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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/smb/client/cifsacl.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/smb/client/cifsacl.c')
-rw-r--r--fs/smb/client/cifsacl.c1672
1 files changed, 1672 insertions, 0 deletions
diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c
new file mode 100644
index 000000000..a6c7566a0
--- /dev/null
+++ b/fs/smb/client/cifsacl.c
@@ -0,0 +1,1672 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ *
+ * Copyright (C) International Business Machines Corp., 2007,2008
+ * Author(s): Steve French (sfrench@us.ibm.com)
+ *
+ * Contains the routines for mapping CIFS/NTFS ACLs
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/keyctl.h>
+#include <linux/key-type.h>
+#include <keys/user-type.h>
+#include "cifspdu.h"
+#include "cifsglob.h"
+#include "cifsacl.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+#include "fs_context.h"
+
+/* security id for everyone/world system group */
+static const struct cifs_sid sid_everyone = {
+ 1, 1, {0, 0, 0, 0, 0, 1}, {0} };
+/* security id for Authenticated Users system group */
+static const struct cifs_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 cifs_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 cifs_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 https://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 cifs_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 cifs_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 cifs_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} };
+
+static const struct cred *root_cred;
+
+static int
+cifs_idmap_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
+{
+ char *payload;
+
+ /*
+ * If the payload is less than or equal to the size of a pointer, then
+ * an allocation here is wasteful. Just copy the data directly to the
+ * payload.value union member instead.
+ *
+ * With this however, you must check the datalen before trying to
+ * dereference payload.data!
+ */
+ if (prep->datalen <= sizeof(key->payload)) {
+ key->payload.data[0] = NULL;
+ memcpy(&key->payload, prep->data, prep->datalen);
+ } else {
+ payload = kmemdup(prep->data, prep->datalen, GFP_KERNEL);
+ if (!payload)
+ return -ENOMEM;
+ key->payload.data[0] = payload;
+ }
+
+ key->datalen = prep->datalen;
+ return 0;
+}
+
+static inline void
+cifs_idmap_key_destroy(struct key *key)
+{
+ if (key->datalen > sizeof(key->payload))
+ kfree(key->payload.data[0]);
+}
+
+static struct key_type cifs_idmap_key_type = {
+ .name = "cifs.idmap",
+ .instantiate = cifs_idmap_key_instantiate,
+ .destroy = cifs_idmap_key_destroy,
+ .describe = user_describe,
+};
+
+static char *
+sid_to_key_str(struct cifs_sid *sidptr, unsigned int type)
+{
+ int i, len;
+ unsigned int saval;
+ char *sidstr, *strptr;
+ unsigned long long id_auth_val;
+
+ /* 3 bytes for prefix */
+ sidstr = kmalloc(3 + SID_STRING_BASE_SIZE +
+ (SID_STRING_SUBAUTH_SIZE * sidptr->num_subauth),
+ GFP_KERNEL);
+ if (!sidstr)
+ return sidstr;
+
+ strptr = sidstr;
+ len = sprintf(strptr, "%cs:S-%hhu", type == SIDOWNER ? 'o' : 'g',
+ sidptr->revision);
+ strptr += len;
+
+ /* The authority field is a single 48-bit number */
+ id_auth_val = (unsigned long long)sidptr->authority[5];
+ id_auth_val |= (unsigned long long)sidptr->authority[4] << 8;
+ id_auth_val |= (unsigned long long)sidptr->authority[3] << 16;
+ id_auth_val |= (unsigned long long)sidptr->authority[2] << 24;
+ id_auth_val |= (unsigned long long)sidptr->authority[1] << 32;
+ id_auth_val |= (unsigned long long)sidptr->authority[0] << 48;
+
+ /*
+ * MS-DTYP states that if the authority is >= 2^32, then it should be
+ * expressed as a hex value.
+ */
+ if (id_auth_val <= UINT_MAX)
+ len = sprintf(strptr, "-%llu", id_auth_val);
+ else
+ len = sprintf(strptr, "-0x%llx", id_auth_val);
+
+ strptr += len;
+
+ for (i = 0; i < sidptr->num_subauth; ++i) {
+ saval = le32_to_cpu(sidptr->sub_auth[i]);
+ len = sprintf(strptr, "-%u", saval);
+ strptr += len;
+ }
+
+ return sidstr;
+}
+
+/*
+ * 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.
+ */
+static int
+compare_sids(const struct cifs_sid *ctsid, const struct cifs_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 bool
+is_well_known_sid(const struct cifs_sid *psid, uint32_t *puid, bool is_group)
+{
+ int i;
+ int num_subauth;
+ const struct cifs_sid *pwell_known_sid;
+
+ if (!psid || (puid == NULL))
+ return false;
+
+ num_subauth = psid->num_subauth;
+
+ /* check if Mac (or Windows NFS) vs. Samba format for Unix owner SID */
+ if (num_subauth == 2) {
+ if (is_group)
+ pwell_known_sid = &sid_unix_groups;
+ else
+ pwell_known_sid = &sid_unix_users;
+ } else if (num_subauth == 3) {
+ if (is_group)
+ pwell_known_sid = &sid_unix_NFS_groups;
+ else
+ pwell_known_sid = &sid_unix_NFS_users;
+ } else
+ return false;
+
+ /* compare the revision */
+ if (psid->revision != pwell_known_sid->revision)
+ return false;
+
+ /* compare all of the six auth values */
+ for (i = 0; i < NUM_AUTHS; ++i) {
+ if (psid->authority[i] != pwell_known_sid->authority[i]) {
+ cifs_dbg(FYI, "auth %d did not match\n", i);
+ return false;
+ }
+ }
+
+ if (num_subauth == 2) {
+ if (psid->sub_auth[0] != pwell_known_sid->sub_auth[0])
+ return false;
+
+ *puid = le32_to_cpu(psid->sub_auth[1]);
+ } else /* 3 subauths, ie Windows/Mac style */ {
+ *puid = le32_to_cpu(psid->sub_auth[0]);
+ if ((psid->sub_auth[0] != pwell_known_sid->sub_auth[0]) ||
+ (psid->sub_auth[1] != pwell_known_sid->sub_auth[1]))
+ return false;
+
+ *puid = le32_to_cpu(psid->sub_auth[2]);
+ }
+
+ cifs_dbg(FYI, "Unix UID %d returned from SID\n", *puid);
+ return true; /* well known sid found, uid returned */
+}
+
+static __u16
+cifs_copy_sid(struct cifs_sid *dst, const struct cifs_sid *src)
+{
+ int i;
+ __u16 size = 1 + 1 + 6;
+
+ 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];
+ size += (dst->num_subauth * 4);
+
+ return size;
+}
+
+static int
+id_to_sid(unsigned int cid, uint sidtype, struct cifs_sid *ssid)
+{
+ int rc;
+ struct key *sidkey;
+ struct cifs_sid *ksid;
+ unsigned int ksid_size;
+ char desc[3 + 10 + 1]; /* 3 byte prefix + 10 bytes for value + NULL */
+ const struct cred *saved_cred;
+
+ rc = snprintf(desc, sizeof(desc), "%ci:%u",
+ sidtype == SIDOWNER ? 'o' : 'g', cid);
+ if (rc >= sizeof(desc))
+ return -EINVAL;
+
+ rc = 0;
+ saved_cred = override_creds(root_cred);
+ sidkey = request_key(&cifs_idmap_key_type, desc, "");
+ if (IS_ERR(sidkey)) {
+ rc = -EINVAL;
+ cifs_dbg(FYI, "%s: Can't map %cid %u to a SID\n",
+ __func__, sidtype == SIDOWNER ? 'u' : 'g', cid);
+ goto out_revert_creds;
+ } else if (sidkey->datalen < CIFS_SID_BASE_SIZE) {
+ rc = -EIO;
+ cifs_dbg(FYI, "%s: Downcall contained malformed key (datalen=%hu)\n",
+ __func__, sidkey->datalen);
+ goto invalidate_key;
+ }
+
+ /*
+ * A sid is usually too large to be embedded in payload.value, but if
+ * there are no subauthorities and the host has 8-byte pointers, then
+ * it could be.
