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-rw-r--r--fs/posix_acl.c103
1 files changed, 74 insertions, 29 deletions
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 95882b3f5f62..f3309a7edb49 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -345,10 +345,13 @@ EXPORT_SYMBOL(posix_acl_from_mode);
* by the acl. Returns -E... otherwise.
*/
int
-posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
+posix_acl_permission(struct user_namespace *mnt_userns, struct inode *inode,
+ const struct posix_acl *acl, int want)
{
const struct posix_acl_entry *pa, *pe, *mask_obj;
int found = 0;
+ kuid_t uid;
+ kgid_t gid;
want &= MAY_READ | MAY_WRITE | MAY_EXEC;
@@ -356,22 +359,26 @@ posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
switch(pa->e_tag) {
case ACL_USER_OBJ:
/* (May have been checked already) */
- if (uid_eq(inode->i_uid, current_fsuid()))
+ uid = i_uid_into_mnt(mnt_userns, inode);
+ if (uid_eq(uid, current_fsuid()))
goto check_perm;
break;
case ACL_USER:
- if (uid_eq(pa->e_uid, current_fsuid()))
+ uid = kuid_into_mnt(mnt_userns, pa->e_uid);
+ if (uid_eq(uid, current_fsuid()))
goto mask;
break;
case ACL_GROUP_OBJ:
- if (in_group_p(inode->i_gid)) {
+ gid = i_gid_into_mnt(mnt_userns, inode);
+ if (in_group_p(gid)) {
found = 1;
if ((pa->e_perm & want) == want)
goto mask;
}
break;
case ACL_GROUP:
- if (in_group_p(pa->e_gid)) {
+ gid = kgid_into_mnt(mnt_userns, pa->e_gid);
+ if (in_group_p(gid)) {
found = 1;
if ((pa->e_perm & want) == want)
goto mask;
@@ -551,8 +558,22 @@ __posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
}
EXPORT_SYMBOL(__posix_acl_chmod);
+/**
+ * posix_acl_chmod - chmod a posix acl
+ *
+ * @mnt_userns: user namespace of the mount @inode was found from
+ * @inode: inode to check permissions on
+ * @mode: the new mode of @inode
+ *
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ */
int
-posix_acl_chmod(struct inode *inode, umode_t mode)
+ posix_acl_chmod(struct user_namespace *mnt_userns, struct inode *inode,
+ umode_t mode)
{
struct posix_acl *acl;
int ret = 0;
@@ -572,7 +593,7 @@ posix_acl_chmod(struct inode *inode, umode_t mode)
ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
if (ret)
return ret;
- ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);
+ ret = inode->i_op->set_acl(mnt_userns, inode, acl, ACL_TYPE_ACCESS);
posix_acl_release(acl);
return ret;
}
@@ -631,9 +652,10 @@ EXPORT_SYMBOL_GPL(posix_acl_create);
/**
* posix_acl_update_mode - update mode in set_acl
- * @inode: target inode
- * @mode_p: mode (pointer) for update
- * @acl: acl pointer
+ * @mnt_userns: user namespace of the mount @inode was found from
+ * @inode: target inode
+ * @mode_p: mode (pointer) for update
+ * @acl: acl pointer
*
* Update the file mode when setting an ACL: compute the new file permission
* bits based on the ACL. In addition, if the ACL is equivalent to the new
@@ -642,9 +664,16 @@ EXPORT_SYMBOL_GPL(posix_acl_create);
* As with chmod, clear the setgid bit if the caller is not in the owning group
* or capable of CAP_FSETID (see inode_change_ok).
*
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ *
* Called from set_acl inode operations.
