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-rw-r--r--fs/ntfs3/inode.c2
-rw-r--r--fs/ntfs3/xattr.c102
-rw-r--r--fs/overlayfs/overlayfs.h2
-rw-r--r--fs/overlayfs/super.c15
-rw-r--r--fs/posix_acl.c288
-rw-r--r--fs/xattr.c15
-rw-r--r--include/linux/posix_acl_xattr.h12
-rw-r--r--include/linux/xattr.h2
-rw-r--r--security/integrity/evm/evm_main.c17
9 files changed, 264 insertions, 191 deletions
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 51363d4e8636..26a76ebfe58f 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1927,8 +1927,6 @@ const struct inode_operations ntfs_link_inode_operations = {
.setattr = ntfs3_setattr,
.listxattr = ntfs_listxattr,
.permission = ntfs_permission,
- .get_acl = ntfs_get_acl,
- .set_acl = ntfs_set_acl,
};
const struct address_space_operations ntfs_aops = {
diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index 6ae1f56b7358..7de8718c68a9 100644
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -625,67 +625,6 @@ int ntfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
return ntfs_set_acl_ex(mnt_userns, inode, acl, type, false);
}
-static int ntfs_xattr_get_acl(struct user_namespace *mnt_userns,
- struct inode *inode, int type, void *buffer,
- size_t size)
-{
- struct posix_acl *acl;
- int err;
-
- if (!(inode->i_sb->s_flags & SB_POSIXACL)) {
- ntfs_inode_warn(inode, "add mount option \"acl\" to use acl");
- return -EOPNOTSUPP;
- }
-
- acl = ntfs_get_acl(inode, type, false);
- if (IS_ERR(acl))
- return PTR_ERR(acl);
-
- if (!acl)
- return -ENODATA;
-
- err = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
- posix_acl_release(acl);
-
- return err;
-}
-
-static int ntfs_xattr_set_acl(struct user_namespace *mnt_userns,
- struct inode *inode, int type, const void *value,
- size_t size)
-{
- struct posix_acl *acl;
- int err;
-
- if (!(inode->i_sb->s_flags & SB_POSIXACL)) {
- ntfs_inode_warn(inode, "add mount option \"acl\" to use acl");
- return -EOPNOTSUPP;
- }
-
- if (!inode_owner_or_capable(mnt_userns, inode))
- return -EPERM;
-
- if (!value) {
- acl = NULL;
- } else {
- acl = posix_acl_from_xattr(&init_user_ns, value, size);
- if (IS_ERR(acl))
- return PTR_ERR(acl);
-
- if (acl) {
- err = posix_acl_valid(&init_user_ns, acl);
- if (err)
- goto release_and_out;
- }
- }
-
- err = ntfs_set_acl(mnt_userns, inode, acl, type);
-
-release_and_out:
- posix_acl_release(acl);
- return err;
-}
-
/*
* ntfs_init_acl - Initialize the ACLs of a new inode.