+ */
+ ksid = sidkey->datalen <= sizeof(sidkey->payload) ?
+ (struct cifs_sid *)&sidkey->payload :
+ (struct cifs_sid *)sidkey->payload.data[0];
+
+ ksid_size = CIFS_SID_BASE_SIZE + (ksid->num_subauth * sizeof(__le32));
+ if (ksid_size > sidkey->datalen) {
+ rc = -EIO;
+ cifs_dbg(FYI, "%s: Downcall contained malformed key (datalen=%hu, ksid_size=%u)\n",
+ __func__, sidkey->datalen, ksid_size);
+ goto invalidate_key;
+ }
+
+ cifs_copy_sid(ssid, ksid);
+out_key_put:
+ key_put(sidkey);
+out_revert_creds:
+ revert_creds(saved_cred);
+ return rc;
+
+invalidate_key:
+ key_invalidate(sidkey);
+ goto out_key_put;
+}
+
+int
+sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
+ struct cifs_fattr *fattr, uint sidtype)
+{
+ int rc = 0;
+ struct key *sidkey;
+ char *sidstr;
+ const struct cred *saved_cred;
+ kuid_t fuid = cifs_sb->ctx->linux_uid;
+ kgid_t fgid = cifs_sb->ctx->linux_gid;
+
+ /*
+ * If we have too many subauthorities, then something is really wrong.
+ * Just return an error.
+ */
+ if (unlikely(psid->num_subauth > SID_MAX_SUB_AUTHORITIES)) {
+ cifs_dbg(FYI, "%s: %u subauthorities is too many!\n",
+ __func__, psid->num_subauth);
+ return -EIO;
+ }
+
+ if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UID_FROM_ACL) ||
+ (cifs_sb_master_tcon(cifs_sb)->posix_extensions)) {
+ uint32_t unix_id;
+ bool is_group;
+
+ if (sidtype != SIDOWNER)
+ is_group = true;
+ else
+ is_group = false;
+
+ if (is_well_known_sid(psid, &unix_id, is_group) == false)
+ goto try_upcall_to_get_id;
+
+ if (is_group) {
+ kgid_t gid;
+ gid_t id;
+
+ id = (gid_t)unix_id;
+ gid = make_kgid(&init_user_ns, id);
+ if (gid_valid(gid)) {
+ fgid = gid;
+ goto got_valid_id;
+ }
+ } else {
+ kuid_t uid;
+ uid_t id;
+
+ id = (uid_t)unix_id;
+ uid = make_kuid(&init_user_ns, id);
+ if (uid_valid(uid)) {
+ fuid = uid;
+ goto got_valid_id;
+ }
+ }
+ /* If unable to find uid/gid easily from SID try via upcall */
+ }
+
+try_upcall_to_get_id:
+ sidstr = sid_to_key_str(psid, sidtype);
+ if (!sidstr)
+ return -ENOMEM;
+
+ saved_cred = override_creds(root_cred);
+ sidkey = request_key(&cifs_idmap_key_type, sidstr, "");
+ if (IS_ERR(sidkey)) {
+ cifs_dbg(FYI, "%s: Can't map SID %s to a %cid\n",
+ __func__, sidstr, sidtype == SIDOWNER ? 'u' : 'g');
+ goto out_revert_creds;
+ }
+
+ /*
+ * FIXME: Here we assume that uid_t and gid_t are same size. It's
+ * probably a safe assumption but might be better to check based on
+ * sidtype.
+ */
+ BUILD_BUG_ON(sizeof(uid_t) != sizeof(gid_t));
+ if (sidkey->datalen != sizeof(uid_t)) {
+ cifs_dbg(FYI, "%s: Downcall contained malformed key (datalen=%hu)\n",
+ __func__, sidkey->datalen);
+ key_invalidate(sidkey);
+ goto out_key_put;
+ }
+
+ if (sidtype == SIDOWNER) {
+ kuid_t uid;
+ uid_t id;
+ memcpy(&id, &sidkey->payload.data[0], sizeof(uid_t));
+ uid = make_kuid(&init_user_ns, id);
+ if (uid_valid(uid))
+ fuid = uid;
+ } else {
+ kgid_t gid;
+ gid_t id;
+ memcpy(&id, &sidkey->payload.data[0], sizeof(gid_t));
+ gid = make_kgid(&init_user_ns, id);
+ if (gid_valid(gid))
+ fgid = gid;
+ }
+
+out_key_put:
+ key_put(sidkey);
+out_revert_creds:
+ revert_creds(saved_cred);
+ kfree(sidstr);
+
+ /*
+ * Note that we return 0 here unconditionally. If the mapping
+ * fails then we just fall back to using the ctx->linux_uid/linux_gid.
+ */
+got_valid_id:
+ rc = 0;
+ if (sidtype == SIDOWNER)
+ fattr->cf_uid = fuid;
+ else
+ fattr->cf_gid = fgid;
+ return rc;
+}
+
+int
+init_cifs_idmap(void)
+{
+ struct cred *cred;
+ struct key *keyring;
+ int ret;
+
+ cifs_dbg(FYI, "Registering the %s key type\n",
+ cifs_idmap_key_type.name);
+
+ /* create an override credential set with a special thread keyring in
+ * which requests are cached
+ *
+ * this is used to prevent malicious redirections from being installed
+ * with add_key().
