Patch "ovl: remove privs in ovl_copyfile()" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ovl: remove privs in ovl_copyfile()

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ovl-remove-privs-in-ovl_copyfile.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4030cb20eb55c8012c42ed242cd545ac998950e8
Author: Amir Goldstein <amir73il@xxxxxxxxx>
Date:   Mon Oct 17 17:06:38 2022 +0200

    ovl: remove privs in ovl_copyfile()
    
    [ Upstream commit b306e90ffabdaa7e3b3350dbcd19b7663e71ab17 ]
    
    Underlying fs doesn't remove privs because copy_range/remap_range are
    called with privileged mounter credentials.
    
    This fixes some failures in fstest generic/673.
    
    Fixes: 8ede205541ff ("ovl: add reflink/copyfile/dedup support")
    Acked-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
    Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
    Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index a1a22f58ba18..755a11c63596 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -567,14 +567,23 @@ static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
 	const struct cred *old_cred;
 	loff_t ret;
 
+	inode_lock(inode_out);
+	if (op != OVL_DEDUPE) {
+		/* Update mode */
+		ovl_copyattr(inode_out);
+		ret = file_remove_privs(file_out);
+		if (ret)
+			goto out_unlock;
+	}
+
 	ret = ovl_real_fdget(file_out, &real_out);
 	if (ret)
-		return ret;
+		goto out_unlock;
 
 	ret = ovl_real_fdget(file_in, &real_in);
 	if (ret) {
 		fdput(real_out);
-		return ret;
+		goto out_unlock;
 	}
 
 	old_cred = ovl_override_creds(file_inode(file_out)->i_sb);
@@ -603,6 +612,9 @@ static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
 	fdput(real_in);
 	fdput(real_out);
 
+out_unlock:
+	inode_unlock(inode_out);
+
 	return ret;
 }