From 643fe55a0679ae5582a1a2a1df86dc240292cd1b Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 21 Jan 2021 14:19:34 +0100 Subject: open: handle idmapped mounts in do_truncate() When truncating files the vfs will verify that the caller is privileged over the inode. Extend it to handle idmapped mounts. If the inode is accessed through an idmapped mount it is mapped according to the mount's user namespace. Afterwards the permissions checks are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-16-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner --- fs/namei.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/namei.c') diff --git a/fs/namei.c b/fs/namei.c index 5c9f6f8e90c4..c8c083daf368 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3009,7 +3009,7 @@ static int handle_truncate(struct file *filp) if (!error) error = security_path_truncate(path); if (!error) { - error = do_truncate(path->dentry, 0, + error = do_truncate(&init_user_ns, path->dentry, 0, ATTR_MTIME|ATTR_CTIME|ATTR_OPEN, filp); } -- cgit v1.2.3