*
@@ -852,23 +791,6 @@ static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
goto out;
}
-#ifdef CONFIG_NTFS3_FS_POSIX_ACL
- if ((name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1 &&
- !memcmp(name, XATTR_NAME_POSIX_ACL_ACCESS,
- sizeof(XATTR_NAME_POSIX_ACL_ACCESS))) ||
- (name_len == sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1 &&
- !memcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT,
- sizeof(XATTR_NAME_POSIX_ACL_DEFAULT)))) {
- /* TODO: init_user_ns? */
- err = ntfs_xattr_get_acl(
- &init_user_ns, inode,
- name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1
- ? ACL_TYPE_ACCESS
- : ACL_TYPE_DEFAULT,
- buffer, size);
- goto out;
- }
-#endif
/* Deal with NTFS extended attribute. */
err = ntfs_get_ea(inode, name, name_len, buffer, size, NULL);
@@ -981,22 +903,6 @@ set_new_fa:
goto out;
}
-#ifdef CONFIG_NTFS3_FS_POSIX_ACL
- if ((name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1 &&
- !memcmp(name, XATTR_NAME_POSIX_ACL_ACCESS,
- sizeof(XATTR_NAME_POSIX_ACL_ACCESS))) ||
- (name_len == sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1 &&
- !memcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT,
- sizeof(XATTR_NAME_POSIX_ACL_DEFAULT)))) {
- err = ntfs_xattr_set_acl(
- mnt_userns, inode,
- name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1
- ? ACL_TYPE_ACCESS
- : ACL_TYPE_DEFAULT,
- value, size);
- goto out;
- }
-#endif
/* Deal with NTFS extended attribute. */
err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
@@ -1086,7 +992,7 @@ static bool ntfs_xattr_user_list(struct dentry *dentry)
}
// clang-format off
-static const struct xattr_handler ntfs_xattr_handler = {
+static const struct xattr_handler ntfs_other_xattr_handler = {
.prefix = "",
.get = ntfs_getxattr,
.set = ntfs_setxattr,
@@ -1094,7 +1000,11 @@ static const struct xattr_handler ntfs_xattr_handler = {
};
const struct xattr_handler *ntfs_xattr_handlers[] = {
- &ntfs_xattr_handler,
+#ifdef CONFIG_NTFS3_FS_POSIX_ACL
+ &posix_acl_access_xattr_handler,
+ &posix_acl_default_xattr_handler,
+#endif
+ &ntfs_other_xattr_handler,
NULL,
};
// clang-format on
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 87759165d32b..ee93c825b06b 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -250,7 +250,7 @@ static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
size_t size, int flags)
{
int err = vfs_setxattr(ovl_upper_mnt_userns(ofs), dentry, name,
- (void *)value, size, flags);
+ value, size, flags);
pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n",
dentry, name, min((int)size, 48), value, size, flags, err);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index ec746d447f1b..5da771b218d1 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1022,7 +1022,20 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler,
/* Check that everything is OK before copy-up */
if (value) {
- acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ /* The above comment can be understood in two ways:
+ *
+ * 1. We just want to check whether the basic POSIX ACL format
+ * is ok. For example, if the header is correct and the size
+ * is sane.
+ * 2. We want to know whether the ACL_{GROUP,USER} entries can
+ * be mapped according to the underlying filesystem.
+ *
+ * Currently, we only check 1. If we wanted to check 2. we
+ * would need to pass the mnt_userns and the fs_userns of the
+ * underlying filesystem. But frankly, I think checking 1. is
+ * enough to start the copy-up.
+ */
+ acl = vfs_set_acl_prepare(&init_user_ns, &init_user_ns, value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 5af33800743e..b4f109875e79 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -710,9 +710,9 @@ EXPORT_SYMBOL(posix_acl_update_mode);
