Amir Goldstein a1e0eb8f55 ovl: check access to copy_file_range source with src mounter creds ... Commit 5dae222a5f ("vfs: allow copy_file_range to copy across devices") allowed filesystems that implement the copy_file_range() f_op to decide if they want to access cross-sb copy from/to the same fs type. The same commit added checks to verify same sb copy for filesystems that implement ->copy_file_range() and do not support cross-sb copy at the time, namely, to ceph, fuse and nfs. The two remaining fs which implement ->copy_file_range(), cifs and overlayfs started to support cross-sb copy from this time. While overlayfs does support cross-sb copy when the two underlying files are on the same base fs, the copy operation on the two real files from two different overalyfs filesystems is performed with the mounter creds of the destination overlayfs and the read permission access hook for the source file was called with the wrong creds. This could cause either deny of access to copy which would otherwise be allowed (e.g. with splice) or allow read access to file which would otherwise be denied. Fix the latter case by explicitly verifying read access to source file with the source overlayfs mounter creds. The former case remains a quirk of cross-sb overlayfs copy, but userspace could fall back to regular copy so no harm done. Fixes: 5dae222a5f ("vfs: allow copy_file_range to copy across devices") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://patch.msgid.link/20260712122421.203113-1-amir73il@gmail.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>		2026-07-22 16:42:28 +02:00
..
copy_up.c	ovl: use linked upper dentry in copy-up tmpfile	2026-07-01 15:26:24 +02:00
dir.c	Fixing livelocks in shrink_dcache_tree()	2026-04-21 07:30:44 -07:00
export.c	vfs-7.1-rc1.kino	2026-04-13 12:19:01 -07:00
file.c	ovl: check access to copy_file_range source with src mounter creds	2026-07-22 16:42:28 +02:00
inode.c	ovl: fix comment about locking order	2026-07-01 15:26:25 +02:00
Kconfig	fs: prepare for stackable filesystems backing file helpers	2023-12-23 16:35:08 +02:00
Makefile	ovl: Move xattr support to new xattrs.c file	2023-10-31 00:12:59 +02:00
namei.c	treewide: change inode->i_ino from unsigned long to u64	2026-03-06 14:31:28 +01:00
overlayfs.h	vfs-7.1-rc1.directory	2026-04-13 10:24:33 -07:00
ovl_entry.h	ovl: make fsync after metadata copy-up opt-in mount option	2026-03-27 12:48:10 +01:00
params.c	ovl: make fsync after metadata copy-up opt-in mount option	2026-03-27 12:48:10 +01:00
params.h	ovl: Prepare for mounting case-insensitive enabled layers	2025-09-23 12:29:35 +02:00
readdir.c	ovl: keep err zero after successful ovl_cache_get()	2026-05-18 14:56:15 +02:00
super.c	vfs-7.1-rc1.directory	2026-04-13 10:24:33 -07:00
util.c	ovl: fix verity lazy-load guard broken by fsverity_active() semantic change	2026-05-06 08:37:30 -07:00
xattrs.c	ovl: fix trusted xattr escape prefix matching	2026-07-22 13:48:00 +02:00