+ */
+ cred = prepare_kernel_cred(NULL);
+ if (!cred)
+ return -ENOMEM;
+
+ keyring = keyring_alloc(".cifs_idmap",
+ GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW | KEY_USR_READ,
+ KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
+ if (IS_ERR(keyring)) {
+ ret = PTR_ERR(keyring);
+ goto failed_put_cred;
+ }
+
+ ret = register_key_type(&cifs_idmap_key_type);
+ if (ret < 0)
+ goto failed_put_key;
+
+ /* instruct request_key() to use this special keyring as a cache for
+ * the results it looks up */
+ set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
+ cred->thread_keyring = keyring;
+ cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
+ root_cred = cred;
+
+ cifs_dbg(FYI, "cifs idmap keyring: %d\n", key_serial(keyring));
+ return 0;
+
+failed_put_key:
+ key_put(keyring);
+failed_put_cred:
+ put_cred(cred);
+ return ret;
+}
+
+void
+exit_cifs_idmap(void)
+{
+ key_revoke(root_cred->thread_keyring);
+ unregister_key_type(&cifs_idmap_key_type);
+ put_cred(root_cred);
+ cifs_dbg(FYI, "Unregistered %s key type\n", cifs_idmap_key_type.name);
+}
+
+/* copy ntsd, owner sid, and group sid from a security descriptor to another */
+static __u32 copy_sec_desc(const struct cifs_ntsd *pntsd,
+ struct cifs_ntsd *pnntsd,
+ __u32 sidsoffset,
+ struct cifs_sid *pownersid,
+ struct cifs_sid *pgrpsid)
+{
+ struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
+ struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr;
+
+ /* copy security descriptor control portion */
+ pnntsd->revision = pntsd->revision;
+ pnntsd->type = pntsd->type;
+ pnntsd->dacloffset = cpu_to_le32(sizeof(struct cifs_ntsd));
+ pnntsd->sacloffset = 0;
+ pnntsd->osidoffset = cpu_to_le32(sidsoffset);
+ pnntsd->gsidoffset = cpu_to_le32(sidsoffset + sizeof(struct cifs_sid));
+
+ /* copy owner sid */
+ if (pownersid)
+ owner_sid_ptr = pownersid;
+ else
+ owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->osidoffset));
+ nowner_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset);
+ cifs_copy_sid(nowner_sid_ptr, owner_sid_ptr);
+
+ /* copy group sid */
+ if (pgrpsid)
+ group_sid_ptr = pgrpsid;
+ else
+ group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->gsidoffset));
+ ngroup_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset +
+ sizeof(struct cifs_sid));
+ cifs_copy_sid(ngroup_sid_ptr, group_sid_ptr);
+
+ return sidsoffset + (2 * sizeof(struct cifs_sid));
+}
+
+
+/*
+ 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 void access_flags_to_mode(__le32 ace_flags, int type, umode_t *pmode,
+ umode_t *pdenied, umode_t mask)
+{
+ __u32 flags = le32_to_cpu(ace_flags);
+ /*
+ * Do not assume "preferred" or "canonical" order.
+ * The first DENY or ALLOW ACE which matches perfectly is
+ * the permission to be used. Once allowed or denied, same
+ * permission in later ACEs do not matter.
+ */
+
+ /* If not already allowed, deny these bits */
+ if (type == ACCESS_DENIED) {
+ if (flags & GENERIC_ALL &&
+ !(*pmode & mask & 0777))
+ *pdenied |= mask & 0777;
+
+ if (((flags & GENERIC_WRITE) ||
+ ((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS)) &&
+ !(*pmode & mask & 0222))
+ *pdenied |= mask & 0222;
+
+ if (((flags & GENERIC_READ) ||
+ ((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS)) &&
+ !(*pmode & mask & 0444))
+ *pdenied |= mask & 0444;
+
+ if (((flags & GENERIC_EXECUTE) ||
+ ((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS)) &&
+ !(*pmode & mask & 0111))
+ *pdenied |= mask & 0111;
+
+ return;
+ } else if (type != ACCESS_ALLOWED) {
+ cifs_dbg(VFS, "unknown access control type %d\n", type);
+ return;
+ }
+ /* else ACCESS_ALLOWED type */
+
+ if ((flags & GENERIC_ALL) &&
+ !(*pdenied & mask & 0777)) {
+ *pmode |= mask & 0777;
+ cifs_dbg(NOISY, "all perms\n");
+ return;
+ }
+
+ if (((flags & GENERIC_WRITE) ||
+ ((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS)) &&
+ !(*pdenied & mask & 0222))
+ *pmode |= mask & 0222;
+
+ if (((flags & GENERIC_READ) ||
+ ((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS)) &&
+ !(*pdenied & mask & 0444))
+ *pmode |= mask & 0444;
+
+ if (((flags & GENERIC_EXECUTE) ||
+ ((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS)) &&
+ !(*pdenied & mask & 0111))
+ *pmode |= mask & 0111;
+
+ /* If DELETE_CHILD is set only on an owner ACE, set sticky bit */
+ if (flags & FILE_DELETE_CHILD) {
+ if (mask == ACL_OWNER_MASK) {
+ if (!(*pdenied & 01000))
+ *pmode |= 01000;
+ } else if (!(*pdenied & 01000)) {
+ *pmode &= ~01000;
+ *pdenied |= 01000;
+ }
+ }
+
+ cifs_dbg(NOISY, "access flags 0x%x mode now %04o\n", flags, *pmode);
+ return;
+}
+
+/*
+ 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 & S_IRUGO)
+ *pace_flags |= SET_FILE_READ_RIGHTS;
+ if (mode & S_IWUGO)
+ *pace_flags |= SET_FILE_WRITE_RIGHTS;
+ if (mode & S_IXUGO)
+ *pace_flags |= SET_FILE_EXEC_RIGHTS;
+
+ cifs_dbg(NOISY, "mode: %04o, access flags now 0x%x\n",
+ mode, *pace_flags);
+ return;
+}
+
+static __u16 cifs_copy_ace(struct cifs_ace *dst, struct cifs_ace *src, struct cifs_sid *psid)
+{
+ __u16 size = 1 + 1 + 2 + 4;
+
+ dst->type = src->type;
+ dst->flags = src->flags;
+ dst->access_req = src->access_req;
+
+ /* Check if there's a replacement sid specified */
+ if (psid)
+ size += cifs_copy_sid(&dst->sid, psid);
+ else
+ size += cifs_copy_sid(&dst->sid, &src->sid);
+
+ dst->size = cpu_to_le16(size);
+
+ return size;
+}
+
+static __u16 fill_ace_for_sid(struct cifs_ace *pntace,
+ const struct cifs_sid *psid, __u64 nmode,
+ umode_t bits, __u8 access_type,
+ bool allow_delete_child)
+{
+ int i;
+ __u16 size = 0;
+ __u32 access_req = 0;
+
+ pntace->type = access_type;
+ pntace->flags = 0x0;
+ mode_to_access_flags(nmode, bits, &access_req);
+
+ if (access_type == ACCESS_ALLOWED && allow_delete_child)
+ access_req |= FILE_DELETE_CHILD;
+
+ if (access_type == ACCESS_ALLOWED && !access_req)
+ access_req = SET_MINIMUM_RIGHTS;
+ else if (access_type == ACCESS_DENIED)
+ 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;
+}
+
+
+#ifdef CONFIG_CIFS_DEBUG2
+static void dump_ace(struct cifs_ace *pace, char *end_of_acl)
+{
+ int num_subauth;
+
+ /* validate that we do not go past end of acl */