/*
* Fix up the uids and gids in posix acl extended attributes in place.
*/
-static int posix_acl_fix_xattr_common(void *value, size_t size)
+static int posix_acl_fix_xattr_common(const void *value, size_t size)
{
- struct posix_acl_xattr_header *header = value;
+ const struct posix_acl_xattr_header *header = value;
int count;
if (!header)
@@ -720,13 +720,13 @@ static int posix_acl_fix_xattr_common(void *value, size_t size)
if (size < sizeof(struct posix_acl_xattr_header))
return -EINVAL;
if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
- return -EINVAL;
+ return -EOPNOTSUPP;
count = posix_acl_xattr_count(size);
if (count < 0)
return -EINVAL;
if (count == 0)
- return -EINVAL;
+ return 0;
return count;
}
@@ -748,7 +748,7 @@ void posix_acl_getxattr_idmapped_mnt(struct user_namespace *mnt_userns,
return;
count = posix_acl_fix_xattr_common(value, size);
- if (count < 0)
+ if (count <= 0)
return;
for (end = entry + count; entry != end; entry++) {
@@ -771,46 +771,6 @@ void posix_acl_getxattr_idmapped_mnt(struct user_namespace *mnt_userns,
}
}
-void posix_acl_setxattr_idmapped_mnt(struct user_namespace *mnt_userns,
- const struct inode *inode,
- void *value, size_t size)
-{
- struct posix_acl_xattr_header *header = value;
- struct posix_acl_xattr_entry *entry = (void *)(header + 1), *end;
- struct user_namespace *fs_userns = i_user_ns(inode);
- int count;
- vfsuid_t vfsuid;
- vfsgid_t vfsgid;
- kuid_t uid;
- kgid_t gid;
-
- if (no_idmapping(mnt_userns, i_user_ns(inode)))
- return;
-
- count = posix_acl_fix_xattr_common(value, size);
- if (count < 0)
- return;
-
- for (end = entry + count; entry != end; entry++) {
- switch (le16_to_cpu(entry->e_tag)) {
- case ACL_USER:
- uid = make_kuid(&init_user_ns, le32_to_cpu(entry->e_id));
- vfsuid = VFSUIDT_INIT(uid);
- uid = from_vfsuid(mnt_userns, fs_userns, vfsuid);
- entry->e_id = cpu_to_le32(from_kuid(&init_user_ns, uid));
- break;
- case ACL_GROUP:
- gid = make_kgid(&init_user_ns, le32_to_cpu(entry->e_id));
- vfsgid = VFSGIDT_INIT(gid);
- gid = from_vfsgid(mnt_userns, fs_userns, vfsgid);
- entry->e_id = cpu_to_le32(from_kgid(&init_user_ns, gid));
- break;
- default:
- break;
- }
- }
-}
-
static void posix_acl_fix_xattr_userns(
struct user_namespace *to, struct user_namespace *from,
void *value, size_t size)
@@ -822,7 +782,7 @@ static void posix_acl_fix_xattr_userns(
kgid_t gid;
count = posix_acl_fix_xattr_common(value, size);
- if (count < 0)
+ if (count <= 0)
return;
for (end = entry + count; entry != end; entry++) {
@@ -857,12 +817,32 @@ void posix_acl_fix_xattr_to_user(void *value, size_t size)
posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
}
-/*
- * Convert from extended attribute to in-memory representation.
+/**
+ * make_posix_acl - convert POSIX ACLs from uapi to VFS format using the
+ * provided callbacks to map ACL_{GROUP,USER} entries into the
+ * appropriate format
+ * @mnt_userns: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @value: the uapi representation of POSIX ACLs
+ * @size: the size of @void
+ * @uid_cb: callback to use for mapping the uid stored in ACL_USER entries
+ * @gid_cb: callback to use for mapping the gid stored in ACL_GROUP entries
+ *
+ * The make_posix_acl() helper is an abstraction to translate from uapi format
+ * into the VFS format allowing the caller to specific callbacks to map
+ * ACL_{GROUP,USER} entries into the expected format. This is used in
+ * posix_acl_from_xattr() and vfs_set_acl_prepare() and avoids pointless code
+ * duplication.
+ *
+ * Return: Allocated struct posix_acl on success, NULL for a valid header but
+ * without actual POSIX ACL entries, or ERR_PTR() encoded error code.
