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-rw-r--r--fs/smb/server/smbacl.c1436
1 files changed, 1436 insertions, 0 deletions
diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c
new file mode 100644
index 000000000000..b05ff9b146b5
--- /dev/null
+++ b/fs/smb/server/smbacl.c
@@ -0,0 +1,1436 @@
+// 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 <linkinjeon@kernel.org>
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/mnt_idmapping.h>
+
+#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]);
+		uid = KUIDT_INIT(id);
+		uid = from_vfsuid(user_ns, &init_user_ns, VFSUIDT_INIT(uid));
+		if (uid_valid(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]);
+		gid = KGIDT_INIT(id);
+		gid = from_vfsgid(user_ns, &init_user_ns, VFSGIDT_INIT(gid));
+		if (gid_valid(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;
+	unsigned 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 + sizeof(struct smb_acl) ||
+	    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) {
+		if (end_of_acl - acl_base < acl_size)
+			break;
+
+		ppace[i] = (struct smb_ace *)(acl_base + acl_size);
+		acl_base = (char *)ppace[i];
+		acl_size = offsetof(struct smb_ace, sid) +
+			offsetof(struct smb_sid, sub_auth);
+
+		if (end_of_acl - acl_base < acl_size ||
+		    ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
+		    (end_of_acl - acl_base <
+		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) ||
+		    (le16_to_cpu(ppace[i]->size) <
+		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth))
+			break;
+
+		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 = 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 = 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);
+		} 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 = 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 = posix_acl_gid_translate(user_ns, pace);
+			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,
+			   unsigned int aces_size,
+			   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++) {
+			unsigned short nt_ace_size;
+
+			if (offsetof(struct smb_ace, access_req) > aces_size)
+				break;
+
+			nt_ace_size = le16_to_cpu(ntace->size);
+			if (nt_ace_size > aces_size)
+				break;
+
+			memcpy((char *)pndace + size, ntace, nt_ace_size);
+			size += nt_ace_size;
+			aces_size -= nt_ace_size;
+			ntace = (struct smb_ace *)((char *)ntace + nt_ace_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;
+
+	if (acl_len < sizeof(struct smb_ntsd))
+		return -EINVAL;
+
+	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 ppntsd_size, 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 {
+			struct smb_acl *ppdacl_ptr;
+			unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset);
+			int ppdacl_size, ntacl_size = ppntsd_size - dacl_offset;
+
+			if (!dacl_offset ||
+			    (dacl_offset + sizeof(struct smb_acl) > ppntsd_size))
+				goto out;
+
+			ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + dacl_offset);
+			ppdacl_size = le16_to_cpu(ppdacl_ptr->size);
+			if (ppdacl_size > ntacl_size ||
+			    ppdacl_size < sizeof(struct smb_acl))
+				goto out;
+
+			set_ntacl_dacl(user_ns, dacl_ptr, ppdacl_ptr,
+				       ntacl_size - sizeof(struct smb_acl),
+				       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,
+		     const 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, pdacl_size;
+	int rc = 0, num_aces, dacloffset, pntsd_type, pntsd_size, acl_len, aces_size;
+	char *aces_base;
+	bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode);
+
+	pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
+					    parent, &parent_pntsd);
+	if (pntsd_size <= 0)
+		return -ENOENT;
+	dacloffset = le32_to_cpu(parent_pntsd->dacloffset);
+	if (!dacloffset || (dacloffset + sizeof(struct smb_acl) > pntsd_size)) {
+		rc = -EINVAL;
+		goto free_parent_pntsd;
+	}
+
+	parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset);
+	acl_len = pntsd_size - dacloffset;
+	num_aces = le32_to_cpu(parent_pdacl->num_aces);
+	pntsd_type = le16_to_cpu(parent_pntsd->type);
+	pdacl_size = le16_to_cpu(parent_pdacl->size);
+
+	if (pdacl_size > acl_len || pdacl_size < sizeof(struct smb_acl)) {
+		rc = -EINVAL;
+		goto free_parent_pntsd;
+	}
+
+	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));
+	aces_size = acl_len - sizeof(struct smb_acl);
+
+	if (pntsd_type & DACL_AUTO_INHERITED)
+		inherited_flags = INHERITED_ACE;
+
+	for (i = 0; i < num_aces; i++) {
+		int pace_size;
+
+		if (offsetof(struct smb_ace, access_req) > aces_size)
+			break;
+
+		pace_size = le16_to_cpu(parent_aces->size);
+		if (pace_size > aces_size)
+			break;
+
+		aces_size -= pace_size;
+
+		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 + pace_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, const 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, pntsd_size, acl_size, aces_size, pdacl_size, dacl_offset;
+	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;
+	unsigned short ace_size;
+
+	ksmbd_debug(SMB, "check permission using windows acl\n");
+	pntsd_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
+					    path->dentry, &pntsd);
+	if (pntsd_size <= 0 || !pntsd)
+		goto err_out;
+
+	dacl_offset = le32_to_cpu(pntsd->dacloffset);
+	if (!dacl_offset ||
+	    (dacl_offset + sizeof(struct smb_acl) > pntsd_size))
+		goto err_out;
+
+	pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
+	acl_size = pntsd_size - dacl_offset;
+	pdacl_size = le16_to_cpu(pdacl->size);
+
+	if (pdacl_size > acl_size || pdacl_size < sizeof(struct smb_acl))
+		goto err_out;
+
+	if (!pdacl->num_aces) {
+		if (!(pdacl_size - sizeof(struct smb_acl)) &&
+		    *pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) {
+			rc = -EACCES;
+			goto err_out;
+		}
+		goto err_out;
+	}
+
+	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));
+		aces_size = acl_size - sizeof(struct smb_acl);
+		for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) {
+			if (offsetof(struct smb_ace, access_req) > aces_size)
+				break;
+			ace_size = le16_to_cpu(ace->size);
+			if (ace_size > aces_size)
+				break;
+			aces_size -= ace_size;
+			granted |= le32_to_cpu(ace->access_req);
+			ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
+		}
+
+		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));
+	aces_size = acl_size - sizeof(struct smb_acl);
+	for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) {
+		if (offsetof(struct smb_ace, access_req) > aces_size)
+			break;
+		ace_size = le16_to_cpu(ace->size);
+		if (ace_size > aces_size)
+			break;
+		aces_size -= ace_size;
+
+		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 (*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 = posix_acl_uid_translate(user_ns, pa_entry);
+				else if (pa_entry->e_tag == ACL_GROUP)
+					id = posix_acl_gid_translate(user_ns, pa_entry);
+				else
+					continue;
+
+				if (id == uid) {
+					mode_to_access_flags(pa_entry->e_perm,
+							     0777,
+							     &access_bits);
+					if (!access_bits)
+						access_bits =
+							SET_MINIMUM_RIGHTS;
+					posix_acl_release(posix_acls);
+					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,
+		 const 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);
+
+	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 (rc < 0)
+			ksmbd_debug(SMB,
+				    "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
+				    rc);
+		if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) {
+			rc = set_posix_acl(user_ns, inode,
+					   ACL_TYPE_DEFAULT, fattr.cf_dacls);
+			if (rc)
+				ksmbd_debug(SMB,
+					    "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
+					    rc);
+		}
+	}
+
+	inode_lock(inode);
+	rc = notify_change(user_ns, path->dentry, &newattrs, NULL);
+	inode_unlock(inode);
+	if (rc)
+		goto out;
+
+	/* 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]);
+}