+
+ if (le16_to_cpu(pace->size) < 16) {
+ cifs_dbg(VFS, "ACE too small %d\n", le16_to_cpu(pace->size));
+ return;
+ }
+
+ if (end_of_acl < (char *)pace + le16_to_cpu(pace->size)) {
+ cifs_dbg(VFS, "ACL too small to parse ACE\n");
+ return;
+ }
+
+ num_subauth = pace->sid.num_subauth;
+ if (num_subauth) {
+ int i;
+ cifs_dbg(FYI, "ACE revision %d num_auth %d type %d flags %d size %d\n",
+ pace->sid.revision, pace->sid.num_subauth, pace->type,
+ pace->flags, le16_to_cpu(pace->size));
+ for (i = 0; i < num_subauth; ++i) {
+ cifs_dbg(FYI, "ACE sub_auth[%d]: 0x%x\n",
+ i, le32_to_cpu(pace->sid.sub_auth[i]));
+ }
+
+ /* BB add length check to make sure that we do not have huge
+ num auths and therefore go off the end */
+ }
+
+ return;
+}
+#endif
+
+static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
+ struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
+ struct cifs_fattr *fattr, bool mode_from_special_sid)
+{
+ int i;
+ int num_aces = 0;
+ int acl_size;
+ char *acl_base;
+ struct cifs_ace **ppace;
+
+ /* BB need to add parm so we can store the SID BB */
+
+ if (!pdacl) {
+ /* no DACL in the security descriptor, set
+ all the permissions for user/group/other */
+ fattr->cf_mode |= 0777;
+ return;
+ }
+
+ /* validate that we do not go past end of acl */
+ if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
+ cifs_dbg(VFS, "ACL too small to parse DACL\n");
+ return;
+ }
+
+ cifs_dbg(NOISY, "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));
+
+ /* 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 */
+ fattr->cf_mode &= ~(0777);
+
+ acl_base = (char *)pdacl;
+ acl_size = sizeof(struct cifs_acl);
+
+ num_aces = le32_to_cpu(pdacl->num_aces);
+ if (num_aces > 0) {
+ umode_t denied_mode = 0;
+
+ if (num_aces > ULONG_MAX / sizeof(struct cifs_ace *))
+ return;
+ ppace = kmalloc_array(num_aces, sizeof(struct cifs_ace *),
+ GFP_KERNEL);
+ if (!ppace)
+ return;
+
+ for (i = 0; i < num_aces; ++i) {
+ ppace[i] = (struct cifs_ace *) (acl_base + acl_size);
+#ifdef CONFIG_CIFS_DEBUG2
+ dump_ace(ppace[i], end_of_acl);
+#endif
+ if (mode_from_special_sid &&
+ (compare_sids(&(ppace[i]->sid),
+ &sid_unix_NFS_mode) == 0)) {
+ /*
+ * Full permissions are:
+ * 07777 = S_ISUID | S_ISGID | S_ISVTX |
+ * S_IRWXU | S_IRWXG | S_IRWXO
+ */
+ fattr->cf_mode &= ~07777;
+ fattr->cf_mode |=
+ le32_to_cpu(ppace[i]->sid.sub_auth[2]);
+ break;
+ } else {
+ if (compare_sids(&(ppace[i]->sid), pownersid) == 0) {
+ access_flags_to_mode(ppace[i]->access_req,
+ ppace[i]->type,
+ &fattr->cf_mode,
+ &denied_mode,
+ ACL_OWNER_MASK);
+ } else if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0) {
+ access_flags_to_mode(ppace[i]->access_req,
+ ppace[i]->type,
+ &fattr->cf_mode,
+ &denied_mode,
+ ACL_GROUP_MASK);
+ } else if ((compare_sids(&(ppace[i]->sid), &sid_everyone) == 0) ||
+ (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0)) {
+ access_flags_to_mode(ppace[i]->access_req,
+ ppace[i]->type,
+ &fattr->cf_mode,
+ &denied_mode,
+ ACL_EVERYONE_MASK);
+ }
+ }
+
+
+/* memcpy((void *)(&(cifscred->aces[i])),
+ (void *)ppace[i],
+ sizeof(struct cifs_ace)); */
+
+ acl_base = (char *)ppace[i];
+ acl_size = le16_to_cpu(ppace[i]->size);
+ }
+
+ kfree(ppace);
+ }
+
+ return;
+}
+
+unsigned int setup_authusers_ACE(struct cifs_ace *pntace)
+{
+ int i;
+ unsigned int ace_size = 20;
+
+ pntace->type = ACCESS_ALLOWED_ACE_TYPE;
+ pntace->flags = 0x0;
+ pntace->access_req = cpu_to_le32(GENERIC_ALL);
+ pntace->sid.num_subauth = 1;
+ pntace->sid.revision = 1;
+ for (i = 0; i < NUM_AUTHS; i++)
+ pntace->sid.authority[i] = sid_authusers.authority[i];
+
+ pntace->sid.sub_auth[0] = sid_authusers.sub_auth[0];
+
+ /* size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth*4) */
+ pntace->size = cpu_to_le16(ace_size);
+ return ace_size;
+}
+
+/*
+ * Fill in the special SID based on the mode. See
+ * https://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
+ */
+unsigned int setup_special_mode_ACE(struct cifs_ace *pntace, __u64 nmode)
+{
+ int i;
+ unsigned int ace_size = 28;
+
+ pntace->type = ACCESS_DENIED_ACE_TYPE;
+ pntace->flags = 0x0;
+ pntace->access_req = 0;
+ pntace->sid.num_subauth = 3;
+ pntace->sid.revision = 1;
+ for (i = 0; i < NUM_AUTHS; i++)
+ pntace->sid.authority[i] = sid_unix_NFS_mode.authority[i];
+
+ pntace->sid.sub_auth[0] = sid_unix_NFS_mode.sub_auth[0];
+ pntace->sid.sub_auth[1] = sid_unix_NFS_mode.sub_auth[1];
+ pntace->sid.sub_auth[2] = cpu_to_le32(nmode & 07777);
+
+ /* size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth*4) */
+ pntace->size = cpu_to_le16(ace_size);
+ return ace_size;
+}
+
+unsigned int setup_special_user_owner_ACE(struct cifs_ace *pntace)
+{
+ int i;
+ unsigned int ace_size = 28;
+
+ pntace->type = ACCESS_ALLOWED_ACE_TYPE;
+ pntace->flags = 0x0;
+ pntace->access_req = cpu_to_le32(GENERIC_ALL);
+ pntace->sid.num_subauth = 3;
+ pntace->sid.revision = 1;
+ for (i = 0; i < NUM_AUTHS; i++)
+ pntace->sid.authority[i] = sid_unix_NFS_users.authority[i];
+
+ pntace->sid.sub_auth[0] = sid_unix_NFS_users.sub_auth[0];
+ pntace->sid.sub_auth[1] = sid_unix_NFS_users.sub_auth[1];
+ pntace->sid.sub_auth[2] = cpu_to_le32(current_fsgid().val);
+
+ /* size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth*4) */
+ pntace->size = cpu_to_le16(ace_size);
+ return ace_size;
+}
+
+static void populate_new_aces(char *nacl_base,
+ struct cifs_sid *pownersid,
+ struct cifs_sid *pgrpsid,
+ __u64 *pnmode, u32 *pnum_aces, u16 *pnsize,
+ bool modefromsid)
+{
+ __u64 nmode;
+ u32 num_aces = 0;
+ u16 nsize = 0;
+ __u64 user_mode;
+ __u64 group_mode;
+ __u64 other_mode;
+ __u64 deny_user_mode = 0;
+ __u64 deny_group_mode = 0;
+ bool sticky_set = false;
+ struct cifs_ace *pnntace = NULL;
+
+ nmode = *pnmode;
+ num_aces = *pnum_aces;
+ nsize = *pnsize;
+
+ if (modefromsid) {
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += setup_special_mode_ACE(pnntace, nmode);
+ num_aces++;
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += setup_authusers_ACE(pnntace);
+ num_aces++;
+ goto set_size;
+ }
+
+ /*
+ * We'll try to keep the mode as requested by the user.