*/
-struct posix_acl *
-posix_acl_from_xattr(struct user_namespace *user_ns,
- const void *value, size_t size)
+static struct posix_acl *make_posix_acl(struct user_namespace *mnt_userns,
+ struct user_namespace *fs_userns, const void *value, size_t size,
+ kuid_t (*uid_cb)(struct user_namespace *, struct user_namespace *,
+ const struct posix_acl_xattr_entry *),
+ kgid_t (*gid_cb)(struct user_namespace *, struct user_namespace *,
+ const struct posix_acl_xattr_entry *))
{
const struct posix_acl_xattr_header *header = value;
const struct posix_acl_xattr_entry *entry = (const void *)(header + 1), *end;
@@ -870,16 +850,9 @@ posix_acl_from_xattr(struct user_namespace *user_ns,
struct posix_acl *acl;
struct posix_acl_entry *acl_e;
- if (!value)
- return NULL;
- if (size < sizeof(struct posix_acl_xattr_header))
- return ERR_PTR(-EINVAL);
- if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
- return ERR_PTR(-EOPNOTSUPP);
-
- count = posix_acl_xattr_count(size);
+ count = posix_acl_fix_xattr_common(value, size);
if (count < 0)
- return ERR_PTR(-EINVAL);
+ return ERR_PTR(count);
if (count == 0)
return NULL;
@@ -900,16 +873,12 @@ posix_acl_from_xattr(struct user_namespace *user_ns,
break;
case ACL_USER:
- acl_e->e_uid =
- make_kuid(user_ns,
- le32_to_cpu(entry->e_id));
+ acl_e->e_uid = uid_cb(mnt_userns, fs_userns, entry);
if (!uid_valid(acl_e->e_uid))
goto fail;
break;
case ACL_GROUP:
- acl_e->e_gid =
- make_kgid(user_ns,
- le32_to_cpu(entry->e_id));
+ acl_e->e_gid = gid_cb(mnt_userns, fs_userns, entry);
if (!gid_valid(acl_e->e_gid))
goto fail;
break;
@@ -924,6 +893,181 @@ fail:
posix_acl_release(acl);
return ERR_PTR(-EINVAL);
}
+
+/**
+ * vfs_set_acl_prepare_kuid - map ACL_USER uid according to mount- and
+ * filesystem idmapping
+ * @mnt_userns: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @e: a ACL_USER entry in POSIX ACL uapi format
+ *
+ * The uid stored as ACL_USER entry in @e is a kuid_t stored as a raw {g,u}id
+ * value. The vfs_set_acl_prepare_kuid() will recover the kuid_t through
+ * KUIDT_INIT() and then map it according to the idmapped mount. The resulting
+ * kuid_t is the value which the filesystem can map up into a raw backing store
+ * id in the filesystem's idmapping.
+ *
+ * This is used in vfs_set_acl_prepare() to generate the proper VFS
+ * representation of POSIX ACLs with ACL_USER entries during setxattr().
+ *
+ * Return: A kuid in @fs_userns for the uid stored in @e.
+ */
+static inline kuid_t
+vfs_set_acl_prepare_kuid(struct user_namespace *mnt_userns,
+ struct user_namespace *fs_userns,
+ const struct posix_acl_xattr_entry *e)
+{
+ kuid_t kuid = KUIDT_INIT(le32_to_cpu(e->e_id));
+ return from_vfsuid(mnt_userns, fs_userns, VFSUIDT_INIT(kuid));
+}
+
+/**
+ * vfs_set_acl_prepare_kgid - map ACL_GROUP gid according to mount- and
+ * filesystem idmapping
+ * @mnt_userns: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @e: a ACL_GROUP entry in POSIX ACL uapi format
+ *
+ * The gid stored as ACL_GROUP entry in @e is a kgid_t stored as a raw {g,u}id
+ * value. The vfs_set_acl_prepare_kgid() will recover the kgid_t through
+ * KGIDT_INIT() and then map it according to the idmapped mount. The resulting
+ * kgid_t is the value which the filesystem can map up into a raw backing store
+ * id in the filesystem's idmapping.
+ *
+ * This is used in vfs_set_acl_prepare() to generate the proper VFS
+ * representation of POSIX ACLs with ACL_GROUP entries during setxattr().
+ *
+ * Return: A kgid in @fs_userns for the gid stored in @e.
+ */
+static inline kgid_t
+vfs_set_acl_prepare_kgid(struct user_namespace *mnt_userns,
+ struct user_namespace *fs_userns,
+ const struct posix_acl_xattr_entry *e)
+{
+ kgid_t kgid = KGIDT_INIT(le32_to_cpu(e->e_id));
+ return from_vfsgid(mnt_userns, fs_userns, VFSGIDT_INIT(kgid));
+}
+
+/**
+ * vfs_set_acl_prepare - convert POSIX ACLs from uapi to VFS format taking
+ * mount and filesystem idmappings into account
+ * @mnt_userns: the mount's idmapping
+ * @fs_userns: the filesystem's idmapping
+ * @value: the uapi representation of POSIX ACLs
+ * @size: the size of @void
+ *
+ * When setting POSIX ACLs with ACL_{GROUP,USER} entries they need to be
+ * mapped according to the relevant mount- and filesystem idmapping. It is
+ * important that the ACL_{GROUP,USER} entries in struct posix_acl will be
+ * mapped into k{g,u}id_t that are supposed to be mapped up in the filesystem
+ * idmapping. This is crucial since the resulting struct posix_acl might be
+ * cached filesystem wide. The vfs_set_acl_prepare() function will take care to
+ * perform all necessary idmappings.
