fuse: Propagate dentry down to inode_change_ok()

[ Upstream commit 62490330 ]

To avoid clearing of capabilities or security related extended
attributes too early, inode_change_ok() will need to take dentry instead
of inode. Propagate it down to fuse_do_setattr().

References: CVE-2015-1350
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

Conflicts: Missing file_dentry() from d101a125Signed-off-by: Philipp Hahn <hahn@univention.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

fs/fuse/dir.c

@@ -1602,9 +1602,10 @@ int fuse_flush_times(struct inode *inode, struct fuse_file *ff)
  * vmtruncate() doesn't allow for this case, so do the rlimit checking
  * and the actual truncation by hand.
  */
-int fuse_do_setattr(struct inode *inode, struct iattr *attr,
+int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 		    struct file *file)
 {
+	struct inode *inode = d_inode(dentry);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_inode *fi = get_fuse_inode(inode);
 	FUSE_ARGS(args);
@@ -1718,9 +1719,9 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr)
 		return -EACCES;
 
 	if (attr->ia_valid & ATTR_FILE)
-		return fuse_do_setattr(inode, attr, attr->ia_file);
+		return fuse_do_setattr(entry, attr, attr->ia_file);
 	else
-		return fuse_do_setattr(inode, attr, NULL);
+		return fuse_do_setattr(entry, attr, NULL);
 }
 
 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,

fs/fuse/file.c

@@ -2797,7 +2797,7 @@ static void fuse_do_truncate(struct file *file)
 	attr.ia_file = file;
 	attr.ia_valid |= ATTR_FILE;
 
-	fuse_do_setattr(inode, &attr, file);
+	fuse_do_setattr(file->f_path.dentry, &attr, file);
 }
 
 static inline loff_t fuse_round_up(loff_t off)

fs/fuse/fuse_i.h

@@ -913,7 +913,7 @@ bool fuse_write_update_size(struct inode *inode, loff_t pos);
 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 
-int fuse_do_setattr(struct inode *inode, struct iattr *attr,
+int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 		    struct file *file);
 
 void fuse_set_initialized(struct fuse_conn *fc);