) *pace_flags |= FILE_WRITE_RIGHTS; if (mode & 0111) *pace_flags |= SET_FILE_EXEC_RIGHTS; ksmbd_debug(SMB, "mode: %o, access flags now 0x%x\n", mode, *pace_flags); } static __u16 fill_ace_for_sid(struct smb_ace *pntace, const struct smb_sid *psid, int type, int flags, umode_t mode, umode_t bits) { int i; __u16 size = 0; __u32 access_req = 0; pntace->type = type; pntace->flags = flags; mode_to_access_flags(mode, bits, &access_req); if (!access_req) access_req = SET_MINIMUM_RIGHTS; pntace->access_req = cpu_to_le32(access_req); pntace->sid.revision = psid->revision; pntace->sid.num_subauth = psid->num_subauth; for (i = 0; i < NUM_AUTHS; i++) pntace->sid.authority[i] = psid->authority[i]; for (i = 0; i < psid->num_subauth; i++) pntace->sid.sub_auth[i] = psid->sub_auth[i]; size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4); pntace->size = cpu_to_le16(size); return size; } void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid) { switch (sidtype) { case SIDOWNER: smb_copy_sid(ssid, &server_conf.domain_sid); break; case SIDUNIX_USER: smb_copy_sid(ssid, &sid_unix_users); break; case SIDUNIX_GROUP: smb_copy_sid(ssid, &sid_unix_groups); break; case SIDCREATOR_OWNER: smb_copy_sid(ssid, &creator_owner); return; case SIDCREATOR_GROUP: smb_copy_sid(ssid, &creator_group); return; case SIDNFS_USER: smb_copy_sid(ssid, &sid_unix_NFS_users); break; case SIDNFS_GROUP: smb_copy_sid(ssid, &sid_unix_NFS_groups); break; case SIDNFS_MODE: smb_copy_sid(ssid, &sid_unix_NFS_mode); break; default: return; } /* RID */ ssid->sub_auth[ssid->num_subauth] = cpu_to_le32(cid); ssid->num_subauth++; } static int sid_to_id(struct user_namespace *user_ns, struct smb_sid *psid, uint sidtype, struct smb_fattr *fattr) { int rc = -EINVAL; /* * If we have too many subauthorities, then something is really wrong. * Just return an error. */ if (unlikely(psid->num_subauth > SID_MAX_SUB_AUTHORITIES)) { pr_err("%s: %u subauthorities is too many!\n", __func__, psid->num_subauth); return -EIO; } if (sidtype == SIDOWNER) { kuid_t uid; uid_t id; id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]); if (id > 0) { uid = make_kuid(user_ns, id); if (uid_valid(uid) && kuid_has_mapping(user_ns, uid)) { fattr->cf_uid = uid; rc = 0; } } } else { kgid_t gid; gid_t id; id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]); if (id > 0) { gid = make_kgid(user_ns, id); if (gid_valid(gid) && kgid_has_mapping(user_ns, gid)) { fattr->cf_gid = gid; rc = 0; } } } return rc; } void posix_state_to_acl(struct posix_acl_state *state, struct posix_acl_entry *pace) { int i; pace->e_tag = ACL_USER_OBJ; pace->e_perm = state->owner.allow; for (i = 0; i < state->users->n; i++) { pace++; pace->e_tag = ACL_USER; pace->e_uid = state->users->aces[i].uid; pace->e_perm = state->users->aces[i].perms.allow; } pace++; pace->e_tag = ACL_GROUP_OBJ; pace->e_perm = state->group.allow; for (i = 0; i < state->groups->n; i++) { pace++; pace->e_tag = ACL_GROUP; pace->e_gid = state->groups->aces[i].gid; pace->e_perm = state->groups->aces[i].perms.allow; } if (state->users->n || state->groups->n) { pace++; pace->e_tag = ACL_MASK; pace->e_perm = state->mask.allow; } pace++; pace->e_tag = ACL_OTHER; pace->e_perm = state->other.allow; } int init_acl_state(struct posix_acl_state *state, int cnt) { int alloc; memset(state, 0, sizeof(struct posix_acl_state)); /* * In the worst case, each individual acl could be for a distinct * named user or group, but we don't know which, so we allocate * enough space for either: */ alloc = sizeof(struct posix_ace_state_array) + cnt * sizeof(struct posix_user_ace_state); state->users = kzalloc(alloc, GFP_KERNEL); if (!state->users) return -ENOMEM; state->groups = kzalloc(alloc, GFP_KERNEL); if (!state->groups) { kfree(state->users); return -ENOMEM; } return 0; } void free_acl_state(struct posix_acl_state *state) { kfree(state->users); kfree(state->groups); } static void parse_dacl(struct user_namespace *user_ns, struct smb_acl *pdacl, char *end_of_acl, struct smb_sid *pownersid, struct smb_sid *pgrpsid, struct smb_fattr *fattr) { int i, ret; int num_aces = 0; int acl_size; char *acl_base; struct smb_ace **ppace; struct posix_acl_entry *cf_pace, *cf_pdace; struct posix_acl_state acl_state, default_acl_state; umode_t mode = 0, acl_mode; bool owner_found = false, group_found = false, others_found = false; if (!pdacl) return; /* validate that we do not go past end of acl */ if (end_of_acl <= (char *)pdacl || end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) { pr_err("ACL too small to parse DACL\n"); return; } ksmbd_debug(SMB, "DACL revision %d size %d num aces %d\n", le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size), le32_to_cpu(pdacl->num_aces)); acl_base = (char *)pdacl; acl_size = sizeof(struct smb_acl); num_aces = le32_to_cpu(pdacl->num_aces); if (num_aces <= 0) return; if (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) return; ppace = kmalloc_array(num_aces, sizeof(struct smb_ace *), GFP_KERNEL); if (!ppace) return; ret = init_acl_state(&acl_state, num_aces); if (ret) return; ret = init_acl_state(&default_acl_state, num_aces); if (ret) { free_acl_state(&acl_state); return; } /* * reset rwx permissions for user/group/other. * Also, if num_aces is 0 i.e. DACL has no ACEs, * user/group/other have no permissions */ for (i = 0; i < num_aces; ++i) { ppace[i] = (struct smb_ace *)(acl_base + acl_size); acl_base = (char *)ppace[i]; acl_size = le16_to_cpu(ppace[i]->size); ppace[i]->access_req = smb_map_generic_desired_access(ppace[i]->access_req); if (!(compare_sids(&ppace[i]->sid, &sid_unix_NFS_mode))) { fattr->cf_mode = le32_to_cpu(ppace[i]->sid.sub_auth[2]); break; } else if (!compare_sids(&ppace[i]->sid, pownersid)) { acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req, ppace[i]->type); acl_mode &= 0700; if (!owner_found) { mode &= ~(0700); mode |= acl_mode; } owner_found = true; } else if (!compare_sids(&ppace[i]->sid, pgrpsid) || ppace[i]->sid.sub_auth[ppace[i]->sid.num_subauth - 1] == DOMAIN_USER_RID_LE) { acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req, ppace[i]->type); acl_mode &= 0070; if (!group_found) { mode &= ~(0070); mode |= acl_mode; } group_found = true; } else if (!compare_sids(&ppace[i]->sid, &sid_everyone)) { acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req, ppace[i]->type); acl_mode &= 0007; if (!others_found) { mode &= ~(0007); mode |= acl_mode; } others_found = true; } else if (!compare_sids(&ppace[i]->sid, &creator_owner)) { continue; } else if (!compare_sids(&ppace[i]->sid, &creator_group)) { continue; } else if (!compare_sids(&ppace[i]->sid, &sid_authusers)) { continue; } else { struct smb_fattr temp_fattr; acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req, ppace[i]->type); temp_fattr.cf_uid = INVALID_UID; ret = sid_to_id(user_ns, &ppace[i]->sid, SIDOWNER, &temp_fattr); if (ret || uid_eq(temp_fattr.cf_uid, INVALID_UID)) { pr_err("%s: Error %d mapping Owner SID to uid\n", __func__, ret); continue; } acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004; acl_state.users->aces[acl_state.users->n].uid = temp_fattr.cf_uid; acl_state.users->aces[acl_state.users->n++].perms.allow = ((acl_mode & 0700) >> 6) | 0004; default_acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004; default_acl_state.users->aces[default_acl_state.users->n].uid = temp_fattr.cf_uid; default_acl_state.users->aces[default_acl_state.users->n++].perms.allow = ((acl_mode & 0700) >> 