+ *
+ * Note, that since basically forever the {g,u}id values encoded as
+ * ACL_{GROUP,USER} entries in the uapi POSIX ACLs passed via @value contain
+ * values that have been mapped according to the caller's idmapping. In other
+ * words, POSIX ACLs passed in uapi format as @value during setxattr() contain
+ * {g,u}id values in their ACL_{GROUP,USER} entries that should actually have
+ * been stored as k{g,u}id_t.
+ *
+ * This means, vfs_set_acl_prepare() needs to first recover the k{g,u}id_t by
+ * calling K{G,U}IDT_INIT(). Afterwards they can be interpreted as vfs{g,u}id_t
+ * through from_vfs{g,u}id() to account for any idmapped mounts. The
+ * vfs_set_acl_prepare_k{g,u}id() helpers will take care to generate the
+ * correct k{g,u}id_t.
+ *
+ * The filesystem will then receive the POSIX ACLs ready to be cached
+ * filesystem wide and ready to be written to the backing store taking the
+ * filesystem's idmapping into account.
+ *
+ * Return: Allocated struct posix_acl on success, NULL for a valid header but
+ * without actual POSIX ACL entries, or ERR_PTR() encoded error code.
+ */
+struct posix_acl *vfs_set_acl_prepare(struct user_namespace *mnt_userns,
+ struct user_namespace *fs_userns,
+ const void *value, size_t size)
+{
+ return make_posix_acl(mnt_userns, fs_userns, value, size,
+ vfs_set_acl_prepare_kuid,
+ vfs_set_acl_prepare_kgid);
+}
+EXPORT_SYMBOL(vfs_set_acl_prepare);
+
+/**
+ * posix_acl_from_xattr_kuid - map ACL_USER uid into filesystem idmapping
+ * @mnt_userns: unused
+ * @fs_userns: the filesystem's idmapping
+ * @e: a ACL_USER entry in POSIX ACL uapi format
+ *
+ * Map the uid stored as ACL_USER entry in @e into the filesystem's idmapping.
+ * This is used in posix_acl_from_xattr() to generate the proper VFS
+ * representation of POSIX ACLs with ACL_USER entries.
+ *
+ * Return: A kuid in @fs_userns for the uid stored in @e.
+ */
+static inline kuid_t
+posix_acl_from_xattr_kuid(struct user_namespace *mnt_userns,
+ struct user_namespace *fs_userns,
+ const struct posix_acl_xattr_entry *e)
+{
+ return make_kuid(fs_userns, le32_to_cpu(e->e_id));
+}
+
+/**
+ * posix_acl_from_xattr_kgid - map ACL_GROUP gid into filesystem idmapping
+ * @mnt_userns: unused
+ * @fs_userns: the filesystem's idmapping
+ * @e: a ACL_GROUP entry in POSIX ACL uapi format
+ *
+ * Map the gid stored as ACL_GROUP entry in @e into the filesystem's idmapping.
+ * This is used in posix_acl_from_xattr() to generate the proper VFS
+ * representation of POSIX ACLs with ACL_GROUP entries.
+ *
+ * Return: A kgid in @fs_userns for the gid stored in @e.