+ * But in cases where we cannot meaningfully convert that
+ * into ACL, return back the updated mode, so that it is
+ * updated in the inode.
+ */
+
+ if (!memcmp(pownersid, pgrpsid, sizeof(struct cifs_sid))) {
+ /*
+ * Case when owner and group SIDs are the same.
+ * Set the more restrictive of the two modes.
+ */
+ user_mode = nmode & (nmode << 3) & 0700;
+ group_mode = nmode & (nmode >> 3) & 0070;
+ } else {
+ user_mode = nmode & 0700;
+ group_mode = nmode & 0070;
+ }
+
+ other_mode = nmode & 0007;
+
+ /* We need DENY ACE when the perm is more restrictive than the next sets. */
+ deny_user_mode = ~(user_mode) & ((group_mode << 3) | (other_mode << 6)) & 0700;
+ deny_group_mode = ~(group_mode) & (other_mode << 3) & 0070;
+
+ *pnmode = user_mode | group_mode | other_mode | (nmode & ~0777);
+
+ /* This tells if we should allow delete child for group and everyone. */
+ if (nmode & 01000)
+ sticky_set = true;
+
+ if (deny_user_mode) {
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += fill_ace_for_sid(pnntace, pownersid, deny_user_mode,
+ 0700, ACCESS_DENIED, false);
+ num_aces++;
+ }
+
+ /* Group DENY ACE does not conflict with owner ALLOW ACE. Keep in preferred order*/
+ if (deny_group_mode && !(deny_group_mode & (user_mode >> 3))) {
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += fill_ace_for_sid(pnntace, pgrpsid, deny_group_mode,
+ 0070, ACCESS_DENIED, false);
+ num_aces++;
+ }
+
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += fill_ace_for_sid(pnntace, pownersid, user_mode,
+ 0700, ACCESS_ALLOWED, true);
+ num_aces++;
+
+ /* Group DENY ACE conflicts with owner ALLOW ACE. So keep it after. */
+ if (deny_group_mode && (deny_group_mode & (user_mode >> 3))) {
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += fill_ace_for_sid(pnntace, pgrpsid, deny_group_mode,
+ 0070, ACCESS_DENIED, false);
+ num_aces++;
+ }
+
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += fill_ace_for_sid(pnntace, pgrpsid, group_mode,
+ 0070, ACCESS_ALLOWED, !sticky_set);
+ num_aces++;
+
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+ nsize += fill_ace_for_sid(pnntace, &sid_everyone, other_mode,
+ 0007, ACCESS_ALLOWED, !sticky_set);
+ num_aces++;
+
+set_size:
+ *pnum_aces = num_aces;
+ *pnsize = nsize;
+}
+
+static __u16 replace_sids_and_copy_aces(struct cifs_acl *pdacl, struct cifs_acl *pndacl,
+ struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
+ struct cifs_sid *pnownersid, struct cifs_sid *pngrpsid)
+{
+ int i;
+ u16 size = 0;
+ struct cifs_ace *pntace = NULL;
+ char *acl_base = NULL;
+ u32 src_num_aces = 0;
+ u16 nsize = 0;
+ struct cifs_ace *pnntace = NULL;
+ char *nacl_base = NULL;
+ u16 ace_size = 0;
+
+ acl_base = (char *)pdacl;
+ size = sizeof(struct cifs_acl);
+ src_num_aces = le32_to_cpu(pdacl->num_aces);
+
+ nacl_base = (char *)pndacl;
+ nsize = sizeof(struct cifs_acl);
+
+ /* Go through all the ACEs */
+ for (i = 0; i < src_num_aces; ++i) {
+ pntace = (struct cifs_ace *) (acl_base + size);
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+
+ if (pnownersid && compare_sids(&pntace->sid, pownersid) == 0)
+ ace_size = cifs_copy_ace(pnntace, pntace, pnownersid);
+ else if (pngrpsid && compare_sids(&pntace->sid, pgrpsid) == 0)
+ ace_size = cifs_copy_ace(pnntace, pntace, pngrpsid);
+ else
+ ace_size = cifs_copy_ace(pnntace, pntace, NULL);
+
+ size += le16_to_cpu(pntace->size);
+ nsize += ace_size;
+ }
+
+ return nsize;
+}
+
+static int set_chmod_dacl(struct cifs_acl *pdacl, struct cifs_acl *pndacl,
+ struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
+ __u64 *pnmode, bool mode_from_sid)
+{
+ int i;
+ u16 size = 0;
+ struct cifs_ace *pntace = NULL;
+ char *acl_base = NULL;
+ u32 src_num_aces = 0;
+ u16 nsize = 0;
+ struct cifs_ace *pnntace = NULL;
+ char *nacl_base = NULL;
+ u32 num_aces = 0;
+ bool new_aces_set = false;
+
+ /* Assuming that pndacl and pnmode are never NULL */
+ nacl_base = (char *)pndacl;
+ nsize = sizeof(struct cifs_acl);
+
+ /* If pdacl is NULL, we don't have a src. Simply populate new ACL. */
+ if (!pdacl) {
+ populate_new_aces(nacl_base,
+ pownersid, pgrpsid,
+ pnmode, &num_aces, &nsize,
+ mode_from_sid);
+ goto finalize_dacl;
+ }
+
+ acl_base = (char *)pdacl;
+ size = sizeof(struct cifs_acl);
+ src_num_aces = le32_to_cpu(pdacl->num_aces);
+
+ /* Retain old ACEs which we can retain */
+ for (i = 0; i < src_num_aces; ++i) {
+ pntace = (struct cifs_ace *) (acl_base + size);
+
+ if (!new_aces_set && (pntace->flags & INHERITED_ACE)) {
+ /* Place the new ACEs in between existing explicit and inherited */
+ populate_new_aces(nacl_base,
+ pownersid, pgrpsid,
+ pnmode, &num_aces, &nsize,
+ mode_from_sid);
+
+ new_aces_set = true;
+ }
+
+ /* If it's any one of the ACE we're replacing, skip! */
+ if (((compare_sids(&pntace->sid, &sid_unix_NFS_mode) == 0) ||
+ (compare_sids(&pntace->sid, pownersid) == 0) ||
+ (compare_sids(&pntace->sid, pgrpsid) == 0) ||
+ (compare_sids(&pntace->sid, &sid_everyone) == 0) ||
+ (compare_sids(&pntace->sid, &sid_authusers) == 0))) {
+ goto next_ace;
