Re: [PATCH 0/2] open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE

[Christian Brauner <brauner@kernel.org>]

On Fri, 08 Aug 2025 03:55:04 +1000, Aleksa Sarai wrote:
> As described in commit 7a54947e727b ('Merge patch series "fs: allow
> changing idmappings"'), open_tree_attr(2) was necessary in order to
> allow for a detached mount to be created and have its idmappings changed
> without the risk of any racing threads operating on it. For this reason,
> mount_setattr(2) still does not allow for id-mappings to be changed.
> 
> However, there was a bug in commit 2462651ffa76 ("fs: allow changing
> idmappings") which allowed users to bypass this restriction by calling
> open_tree_attr(2) *without* OPEN_TREE_CLONE.
> 
> [...]

Applied to the vfs.fixes branch of the vfs/vfs.git tree.
Patches in the vfs.fixes branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.fixes

[1/2] open_tree_attr: do not allow id-mapping changes without OPEN_TREE_CLONE
      https://git.kernel.org/vfs/vfs/c/75a7ed5ce861
[2/2] selftests/mount_setattr: add smoke tests for open_tree_attr(2) bug
      https://git.kernel.org/vfs/vfs/c/a597ba0a020b