+ */
+static inline kgid_t
+posix_acl_from_xattr_kgid(struct user_namespace *mnt_userns,
+ struct user_namespace *fs_userns,
+ const struct posix_acl_xattr_entry *e)
+{
+ return make_kgid(fs_userns, le32_to_cpu(e->e_id));
+}
+
+/**
+ * posix_acl_from_xattr - convert POSIX ACLs from backing store to VFS format
+ * @fs_userns: the filesystem's idmapping
+ * @value: the uapi representation of POSIX ACLs
+ * @size: the size of @void
+ *
+ * Filesystems that store POSIX ACLs in the unaltered uapi format should use
+ * posix_acl_from_xattr() when reading them from the backing store and
+ * converting them into the struct posix_acl VFS format. The helper is
+ * specifically intended to be called from the ->get_acl() inode operation.
+ *
+ * The posix_acl_from_xattr() function will map the raw {g,u}id values stored
+ * in ACL_{GROUP,USER} entries into the filesystem idmapping in @fs_userns. The
+ * posix_acl_from_xattr_k{g,u}id() helpers will take care to generate the
+ * correct k{g,u}id_t. The returned struct posix_acl can be cached.
+ *
+ * Note that posix_acl_from_xattr() does not take idmapped mounts into account.
+ * If it did it calling is from the ->get_acl() inode operation would return
+ * POSIX ACLs mapped according to an idmapped mount which would mean that the
+ * value couldn't be cached for the filesystem. Idmapped mounts are taken into
+ * account on the fly during permission checking or right at the VFS -
+ * userspace boundary before reporting them to the user.
+ *
+ * Return: Allocated struct posix_acl on success, NULL for a valid header but
+ * without actual POSIX ACL entries, or ERR_PTR() encoded error code.
+ */
+struct posix_acl *
+posix_acl_from_xattr(struct user_namespace *fs_userns,
+ const void *value, size_t size)
+{
+ return make_posix_acl(&init_user_ns, fs_userns, value, size,
+ posix_acl_from_xattr_kuid,
+ posix_acl_from_xattr_kgid);
+}
EXPORT_SYMBOL (posix_acl_from_xattr);
/*
@@ -1027,7 +1171,17 @@ posix_acl_xattr_set(const struct xattr_handler *handler,
int ret;
if (value) {
- acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ /*
+ * By the time we end up here the {g,u}ids stored in
+ * ACL_{GROUP,USER} have already been mapped according to the
+ * caller's idmapping. The vfs_set_acl_prepare() helper will
+ * recover them and take idmapped mounts into account. The
+ * filesystem will receive the POSIX ACLs in the correct
+ * format ready to be cached or written to the backing store
+ * taking the filesystem idmapping into account.
+ */
+ acl = vfs_set_acl_prepare(mnt_userns, i_user_ns(inode),
+ value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
diff --git a/fs/xattr.c b/fs/xattr.c
index a1f4998bc6be..61107b6bbed2 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -290,7 +290,7 @@ static inline bool is_posix_acl_xattr(const char *name)
int
vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
- const char *name, void *value, size_t size, int flags)
+ const char *name, const void *value, size_t size, int flags)
{
struct inode *inode = dentry->d_inode;
struct inode *delegated_inode = NULL;
@@ -298,16 +298,12 @@ vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
int error;
if (size && strcmp(name, XATTR_NAME_CAPS) == 0) {
- error = cap_convert_nscap(mnt_userns, dentry,
- (const void **)&value, size);
+ error = cap_convert_nscap(mnt_userns, dentry, &value, size);
if (error < 0)
return error;
size = error;
}
- if (size && is_posix_acl_xattr(name))
- posix_acl_setxattr_idmapped_mnt(mnt_userns, inode, value, size);
-
retry_deleg:
inode_lock(inode);
error = __vfs_setxattr_locked(mnt_userns, dentry, name, value, size,
@@ -587,9 +583,7 @@ int setxattr_copy(const char __user *name, struct xattr_ctx *ctx)
static void setxattr_convert(struct user_namespace *mnt_userns,
struct dentry *d, struct xattr_ctx *ctx)
{
- if (ctx->size &&
- ((strcmp(ctx->kname->name, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
