mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-14 02:59:19 -04:00
9308366f06
As described in commit7a54947e72('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 commit2462651ffa("fs: allow changing idmappings") which allowed users to bypass this restriction by calling open_tree_attr(2) *without* OPEN_TREE_CLONE. can_idmap_mount() prevented this bug from allowing an attached mountpoint's id-mapping from being modified (thanks to an is_anon_ns() check), but this still allows for detached (but visible) mounts to have their be id-mapping changed. This risks the same UAF and locking issues as described in the merge commit, and was likely unintentional. Fixes:2462651ffa("fs: allow changing idmappings") Cc: stable@vger.kernel.org # v6.15+ Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Link: https://lore.kernel.org/20250808-open_tree_attr-bugfix-idmap-v1-1-0ec7bc05646c@cyphar.com Signed-off-by: Christian Brauner <brauner@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.