6) | 0004; } } kfree(ppace); if (owner_found) { /* The owner must be set to at least read-only. */ acl_state.owner.allow = ((mode & 0700) >> 6) | 0004; acl_state.users->aces[acl_state.users->n].uid = fattr->cf_uid; acl_state.users->aces[acl_state.users->n++].perms.allow = ((mode & 0700) >> 6) | 0004; default_acl_state.owner.allow = ((mode & 0700) >> 6) | 0004; default_acl_state.users->aces[default_acl_state.users->n].uid = fattr->cf_uid; default_acl_state.users->aces[default_acl_state.users->n++].perms.allow = ((mode & 0700) >> 6) | 0004; } if (group_found) { acl_state.group.allow = (mode & 0070) >> 3; acl_state.groups->aces[acl_state.groups->n].gid = fattr->cf_gid; acl_state.groups->aces[acl_state.groups->n++].perms.allow = (mode & 0070) >> 3; default_acl_state.group.allow = (mode & 0070) >> 3; default_acl_state.groups->aces[default_acl_state.groups->n].gid = fattr->cf_gid; default_acl_state.groups->aces[default_acl_state.groups->n++].perms.allow = (mode & 0070) >> 3; } if (others_found) { fattr->cf_mode &= ~(0007); fattr->cf_mode |= mode & 0007; acl_state.other.allow = mode & 0007; default_acl_state.other.allow = mode & 0007; } if (acl_state.users->n || acl_state.groups->n) { acl_state.mask.allow = 0x07; if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { fattr->cf_acls = posix_acl_alloc(acl_state.users->n + acl_state.groups->n + 4, GFP_KERNEL); if (fattr->cf_acls) { cf_pace = fattr->cf_acls->a_entries; posix_state_to_acl(&acl_state, cf_pace); } } } if (default_acl_state.users->n || default_acl_state.groups->n) { default_acl_state.mask.allow = 0x07; if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { fattr->cf_dacls = posix_acl_alloc(default_acl_state.users->n + default_acl_state.groups->n + 4, GFP_KERNEL); if (fattr->cf_dacls) { cf_pdace = fattr->cf_dacls->a_entries; posix_state_to_acl(&default_acl_state, cf_pdace); } } } free_acl_state(&acl_state); free_acl_state(&default_acl_state); } static void set_posix_acl_entries_dacl(struct user_namespace *user_ns, struct smb_ace *pndace, struct smb_fattr *fattr, u32 *num_aces, u16 *size, u32 nt_aces_num) { struct posix_acl_entry *pace; struct smb_sid *sid; struct smb_ace *ntace; int i, j; if (!fattr->cf_acls) goto posix_default_acl; pace = fattr->cf_acls->a_entries; for (i = 0; i < fattr->cf_acls->a_count; i++, pace++) { int flags = 0; sid = kmalloc(sizeof(struct smb_sid), GFP_KERNEL); if (!sid) break; if (pace->e_tag == ACL_USER) { uid_t uid; unsigned int sid_type = SIDOWNER; uid = from_kuid(user_ns, pace->e_uid); 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); id_to_sid(gid, SIDUNIX_GROUP, sid); } else if (pace->e_tag == ACL_OTHER && !nt_aces_num) { smb_copy_sid(sid, &sid_everyone); } else { kfree(sid); continue; } ntace = pndace; for (j = 0; j < nt_aces_num; j++) { if (ntace->sid.sub_auth[ntace->sid.num_subauth - 1] == sid->sub_auth[sid->num_subauth - 1]) goto pass_same_sid; ntace = (struct smb_ace *)((char *)ntace + le16_to_cpu(ntace->size)); } if (S_ISDIR(fattr->cf_mode) && pace->e_tag == ACL_OTHER) flags = 0x03; ntace = (struct smb_ace *)((char *)pndace + *size); *size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, flags, pace->e_perm, 0777); (*num_aces)++; if (pace->e_tag == ACL_USER) ntace->access_req |= FILE_DELETE_LE | FILE_DELETE_CHILD_LE; if (S_ISDIR(fattr->cf_mode) && (pace->e_tag == ACL_USER || pace->e_tag == ACL_GROUP)) { ntace = (struct smb_ace *)((char *)pndace + *size); *size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, 0x03, pace->e_perm, 0777); (*num_aces)++; if (pace->e_tag == ACL_USER) ntace->access_req |= FILE_DELETE_LE | FILE_DELETE_CHILD_LE; } pass_same_sid: kfree(sid); } if (nt_aces_num) return; posix_default_acl: if (!fattr->cf_dacls) return; pace = fattr->cf_dacls->a_entries; for (i = 0; i < fattr->cf_dacls->a_count; i++, pace++) { sid = kmalloc(sizeof(struct smb_sid), GFP_KERNEL); if (!sid) break; if (pace->e_tag == ACL_USER) { uid_t uid; uid = from_kuid(user_ns, pace->e_uid); 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); id_to_sid(gid, SIDCREATOR_GROUP, sid); } else { kfree(sid); continue; } ntace = (struct smb_ace *)((char *)pndace + *size); *size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, 0x0b, pace->e_perm, 0777); (*num_aces)++; if (pace->e_tag == ACL_USER) ntace->access_req |= FILE_DELETE_LE | FILE_DELETE_CHILD_LE; kfree(sid); } } static void set_ntacl_dacl(struct user_namespace *user_ns, struct smb_acl *pndacl, struct smb_acl *nt_dacl, const struct smb_sid *pownersid, const struct smb_sid *pgrpsid, struct smb_fattr *fattr) { struct smb_ace *ntace, *pndace; int nt_num_aces = le32_to_cpu(nt_dacl->num_aces), num_aces = 0; unsigned short size = 0; int i; pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl)); if (nt_num_aces) { ntace = (struct smb_ace *)((char *)nt_dacl + sizeof(struct smb_acl)); for (i = 0; i < nt_num_aces; i++) { memcpy((char *)pndace + size, ntace, le16_to_cpu(ntace->size)); size += le16_to_cpu(ntace->size); ntace = (struct smb_ace *)((char *)ntace + le16_to_cpu(ntace->size)); num_aces++; } } set_posix_acl_entries_dacl(user_ns, pndace, fattr, &num_aces, &size, nt_num_aces); pndacl->num_aces = cpu_to_le32(num_aces); pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size); } static void set_mode_dacl(struct user_namespace *user_ns, struct smb_acl *pndacl, struct smb_fattr *fattr) { struct smb_ace *pace, *pndace; u32 num_aces = 0; u16 size = 0, ace_size = 0; uid_t uid; const struct smb_sid *sid; pace = pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl)); if (fattr->cf_acls) { set_posix_acl_entries_dacl(user_ns, pndace, fattr, &num_aces, &size, num_aces); goto out; } /* owner RID */ uid = from_kuid(&init_user_ns, fattr->cf_uid); if (uid) sid = &server_conf.domain_sid; else sid = &sid_unix_users; ace_size = fill_ace_for_sid(pace, sid, ACCESS_ALLOWED, 0, fattr->cf_mode, 0700); pace->sid.sub_auth[pace->sid.num_subauth++] = cpu_to_le32(uid); pace->size = cpu_to_le16(ace_size + 4); size += le16_to_cpu(pace->size); pace = (struct smb_ace *)((char *)pndace + size); /* Group RID */ ace_size = fill_ace_for_sid(pace, &sid_unix_groups, ACCESS_ALLOWED, 0, fattr->cf_mode, 0070); pace->sid.sub_auth[pace->sid.num_subauth++] = cpu_to_le32(from_kgid(&init_user_ns, fattr->cf_gid)); pace->size = cpu_to_le16(ace_size + 4); size += le16_to_cpu(pace->size); pace = (struct smb_ace *)((char *)pndace + size); num_aces = 3; if (S_ISDIR(fattr->cf_mode)) { pace = (struct smb_ace *)((char *)pndace + size); /* creator owner */ size += fill_ace_for_sid(pace, &creator_owner, ACCESS_ALLOWED, 0x0b, fattr->cf_mode, 0700); pace = (struct smb_ace *)((char *)pndace + size); /* creator group */ size += fill_ace_for_sid(pace, &creator_group, ACCESS_ALLOWED, 0x0b, fattr->cf_mode, 0070); pace = (struct smb_ace *)((char *)pndace + size); num_aces = 5; } /* other */ size += fill_ace_for_sid(pace, &sid_everyone, ACCESS_ALLOWED, 0, fattr->cf_mode, 0007); out: pndacl->num_aces = cpu_to_le32(num_aces); pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size); } static int parse_sid(struct smb_sid *psid, char *end_of_acl) { /* * validate that we do not go past end of ACL - sid must be at least 8 * bytes long (assuming no sub-auths - e.g. the null SID */ if (end_of_acl < (char *)psid + 8) { pr_err("ACL too small to parse SID %p\n", psid); return -EINVAL; } return 0; } /* Convert CIFS ACL to POSIX form */ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, int acl_len, struct