- (strcmp(ctx->kname->name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)))
+ if (ctx->size && is_posix_acl_xattr(ctx->kname->name))
posix_acl_fix_xattr_from_user(ctx->kvalue, ctx->size);
}
@@ -705,8 +699,7 @@ do_getxattr(struct user_namespace *mnt_userns, struct dentry *d,
error = vfs_getxattr(mnt_userns, d, kname, ctx->kvalue, ctx->size);
if (error > 0) {
- if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
- (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
+ if (is_posix_acl_xattr(kname))
posix_acl_fix_xattr_to_user(ctx->kvalue, error);
if (ctx->size && copy_to_user(ctx->value, ctx->kvalue, error))
error = -EFAULT;
diff --git a/include/linux/posix_acl_xattr.h b/include/linux/posix_acl_xattr.h
index b6bd3eac2bcc..8163dd48c430 100644
--- a/include/linux/posix_acl_xattr.h
+++ b/include/linux/posix_acl_xattr.h
@@ -38,9 +38,6 @@ void posix_acl_fix_xattr_to_user(void *value, size_t size);
void posix_acl_getxattr_idmapped_mnt(struct user_namespace *mnt_userns,
const struct inode *inode,
void *value, size_t size);
-void posix_acl_setxattr_idmapped_mnt(struct user_namespace *mnt_userns,
- const struct inode *inode,
- void *value, size_t size);
#else
static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
{
@@ -54,18 +51,15 @@ posix_acl_getxattr_idmapped_mnt(struct user_namespace *mnt_userns,
size_t size)
{
}
-static inline void
-posix_acl_setxattr_idmapped_mnt(struct user_namespace *mnt_userns,
- const struct inode *inode, void *value,
- size_t size)
-{
-}
#endif
struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
const void *value, size_t size);
int posix_acl_to_xattr(struct user_namespace *user_ns,
const struct posix_acl *acl, void *buffer, size_t size);
+struct posix_acl *vfs_set_acl_prepare(struct user_namespace *mnt_userns,
+ struct user_namespace *fs_userns,
+ const void *value, size_t size);
extern const struct xattr_handler posix_acl_access_xattr_handler;
extern const struct xattr_handler posix_acl_default_xattr_handler;
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 979a9d3e5bfb..4c379d23ec6e 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -61,7 +61,7 @@ int __vfs_setxattr_locked(struct user_namespace *, struct dentry *,
const char *, const void *, size_t, int,
struct inode **);
int vfs_setxattr(struct user_namespace *, struct dentry *, const char *,
- void *, size_t, int);
+ const void *, size_t, int);
int __vfs_removexattr(struct user_namespace *, struct dentry *, const char *);
int __vfs_removexattr_locked(struct user_namespace *, struct dentry *,
const char *, struct inode **);
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 2e6fb6e2ffd2..23d484e05e6f 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -457,10 +457,21 @@ static int evm_xattr_acl_change(struct user_namespace *mnt_userns,
int rc;
/*
- * user_ns is not relevant here, ACL_USER/ACL_GROUP don't have impact
- * on the inode mode (see posix_acl_equiv_mode()).
+ * An earlier comment here mentioned that the idmappings for
+ * ACL_{GROUP,USER} don't matter since EVM is only interested in the
+ * mode stored as part of POSIX ACLs. Nonetheless, if it must translate
+ * from the uapi POSIX ACL representation to the VFS internal POSIX ACL
+ * representation it should do so correctly. There's no guarantee that
+ * we won't change POSIX ACLs in a way that ACL_{GROUP,USER} matters
+ * for the mode at some point and it's difficult to keep track of all
+ * the LSM and integrity modules and what they do to POSIX ACLs.
+ *
+ * Frankly, EVM shouldn't try to interpret the uapi struct for POSIX
+ * ACLs it received. It requires knowledge that only the VFS is
+ * guaranteed to have.
*/
- acl = posix_acl_from_xattr(&init_user_ns, xattr_value, xattr_value_len);
+ acl = vfs_set_acl_prepare(mnt_userns, i_user_ns(inode),
+ xattr_value, xattr_value_len);
if (IS_ERR_OR_NULL(acl))
return 1;
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-02 19:50:30 +0000