*/
-int posix_acl_update_mode(struct inode *inode, umode_t *mode_p,
+int posix_acl_update_mode(struct user_namespace *mnt_userns,
+ struct inode *inode, umode_t *mode_p,
struct posix_acl **acl)
{
umode_t mode = inode->i_mode;
@@ -655,8 +684,8 @@ int posix_acl_update_mode(struct inode *inode, umode_t *mode_p,
return error;
if (error == 0)
*acl = NULL;
- if (!in_group_p(inode->i_gid) &&
- !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+ if (!in_group_p(i_gid_into_mnt(mnt_userns, inode)) &&
+ !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID))
mode &= ~S_ISGID;
*mode_p = mode;
return 0;
@@ -668,7 +697,8 @@ EXPORT_SYMBOL(posix_acl_update_mode);
*/
static void posix_acl_fix_xattr_userns(
struct user_namespace *to, struct user_namespace *from,
- void *value, size_t size)
+ struct user_namespace *mnt_userns,
+ void *value, size_t size, bool from_user)
{
struct posix_acl_xattr_header *header = value;
struct posix_acl_xattr_entry *entry = (void *)(header + 1), *end;
@@ -693,10 +723,18 @@ static void posix_acl_fix_xattr_userns(
switch(le16_to_cpu(entry->e_tag)) {
case ACL_USER:
uid = make_kuid(from, le32_to_cpu(entry->e_id));
+ if (from_user)
+ uid = kuid_from_mnt(mnt_userns, uid);
+ else
+ uid = kuid_into_mnt(mnt_userns, uid);
entry->e_id = cpu_to_le32(from_kuid(to, uid));
break;
case ACL_GROUP:
gid = make_kgid(from, le32_to_cpu(entry->e_id));
+ if (from_user)
+ gid = kgid_from_mnt(mnt_userns, gid);
+ else
+ gid = kgid_into_mnt(mnt_userns, gid);
entry->e_id = cpu_to_le32(from_kgid(to, gid));
break;
default:
@@ -705,20 +743,24 @@ static void posix_acl_fix_xattr_userns(
}
}
-void posix_acl_fix_xattr_from_user(void *value, size_t size)
+void posix_acl_fix_xattr_from_user(struct user_namespace *mnt_userns,
+ void *value, size_t size)
{
struct user_namespace *user_ns = current_user_ns();
- if (user_ns == &init_user_ns)
+ if ((user_ns == &init_user_ns) && (mnt_userns == &init_user_ns))
return;
- posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
+ posix_acl_fix_xattr_userns(&init_user_ns, user_ns, mnt_userns, value,
+ size, true);
}
-void posix_acl_fix_xattr_to_user(void *value, size_t size)
+void posix_acl_fix_xattr_to_user(struct user_namespace *mnt_userns,
+ void *value, size_t size)
{
struct user_namespace *user_ns = current_user_ns();
- if (user_ns == &init_user_ns)
+ if ((user_ns == &init_user_ns) && (mnt_userns == &init_user_ns))
return;
- posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
+ posix_acl_fix_xattr_userns(user_ns, &init_user_ns, mnt_userns, value,
+ size, false);
}
/*
@@ -858,7 +900,8 @@ posix_acl_xattr_get(const struct xattr_handler *handler,
}
int
-set_posix_acl(struct inode *inode, int type, struct posix_acl *acl)
+set_posix_acl(struct user_namespace *mnt_userns, struct inode *inode,
+ int type, struct posix_acl *acl)
{
if (!IS_POSIXACL(inode))
return -EOPNOTSUPP;
@@ -867,7 +910,7 @@ set_posix_acl(struct inode *inode, int type, struct posix_acl *acl)
if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
return acl ? -EACCES : 0;
- if (!inode_owner_or_capable(inode))
+ if (!inode_owner_or_capable(mnt_userns, inode))
return -EPERM;
if (acl) {
@@ -875,15 +918,16 @@ set_posix_acl(struct inode *inode, int type, struct posix_acl *acl)
if (ret)
return ret;
}
- return inode->i_op->set_acl(inode, acl, type);
+ return inode->i_op->set_acl(mnt_userns, inode, acl, type);
}
EXPORT_SYMBOL(set_posix_acl);
static int
posix_acl_xattr_set(const struct xattr_handler *handler,
- struct dentry *unused, struct inode *inode,
- const char *name, const void *value,
- size_t size, int flags)
+ struct user_namespace *mnt_userns,
+ struct dentry *unused, struct inode *inode,
+ const char *name, const void *value, size_t size,
+ int flags)
{
struct posix_acl *acl = NULL;
int ret;
@@ -893,7 +937,7 @@ posix_acl_xattr_set(const struct xattr_handler *handler,
if (IS_ERR(acl))
return PTR_ERR(acl);
}
- ret = set_posix_acl(inode, handler->flags, acl);
+ ret = set_posix_acl(mnt_userns, inode, handler->flags, acl);
posix_acl_release(acl);
return ret;
}
@@ -922,12 +966,13 @@ const struct xattr_handler posix_acl_default_xattr_handler = {
};
EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
-int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+int simple_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
+ struct posix_acl *acl, int type)
{
int error;
if (type == ACL_TYPE_ACCESS) {
- error = posix_acl_update_mode(inode,
+ error = posix_acl_update_mode(mnt_userns, inode,
&inode->i_mode, &acl);
if (error)
return error;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 04:55:56 +0100