smb_fattr *fattr) { int rc = 0; struct smb_sid *owner_sid_ptr, *group_sid_ptr; struct smb_acl *dacl_ptr; /* no need for SACL ptr */ char *end_of_acl = ((char *)pntsd) + acl_len; __u32 dacloffset; int pntsd_type; if (!pntsd) return -EIO; owner_sid_ptr = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->osidoffset)); group_sid_ptr = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->gsidoffset)); dacloffset = le32_to_cpu(pntsd->dacloffset); dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); ksmbd_debug(SMB, "revision %d type 0x%x ooffset 0x%x goffset 0x%x sacloffset 0x%x dacloffset 0x%x\n", pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset), le32_to_cpu(pntsd->gsidoffset), le32_to_cpu(pntsd->sacloffset), dacloffset); pntsd_type = le16_to_cpu(pntsd->type); if (!(pntsd_type & DACL_PRESENT)) { ksmbd_debug(SMB, "DACL_PRESENT in DACL type is not set\n"); return rc; } pntsd->type = cpu_to_le16(DACL_PRESENT); if (pntsd->osidoffset) { rc = parse_sid(owner_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d parsing Owner SID\n", __func__, rc); return rc; } rc = sid_to_id(user_ns, owner_sid_ptr, SIDOWNER, fattr); if (rc) { pr_err("%s: Error %d mapping Owner SID to uid\n", __func__, rc); owner_sid_ptr = NULL; } } if (pntsd->gsidoffset) { rc = parse_sid(group_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d mapping Owner SID to gid\n", __func__, rc); return rc; } rc = sid_to_id(user_ns, group_sid_ptr, SIDUNIX_GROUP, fattr); if (rc) { pr_err("%s: Error %d mapping Group SID to gid\n", __func__, rc); group_sid_ptr = NULL; } } if ((pntsd_type & (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ)) == (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ)) pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED); if (pntsd_type & DACL_PROTECTED) pntsd->type |= cpu_to_le16(DACL_PROTECTED); if (dacloffset) { parse_dacl(user_ns, dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr, fattr); } return 0; } /* Convert permission bits from mode to equivalent CIFS ACL */ int build_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd, int addition_info, __u32 *secdesclen, struct smb_fattr *fattr) { int rc = 0; __u32 offset; struct smb_sid *owner_sid_ptr, *group_sid_ptr; struct smb_sid *nowner_sid_ptr, *ngroup_sid_ptr; struct smb_acl *dacl_ptr = NULL; /* no need for SACL ptr */ uid_t uid; gid_t gid; unsigned int sid_type = SIDOWNER; nowner_sid_ptr = kmalloc(sizeof(struct smb_sid), GFP_KERNEL); if (!nowner_sid_ptr) return -ENOMEM; uid = from_kuid(&init_user_ns, fattr->cf_uid); if (!uid) sid_type = SIDUNIX_USER; id_to_sid(uid, sid_type, nowner_sid_ptr); ngroup_sid_ptr = kmalloc(sizeof(struct smb_sid), GFP_KERNEL); if (!ngroup_sid_ptr) { kfree(nowner_sid_ptr); return -ENOMEM; } gid = from_kgid(&init_user_ns, fattr->cf_gid); id_to_sid(gid, SIDUNIX_GROUP, ngroup_sid_ptr); offset = sizeof(struct smb_ntsd); pntsd->sacloffset = 0; pntsd->revision = cpu_to_le16(1); pntsd->type = cpu_to_le16(SELF_RELATIVE); if (ppntsd) pntsd->type |= ppntsd->type; if (addition_info & OWNER_SECINFO) { pntsd->osidoffset = cpu_to_le32(offset); owner_sid_ptr = (struct smb_sid *)((char *)pntsd + offset); smb_copy_sid(owner_sid_ptr, nowner_sid_ptr); offset += 1 + 1 + 6 + (nowner_sid_ptr->num_subauth * 4); } if (addition_info & GROUP_SECINFO) { pntsd->gsidoffset = cpu_to_le32(offset); group_sid_ptr = (struct smb_sid *)((char *)pntsd + offset); smb_copy_sid(group_sid_ptr, ngroup_sid_ptr); offset += 1 + 1 + 6 + (ngroup_sid_ptr->num_subauth * 4); } if (addition_info & DACL_SECINFO) { pntsd->type |= cpu_to_le16(DACL_PRESENT); dacl_ptr = (struct smb_acl *)((char *)pntsd + offset); dacl_ptr->revision = cpu_to_le16(2); dacl_ptr->size = cpu_to_le16(sizeof(struct