+ }
+
+ /* update the pointer to the next ACE to populate*/
+ pnntace = (struct cifs_ace *) (nacl_base + nsize);
+
+ nsize += cifs_copy_ace(pnntace, pntace, NULL);
+ num_aces++;
+
+next_ace:
+ size += le16_to_cpu(pntace->size);
+ }
+
+ /* If inherited ACEs are not present, place the new ones at the tail */
+ if (!new_aces_set) {
+ populate_new_aces(nacl_base,
+ pownersid, pgrpsid,
+ pnmode, &num_aces, &nsize,
+ mode_from_sid);
+
+ new_aces_set = true;
+ }
+
+finalize_dacl:
+ pndacl->num_aces = cpu_to_le32(num_aces);
+ pndacl->size = cpu_to_le16(nsize);
+
+ return 0;
+}
+
+static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
+{
+ /* BB need to add parm so we can store the SID BB */
+
+ /* 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) {
+ cifs_dbg(VFS, "ACL too small to parse SID %p\n", psid);
+ return -EINVAL;
+ }
+
+#ifdef CONFIG_CIFS_DEBUG2
+ if (psid->num_subauth) {
+ int i;
+ cifs_dbg(FYI, "SID revision %d num_auth %d\n",
+ psid->revision, psid->num_subauth);
+
+ for (i = 0; i < psid->num_subauth; i++) {
+ cifs_dbg(FYI, "SID sub_auth[%d]: 0x%x\n",
+ i, le32_to_cpu(psid->sub_auth[i]));
+ }
+
+ /* BB add length check to make sure that we do not have huge
+ num auths and therefore go off the end */
+ cifs_dbg(FYI, "RID 0x%x\n",
+ le32_to_cpu(psid->sub_auth[psid->num_subauth-1]));
+ }
+#endif
+
+ return 0;
+}
+
+
+/* Convert CIFS ACL to POSIX form */
+static int parse_sec_desc(struct cifs_sb_info *cifs_sb,
+ struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr,
+ bool get_mode_from_special_sid)
+{
+ int rc = 0;
+ struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
+ struct cifs_acl *dacl_ptr; /* no need for SACL ptr */
+ char *end_of_acl = ((char *)pntsd) + acl_len;
+ __u32 dacloffset;
+
+ if (pntsd == NULL)
+ return -EIO;
+
+ owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->osidoffset));
+ group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->gsidoffset));
+ dacloffset = le32_to_cpu(pntsd->dacloffset);
+ dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
+ cifs_dbg(NOISY, "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);
+/* cifs_dump_mem("owner_sid: ", owner_sid_ptr, 64); */
+ rc = parse_sid(owner_sid_ptr, end_of_acl);
+ if (rc) {
+ cifs_dbg(FYI, "%s: Error %d parsing Owner SID\n", __func__, rc);
+ return rc;
+ }
+ rc = sid_to_id(cifs_sb, owner_sid_ptr, fattr, SIDOWNER);
+ if (rc) {
+ cifs_dbg(FYI, "%s: Error %d mapping Owner SID to uid\n",
+ __func__, rc);
+ return rc;
+ }
+
+ rc = parse_sid(group_sid_ptr, end_of_acl);
+ if (rc) {
+ cifs_dbg(FYI, "%s: Error %d mapping Owner SID to gid\n",
+ __func__, rc);
+ return rc;
+ }
+ rc = sid_to_id(cifs_sb, group_sid_ptr, fattr, SIDGROUP);
+ if (rc) {
+ cifs_dbg(FYI, "%s: Error %d mapping Group SID to gid\n",
+ __func__, rc);
+ return rc;
+ }
+
+ if (dacloffset)
+ parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr,
+ group_sid_ptr, fattr, get_mode_from_special_sid);
+ else
+ cifs_dbg(FYI, "no ACL\n"); /* BB grant all or default perms? */
+
+ return rc;
+}
+
+/* Convert permission bits from mode to equivalent CIFS ACL */
+static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
+ __u32 secdesclen, __u32 *pnsecdesclen, __u64 *pnmode, kuid_t uid, kgid_t gid,
+ bool mode_from_sid, bool id_from_sid, int *aclflag)
+{
+ int rc = 0;
+ __u32 dacloffset;
+ __u32 ndacloffset;
+ __u32 sidsoffset;
+ struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
+ struct cifs_sid *nowner_sid_ptr = NULL, *ngroup_sid_ptr = NULL;
+ struct cifs_acl *dacl_ptr = NULL; /* no need for SACL ptr */
+ struct cifs_acl *ndacl_ptr = NULL; /* no need for SACL ptr */
+ char *end_of_acl = ((char *)pntsd) + secdesclen;
+ u16 size = 0;
+
+ dacloffset = le32_to_cpu(pntsd->dacloffset);
+ if (dacloffset) {
+ dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
+ if (end_of_acl < (char *)dacl_ptr + le16_to_cpu(dacl_ptr->size)) {
+ cifs_dbg(VFS, "Server returned illegal ACL size\n");
+ return -EINVAL;
+ }
+ }
+
+ owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->osidoffset));
+ group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->gsidoffset));
+
+ if (pnmode && *pnmode != NO_CHANGE_64) { /* chmod */
+ ndacloffset = sizeof(struct cifs_ntsd);
+ ndacl_ptr = (struct cifs_acl *)((char *)pnntsd + ndacloffset);
+ ndacl_ptr->revision =
+ dacloffset ? dacl_ptr->revision : cpu_to_le16(ACL_REVISION);
+
+ ndacl_ptr->size = cpu_to_le16(0);
+ ndacl_ptr->num_aces = cpu_to_le32(0);
+
+ rc = set_chmod_dacl(dacl_ptr, ndacl_ptr, owner_sid_ptr, group_sid_ptr,
+ pnmode, mode_from_sid);
+
+ sidsoffset = ndacloffset + le16_to_cpu(ndacl_ptr->size);
+ /* copy the non-dacl portion of secdesc */
+ *pnsecdesclen = copy_sec_desc(pntsd, pnntsd, sidsoffset,
+ NULL, NULL);
+
+ *aclflag |= CIFS_ACL_DACL;
+ } else {
+ ndacloffset = sizeof(struct cifs_ntsd);
+ ndacl_ptr = (struct cifs_acl *)((char *)pnntsd + ndacloffset);
+ ndacl_ptr->revision =
+ dacloffset ? dacl_ptr->revision : cpu_to_le16(ACL_REVISION);
+ ndacl_ptr->num_aces = dacl_ptr ? dacl_ptr->num_aces : 0;
+
