diff options
| -rw-r--r-- | fs/overlayfs/dir.c | 1 | ||||
| -rw-r--r-- | fs/overlayfs/inode.c | 94 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 17 |
3 files changed, 112 insertions, 0 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index eb49d5d7b56f..0e817ebce92c 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -1313,6 +1313,7 @@ const struct inode_operations ovl_dir_inode_operations = { .listxattr = ovl_listxattr, .get_inode_acl = ovl_get_inode_acl, .get_acl = ovl_get_acl, + .set_acl = ovl_set_acl, .update_time = ovl_update_time, .fileattr_get = ovl_fileattr_get, .fileattr_set = ovl_fileattr_set, diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 74edbd1c1159..304a6dbb852a 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -592,6 +592,98 @@ struct posix_acl *do_ovl_get_acl(struct user_namespace *mnt_userns, return acl; } + +static int ovl_set_or_remove_acl(struct dentry *dentry, struct inode *inode, + struct posix_acl *acl, int type) +{ + int err; + struct path realpath; + const char *acl_name; + const struct cred *old_cred; + struct ovl_fs *ofs = OVL_FS(dentry->d_sb); + struct dentry *upperdentry = ovl_dentry_upper(dentry); + struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry); + + err = ovl_want_write(dentry); + if (err) + return err; + + /* + * If ACL is to be removed from a lower file, check if it exists in + * the first place before copying it up. + */ + acl_name = posix_acl_xattr_name(type); + if (!acl && !upperdentry) { + struct posix_acl *real_acl; + + ovl_path_lower(dentry, &realpath); + old_cred = ovl_override_creds(dentry->d_sb); + real_acl = vfs_get_acl(mnt_user_ns(realpath.mnt), realdentry, + acl_name); + revert_creds(old_cred); + posix_acl_release(real_acl); + if (IS_ERR(real_acl)) { + err = PTR_ERR(real_acl); + goto out_drop_write; + } + } + + if (!upperdentry) { + err = ovl_copy_up(dentry); + if (err) + goto out_drop_write; + + realdentry = ovl_dentry_upper(dentry); + } + + old_cred = ovl_override_creds(dentry->d_sb); + if (acl) + err = ovl_do_set_acl(ofs, realdentry, acl_name, acl); + else + err = ovl_do_remove_acl(ofs, realdentry, acl_name); + revert_creds(old_cred); + + /* copy c/mtime */ + ovl_copyattr(inode); + +out_drop_write: + ovl_drop_write(dentry); + return err; +} + +int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, + struct posix_acl *acl, int type) +{ + int err; + struct inode *inode = d_inode(dentry); + struct dentry *workdir = ovl_workdir(dentry); + struct inode *realinode = ovl_inode_real(inode); + + if (!IS_POSIXACL(d_inode(workdir))) + return -EOPNOTSUPP; + if (!realinode->i_op->set_acl) + return -EOPNOTSUPP; + if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) + return acl ? -EACCES : 0; + if (!inode_owner_or_capable(&init_user_ns, inode)) + return -EPERM; + + /* + * Check if sgid bit needs to be cleared (actual setacl operation will + * be done with mounter's capabilities and so that won't do it for us). + */ + if (unlikely(inode->i_mode & S_ISGID) && type == ACL_TYPE_ACCESS && + !in_group_p(inode->i_gid) && + !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID)) { + struct iattr iattr = { .ia_valid = ATTR_KILL_SGID }; + + err = ovl_setattr(&init_user_ns, dentry, &iattr); + if (err) + return err; + } + + return ovl_set_or_remove_acl(dentry, inode, acl, type); +} #endif int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags) @@ -768,6 +860,7 @@ static const struct inode_operations ovl_file_inode_operations = { .listxattr = ovl_listxattr, .get_inode_acl = ovl_get_inode_acl, .get_acl = ovl_get_acl, + .set_acl = ovl_set_acl, .update_time = ovl_update_time, .fiemap = ovl_fiemap, .fileattr_get = ovl_fileattr_get, @@ -789,6 +882,7 @@ static const struct inode_operations ovl_special_inode_operations = { .listxattr = ovl_listxattr, .get_inode_acl = ovl_get_inode_acl, .get_acl = ovl_get_acl, + .set_acl = ovl_set_acl, .update_time = ovl_update_time, }; diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index d334977030c8..ab5061c9aa2a 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -8,6 +8,8 @@ #include <linux/uuid.h> #include <linux/fs.h> #include <linux/namei.h> +#include <linux/posix_acl.h> +#include <linux/posix_acl_xattr.h> #include "ovl_entry.h" #undef pr_fmt @@ -278,6 +280,18 @@ static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); } +static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, + const char *acl_name, struct posix_acl *acl) +{ + return vfs_set_acl(ovl_upper_mnt_userns(ofs), dentry, acl_name, acl); +} + +static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, + const char *acl_name) +{ + return vfs_remove_acl(ovl_upper_mnt_userns(ofs), dentry, acl_name); +} + static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, struct dentry *olddentry, struct inode *newdir, struct dentry *newdentry, unsigned int flags) @@ -607,9 +621,12 @@ static inline struct posix_acl *ovl_get_acl(struct user_namespace *mnt_userns, { return do_ovl_get_acl(mnt_userns, d_inode(dentry), type, false, false); } +int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, + struct posix_acl *acl, int type); #else #define ovl_get_inode_acl NULL #define ovl_get_acl NULL +#define ovl_set_acl NULL #endif int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags); |