smb_acl)); dacl_ptr->num_aces = 0; if (!ppntsd) { set_mode_dacl(user_ns, dacl_ptr, fattr); } else if (!ppntsd->dacloffset) { goto out; } else { struct smb_acl *ppdacl_ptr; ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + le32_to_cpu(ppntsd->dacloffset)); set_ntacl_dacl(user_ns, dacl_ptr, ppdacl_ptr, nowner_sid_ptr, ngroup_sid_ptr, fattr); } pntsd->dacloffset = cpu_to_le32(offset); offset += le16_to_cpu(dacl_ptr->size); } out: kfree(nowner_sid_ptr); kfree(ngroup_sid_ptr); *secdesclen = offset; return rc; } static void smb_set_ace(struct smb_ace *ace, const struct smb_sid *sid, u8 type, u8 flags, __le32 access_req) { ace->type = type; ace->flags = flags; ace->access_req = access_req; smb_copy_sid(&ace->sid, sid); ace->size = cpu_to_le16(1 + 1 + 2 + 4 + 1 + 1 + 6 + (sid->num_subauth * 4)); } int smb_inherit_dacl(struct ksmbd_conn *conn, struct path *path, unsigned int uid, unsigned int gid) { const struct smb_sid *psid, *creator = NULL; struct smb_ace *parent_aces, *aces; struct smb_acl *parent_pdacl; struct smb_ntsd *parent_pntsd = NULL; struct smb_sid owner_sid, group_sid; struct dentry *parent = path->dentry->d_parent; struct user_namespace *user_ns = mnt_user_ns(path->mnt); int inherited_flags = 0, flags = 0, i, ace_cnt = 0, nt_size = 0; int rc = 0, num_aces, dacloffset, pntsd_type, acl_len; char *aces_base; bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode); acl_len = ksmbd_vfs_get_sd_xattr(conn, user_ns, parent, &parent_pntsd); if (acl_len <= 0) return -ENOENT; dacloffset = le32_to_cpu(parent_pntsd->dacloffset); if (!dacloffset) { rc = -EINVAL; goto free_parent_pntsd; } parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset); num_aces = le32_to_cpu(parent_pdacl->num_aces); pntsd_type = le16_to_cpu(parent_pntsd->type); aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2, GFP_KERNEL); if (!aces_base) { rc = -ENOMEM; goto free_parent_pntsd; } aces = (struct smb_ace *)aces_base; parent_aces = (struct smb_ace *)((char *)parent_pdacl + sizeof(struct smb_acl)); if (pntsd_type & DACL_AUTO_INHERITED) inherited_flags = INHERITED_ACE; for (i = 0; i < num_aces; i++) { flags = parent_aces->flags; if (!smb_inherit_flags(flags, is_dir)) goto pass; if (is_dir) { flags &= ~(INHERIT_ONLY_ACE | INHERITED_ACE); if (!(flags & CONTAINER_INHERIT_ACE)) flags |= INHERIT_ONLY_ACE; if (flags & NO_PROPAGATE_INHERIT_ACE) flags = 0; } else { flags = 0; } if (!compare_sids(&creator_owner, &parent_aces->sid)) { creator = &creator_owner; id_to_sid(uid, SIDOWNER, &owner_sid); psid = &owner_sid; } else if (!compare_sids(&creator_group, &parent_aces->sid)) { creator = &creator_group; id_to_sid(gid, SIDUNIX_GROUP, &group_sid); psid = &group_sid; } else { creator = NULL; psid = &parent_aces->sid; } if (is_dir && creator && flags & CONTAINER_INHERIT_ACE) { smb_set_ace(aces, psid, parent_aces->type, inherited_flags, parent_aces->access_req); nt_size += le16_to_cpu(aces->size); ace_cnt++; aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size)); flags |= INHERIT_ONLY_ACE; psid = creator; } else if (is_dir && !(parent_aces->flags & NO_PROPAGATE_INHERIT_ACE)) { psid = &parent_aces->sid; } smb_set_ace(aces, psid, parent_aces->type, flags | inherited_flags, parent_aces->access_req); nt_size += le16_to_cpu(aces->size); aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size)); ace_cnt++; pass: parent_aces = (struct smb_ace *)((char *)parent_aces + le16_to_cpu(parent_aces->size)); } if (nt_size > 0) { struct smb_ntsd *pntsd; struct smb_acl *pdacl; struct smb_sid *powner_sid = NULL, *pgroup_sid = NULL; int powner_sid_size = 0, pgroup_sid_size = 0, pntsd_size; if (parent_pntsd->osidoffset) { powner_sid = (struct smb_sid *)((char *)parent_pntsd + le32_to_cpu(parent_pntsd->osidoffset)); powner_sid_size = 1 + 1 + 6 + (powner_sid->num_subauth * 4); } if (parent_pntsd->gsidoffset) { pgroup_sid = (struct smb_sid *)((char *)parent_pntsd + le32_to_cpu(parent_pntsd->gsidoffset)); pgroup_sid_size = 1 + 1 + 6 + (pgroup_sid->num_subauth * 4); } pntsd = kzalloc(sizeof(struct smb_ntsd) + powner_sid_size + pgroup_sid_size + sizeof(struct smb_acl) + nt_size, GFP_KERNEL); if (!pntsd) { rc = -ENOMEM; goto free_aces_base; } pntsd->revision = cpu_to_le16(1); pntsd->type = cpu_to_le16(SELF_RELATIVE | DACL_PRESENT); if (le16_to_cpu(parent_pntsd->type) & DACL_AUTO_INHERITED) pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED); pntsd_size = sizeof(struct smb_ntsd); pntsd->osidoffset = parent_pntsd->osidoffset; pntsd->gsidoffset = parent_pntsd->gsidoffset; pntsd->dacloffset = parent_pntsd->dacloffset; if (pntsd->osidoffset) { struct smb_sid *owner_sid = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->osidoffset)); memcpy(owner_sid, powner_sid, powner_sid_size); pntsd_size += powner_sid_size; } if (pntsd->gsidoffset) { struct smb_sid *group_sid = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->gsidoffset)); memcpy(group_sid, pgroup_sid, pgroup_sid_size); pntsd_size += pgroup_sid_size; } if (pntsd->dacloffset) { struct smb_ace *pace; pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset)); pdacl->revision = cpu_to_le16(2); pdacl->size = cpu_to_le16(sizeof(struct smb_acl) + nt_size); pdacl->num_aces = cpu_to_le32(ace_cnt); pace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); memcpy(pace, aces_base, nt_size); pntsd_size += sizeof(struct smb_acl) + nt_size; } ksmbd_vfs_set_sd_xattr(conn, user_ns, path->dentry, pntsd, pntsd_size); kfree(pntsd); } free_aces_base: kfree(aces_base); free_parent_pntsd: kfree(parent_pntsd); return rc; } bool smb_inherit_flags(int flags, bool is_dir) { if (!is_dir) return (flags & OBJECT_INHERIT_ACE) != 0; if (flags & OBJECT_INHERIT_ACE && !(flags & NO_PROPAGATE_INHERIT_ACE)) return true; if (flags & CONTAINER_INHERIT_ACE) return true; return false; } int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path, __le32 *pdaccess, int uid) { struct user_namespace *user_ns = mnt_user_ns(path->mnt); struct smb_ntsd *pntsd = NULL; struct smb_acl *pdacl; struct posix_acl *posix_acls; int rc = 0, acl_size; struct smb_sid sid; int granted = le32_to_cpu(*pdaccess & ~FILE_MAXIMAL_ACCESS_LE); struct smb_ace *ace; int i, found = 0; unsigned int access_bits = 0; struct smb_ace *others_ace = NULL; struct posix_acl_entry *pa_entry; unsigned int sid_type = SIDOWNER; char *end_of_acl; ksmbd_debug(SMB, "check permission using windows acl\n"); acl_size = ksmbd_vfs_get_sd_xattr(conn, user_ns, path->dentry, &pntsd); if (acl_size <= 0 || !pntsd || !pntsd->dacloffset) { kfree(pntsd); return 0; } pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset)); end_of_acl = ((char *)pntsd) + acl_size; if (end_of_acl <= (char *)pdacl) { kfree(pntsd); return 0; } if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size) || le16_to_cpu(pdacl->size) < sizeof(struct smb_acl)) { kfree(pntsd); return 0; } if (!pdacl->num_aces) { if (!(le16_to_cpu(pdacl->size) - sizeof(struct smb_acl)) && *pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) { rc = -EACCES; goto err_out; } kfree(pntsd); return 0; } if (*pdaccess & FILE_MAXIMAL_ACCESS_LE) { granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES | DELETE; ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) { granted |= le32_to_cpu(ace->access_req); ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size)); if (end_of_acl < (char *)ace) goto err_out; } if (!pdacl->num_aces) granted = GENERIC_ALL_FLAGS; } if (!uid) sid_type = SIDUNIX_USER; id_to_sid(uid, sid_type, &sid); ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) { if (!compare_sids(&sid, &ace->sid) || !compare_sids(&sid_unix_NFS_mode, &ace->sid)) { found = 1; break; } if (!compare_sids(&sid_everyone, &ace->sid)) others_ace = ace; ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size)); if (end_of_acl < (char *)ace) goto err_out; } if (*pdaccess & FILE_MAXIMAL_ACCESS_LE && found) { granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES | DELETE; granted |= le32_to_cpu(ace->access_req); if (!pdacl->num_aces) granted = GENERIC_ALL_FLAGS; } if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { posix_acls = get_acl(d_inode(path->dentry), ACL_TYPE_ACCESS); if (posix_acls && !found) { unsigned int id = -1; 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); else if (pa_entry->e_tag == ACL_GROUP) id = from_kgid(user_ns, pa_entry->e_gid); else continue; if (id == uid) { mode_to_access_flags(pa_entry->e_perm, 0777, &access_bits); if (!access_bits) access_bits = SET_MINIMUM_RIGHTS; goto check_access_bits; } } } if (posix_acls) posix_acl_release(posix_acls); } if (!found) { if (others_ace) { ace = others_ace; } else { ksmbd_debug(SMB, "Can't find corresponding sid\n"); rc = -EACCES; goto err_out; } } switch (ace->type) { case ACCESS_ALLOWED_ACE_TYPE: access_bits = le32_to_cpu(ace->access_req); break; case ACCESS_DENIED_ACE_TYPE: case ACCESS_DENIED_CALLBACK_ACE_TYPE: access_bits = le32_to_cpu(~ace->access_req); break; } check_access_bits: if (granted & ~(access_bits | FILE_READ_ATTRIBUTES | READ_CONTROL | WRITE_DAC | DELETE)) { ksmbd_debug(SMB, "Access denied with winACL, granted : %x, access_req : %x\n", granted, le32_to_cpu(ace->access_req)); rc = -EACCES; goto err_out; } *pdaccess = cpu_to_le32(granted); err_out: kfree(pntsd); return rc; } int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon, struct path *path, struct smb_ntsd *pntsd, int ntsd_len, bool type_check) { int rc; struct smb_fattr fattr = {{0}}; struct inode *inode = d_inode(path->dentry); struct user_namespace *user_ns = mnt_user_ns(path->mnt); struct iattr newattrs; fattr.cf_uid = INVALID_UID; fattr.cf_gid = INVALID_GID; fattr.cf_mode = inode->i_mode; rc = parse_sec_desc(user_ns, pntsd, ntsd_len, &fattr); if (rc) goto out; newattrs.ia_valid = ATTR_CTIME; if (!uid_eq(fattr.cf_uid, INVALID_UID)) { newattrs.ia_valid |= ATTR_UID; newattrs.ia_uid = fattr.cf_uid; } if (!gid_eq(fattr.cf_gid, INVALID_GID)) { newattrs.ia_valid |= ATTR_GID; newattrs.ia_gid = fattr.cf_gid; } newattrs.ia_valid |= ATTR_MODE; newattrs.ia_mode = (inode->i_mode & ~0777) | (fattr.cf_mode & 0777); inode_lock(inode); rc = notify_change(user_ns, path->dentry, &newattrs, NULL); inode_unlock(inode); if (rc) goto out; ksmbd_vfs_remove_acl_xattrs(user_ns, path->dentry); /* Update posix acls */ if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && fattr.cf_dacls) { rc = set_posix_acl(user_ns, inode, ACL_TYPE_ACCESS, fattr.cf_acls); if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) rc = set_posix_acl(user_ns, inode, ACL_TYPE_DEFAULT, fattr.cf_dacls); } /* Check it only calling from SD BUFFER context */ if (type_check && !(le16_to_cpu(pntsd->type) & DACL_PRESENT)) goto out; if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) { /* Update WinACL in xattr */ ksmbd_vfs_remove_sd_xattrs(user_ns, path->dentry); ksmbd_vfs_set_sd_xattr(conn, user_ns, path->dentry, pntsd, ntsd_len); } out: posix_acl_release(fattr.cf_acls); posix_acl_release(fattr.cf_dacls); mark_inode_dirty(inode); return rc; } void ksmbd_init_domain(u32 *sub_auth) { int i; memcpy(&server_conf.domain_sid, &domain, sizeof(struct smb_sid)); for (i = 0; i < 3; ++i) server_conf.domain_sid.sub_auth[i + 1] = cpu_to_le32(sub_auth[i]); }