+ if (uid_valid(uid)) { /* chown */
+ uid_t id;
+ nowner_sid_ptr = kzalloc(sizeof(struct cifs_sid),
+ GFP_KERNEL);
+ if (!nowner_sid_ptr) {
+ rc = -ENOMEM;
+ goto chown_chgrp_exit;
+ }
+ id = from_kuid(&init_user_ns, uid);
+ if (id_from_sid) {
+ struct owner_sid *osid = (struct owner_sid *)nowner_sid_ptr;
+ /* Populate the user ownership fields S-1-5-88-1 */
+ osid->Revision = 1;
+ osid->NumAuth = 3;
+ osid->Authority[5] = 5;
+ osid->SubAuthorities[0] = cpu_to_le32(88);
+ osid->SubAuthorities[1] = cpu_to_le32(1);
+ osid->SubAuthorities[2] = cpu_to_le32(id);
+
+ } else { /* lookup sid with upcall */
+ rc = id_to_sid(id, SIDOWNER, nowner_sid_ptr);
+ if (rc) {
+ cifs_dbg(FYI, "%s: Mapping error %d for owner id %d\n",
+ __func__, rc, id);
+ goto chown_chgrp_exit;
+ }
+ }
+ *aclflag |= CIFS_ACL_OWNER;
+ }
+ if (gid_valid(gid)) { /* chgrp */
+ gid_t id;
+ ngroup_sid_ptr = kzalloc(sizeof(struct cifs_sid),
+ GFP_KERNEL);
+ if (!ngroup_sid_ptr) {
+ rc = -ENOMEM;
+ goto chown_chgrp_exit;
+ }
+ id = from_kgid(&init_user_ns, gid);
+ if (id_from_sid) {
+ struct owner_sid *gsid = (struct owner_sid *)ngroup_sid_ptr;
+ /* Populate the group ownership fields S-1-5-88-2 */
+ gsid->Revision = 1;
+ gsid->NumAuth = 3;
+ gsid->Authority[5] = 5;
+ gsid->SubAuthorities[0] = cpu_to_le32(88);
+ gsid->SubAuthorities[1] = cpu_to_le32(2);
+ gsid->SubAuthorities[2] = cpu_to_le32(id);
+
+ } else { /* lookup sid with upcall */
+ rc = id_to_sid(id, SIDGROUP, ngroup_sid_ptr);
+ if (rc) {
+ cifs_dbg(FYI, "%s: Mapping error %d for group id %d\n",
+ __func__, rc, id);
+ goto chown_chgrp_exit;
+ }
+ }
+ *aclflag |= CIFS_ACL_GROUP;
+ }
+
+ if (dacloffset) {
+ /* Replace ACEs for old owner with new one */
+ size = replace_sids_and_copy_aces(dacl_ptr, ndacl_ptr,
+ owner_sid_ptr, group_sid_ptr,
+ nowner_sid_ptr, ngroup_sid_ptr);
+ ndacl_ptr->size = cpu_to_le16(size);
+ }
+
+ sidsoffset = ndacloffset + le16_to_cpu(ndacl_ptr->size);
+ /* copy the non-dacl portion of secdesc */
+ *pnsecdesclen = copy_sec_desc(pntsd, pnntsd, sidsoffset,
+ nowner_sid_ptr, ngroup_sid_ptr);
+
+chown_chgrp_exit:
+ /* errors could jump here. So make sure we return soon after this */
+ kfree(nowner_sid_ptr);
+ kfree(ngroup_sid_ptr);
+ }
+
+ return rc;
+}
+
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
+struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
+ const struct cifs_fid *cifsfid, u32 *pacllen,
+ u32 __maybe_unused unused)
+{
+ struct cifs_ntsd *pntsd = NULL;
+ unsigned int xid;
+ int rc;
+ struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+
+ if (IS_ERR(tlink))
+ return ERR_CAST(tlink);
+
+ xid = get_xid();
+ rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), cifsfid->netfid, &pntsd,
+ pacllen);
+ free_xid(xid);
+
+ cifs_put_tlink(tlink);
+
+ cifs_dbg(FYI, "%s: rc = %d ACL len %d\n", __func__, rc, *pacllen);
+ if (rc)
+ return ERR_PTR(rc);
+ return pntsd;
+}
+
+static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
+ const char *path, u32 *pacllen)
+{
+ struct cifs_ntsd *pntsd = NULL;
+ int oplock = 0;
+ unsigned int xid;
+ int rc;
+ struct cifs_tcon *tcon;
+ struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+ struct cifs_fid fid;
+ struct cifs_open_parms oparms;
+
+ if (IS_ERR(tlink))
+ return ERR_CAST(tlink);
+
+ tcon = tlink_tcon(tlink);
+ xid = get_xid();
+
+ oparms = (struct cifs_open_parms) {
+ .tcon = tcon,
+ .cifs_sb = cifs_sb,
+ .desired_access = READ_CONTROL,
+ .create_options = cifs_create_options(cifs_sb, 0),
+ .disposition = FILE_OPEN,
+ .path = path,
+ .fid = &fid,
+ };
+
+ rc = CIFS_open(xid, &oparms, &oplock, NULL);
+ if (!rc) {
+ rc = CIFSSMBGetCIFSACL(xid, tcon, fid.netfid, &pntsd, pacllen);
+ CIFSSMBClose(xid, tcon, fid.netfid);
+ }
+
+ cifs_put_tlink(tlink);
+ free_xid(xid);
+
+ cifs_dbg(FYI, "%s: rc = %d ACL len %d\n", __func__, rc, *pacllen);
+ if (rc)
+ return ERR_PTR(rc);
+ return pntsd;
+}
+
+/* Retrieve an ACL from the server */
+struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
+ struct inode *inode, const char *path,
+ u32 *pacllen, u32 info)
+{
+ struct cifs_ntsd *pntsd = NULL;
+ struct cifsFileInfo *open_file = NULL;
+
+ if (inode)
+ open_file = find_readable_file(CIFS_I(inode), true);
+ if (!open_file)
+ return get_cifs_acl_by_path(cifs_sb, path, pacllen);
+
+ pntsd = get_cifs_acl_by_fid(cifs_sb, &open_file->fid, pacllen, info);
+ cifsFileInfo_put(open_file);
+ return pntsd;
+}
+
+ /* Set an ACL on the server */
+int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
+ struct inode *inode, const char *path, int aclflag)
+{
+ int oplock = 0;
+ unsigned int xid;
+ int rc, access_flags;
+ struct cifs_tcon *tcon;
+ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+ struct cifs_fid fid;
+ struct cifs_open_parms oparms;
+
+ if (IS_ERR(tlink))
+ return PTR_ERR(tlink);
+
+ tcon = tlink_tcon(tlink);
+ xid = get_xid();
+
+ if (aclflag == CIFS_ACL_OWNER || aclflag == CIFS_ACL_GROUP)
+ access_flags = WRITE_OWNER;
+ else
+ access_flags = WRITE_DAC;
+
+ oparms = (struct cifs_open_parms) {
+ .tcon = tcon,
+ .cifs_sb = cifs_sb,
+ .desired_access = access_flags,
+ .create_options = cifs_create_options(cifs_sb, 0),
+ .disposition = FILE_OPEN,
+ .path = path,
+ .fid = &fid,
+ };
+
+ rc = CIFS_open(xid, &oparms, &oplock, NULL);
+ if (rc) {
+ cifs_dbg(VFS, "Unable to open file to set ACL\n");
+ goto out;
+ }
+
+ rc = CIFSSMBSetCIFSACL(xid, tcon, fid.netfid, pnntsd, acllen, aclflag);
+ cifs_dbg(NOISY, "SetCIFSACL rc = %d\n", rc);
+
+ CIFSSMBClose(xid, tcon, fid.netfid);
+out:
+ free_xid(xid);
+ cifs_put_tlink(tlink);
+ return rc;
+}
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
+
+/* Translate the CIFS ACL (similar to NTFS ACL) for a file into mode bits */
+int
+cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
+ struct inode *inode, bool mode_from_special_sid,
+ const char *path, const struct cifs_fid *pfid)
+{
+ struct cifs_ntsd *pntsd = NULL;
+ u32 acllen = 0;
+ int rc = 0;
+ struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+ struct smb_version_operations *ops;
+ const u32 info = 0;
+
+ cifs_dbg(NOISY, "converting ACL to mode for %s\n", path);
+
+ if (IS_ERR(tlink))
+ return PTR_ERR(tlink);
+
+ ops = tlink_tcon(tlink)->ses->server->ops;
+
+ if (pfid && (ops->get_acl_by_fid))
+ pntsd = ops->get_acl_by_fid(cifs_sb, pfid, &acllen, info);
+ else if (ops->get_acl)
+ pntsd = ops->get_acl(cifs_sb, inode, path, &acllen, info);
+ else {
+ cifs_put_tlink(tlink);
+ return -EOPNOTSUPP;
+ }
+ /* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
+ if (IS_ERR(pntsd)) {
+ rc = PTR_ERR(pntsd);
+ cifs_dbg(VFS, "%s: error %d getting sec desc\n", __func__, rc);
+ } else if (mode_from_special_sid) {
+ rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr, true);
+ kfree(pntsd);
+ } else {
+ /* get approximated mode from ACL */
+ rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr, false);
+ kfree(pntsd);
+ if (rc)
+ cifs_dbg(VFS, "parse sec desc failed rc = %d\n", rc);
+ }
+
+ cifs_put_tlink(tlink);
+
+ return rc;
+}
+
+/* Convert mode bits to an ACL so we can update the ACL on the server */
+int
+id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
+ kuid_t uid, kgid_t gid)
+{
+ int rc = 0;
+ int aclflag = CIFS_ACL_DACL; /* default flag to set */
+ __u32 secdesclen = 0;
+ __u32 nsecdesclen = 0;
+ __u32 dacloffset = 0;
+ struct cifs_acl *dacl_ptr = NULL;
+ struct cifs_ntsd *pntsd = NULL; /* acl obtained from server */
+ struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */
+ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
+ struct smb_version_operations *ops;
+ bool mode_from_sid, id_from_sid;
+ const u32 info = 0;
+
+ if (IS_ERR(tlink))
+ return PTR_ERR(tlink);
+
+ ops = tlink_tcon(tlink)->ses->server->ops;
+
+ cifs_dbg(NOISY, "set ACL from mode for %s\n", path);
+
+ /* Get the security descriptor */
+
+ if (ops->get_acl == NULL) {
+ cifs_put_tlink(tlink);
+ return -EOPNOTSUPP;
+ }
+
+ pntsd = ops->get_acl(cifs_sb, inode, path, &secdesclen, info);
+ if (IS_ERR(pntsd)) {
+ rc = PTR_ERR(pntsd);
+ cifs_dbg(VFS, "%s: error %d getting sec desc\n", __func__, rc);
+ cifs_put_tlink(tlink);
+ return rc;
+ }
+
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID)
+ mode_from_sid = true;
+ else
+ mode_from_sid = false;
+
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UID_FROM_ACL)
+ id_from_sid = true;
+ else
+ id_from_sid = false;
+
+ /* Potentially, five new ACEs can be added to the ACL for U,G,O mapping */
+ nsecdesclen = secdesclen;
+ if (pnmode && *pnmode != NO_CHANGE_64) { /* chmod */
+ if (mode_from_sid)
+ nsecdesclen += 2 * sizeof(struct cifs_ace);
+ else /* cifsacl */
+ nsecdesclen += 5 * sizeof(struct cifs_ace);
+ } else { /* chown */
+ /* When ownership changes, changes new owner sid length could be different */
+ nsecdesclen = sizeof(struct cifs_ntsd) + (sizeof(struct cifs_sid) * 2);
+ dacloffset = le32_to_cpu(pntsd->dacloffset);
+ if (dacloffset) {
+ dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
+ if (mode_from_sid)
+ nsecdesclen +=
+ le32_to_cpu(dacl_ptr->num_aces) * sizeof(struct cifs_ace);
+ else /* cifsacl */
+ nsecdesclen += le16_to_cpu(dacl_ptr->size);
+ }
+ }
+
+ /*
+ * Add three ACEs for owner, group, everyone getting rid of other ACEs
+ * as chmod disables ACEs and set the security descriptor. Allocate
+ * memory for the smb header, set security descriptor request security
+ * descriptor parameters, and security descriptor itself
+ */
+ nsecdesclen = max_t(u32, nsecdesclen, DEFAULT_SEC_DESC_LEN);
+ pnntsd = kmalloc(nsecdesclen, GFP_KERNEL);
+ if (!pnntsd) {
+ kfree(pntsd);
+ cifs_put_tlink(tlink);
+ return -ENOMEM;
+ }
+
+ rc = build_sec_desc(pntsd, pnntsd, secdesclen, &nsecdesclen, pnmode, uid, gid,
+ mode_from_sid, id_from_sid, &aclflag);
+
+ cifs_dbg(NOISY, "build_sec_desc rc: %d\n", rc);
+
+ if (ops->set_acl == NULL)
+ rc = -EOPNOTSUPP;
+
+ if (!rc) {
+ /* Set the security descriptor */
+ rc = ops->set_acl(pnntsd, nsecdesclen, inode, path, aclflag);
+ cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc);
+ }
+ cifs_put_tlink(tlink);
+
+ kfree(pnntsd);
+ kfree(pntsd);
+ return rc;
+}