39049b69ec
The new Merkle tree construction algorithm is a bit fragile in that it
may overflow the 'root_hash' array if the tree actually generated does
not match the calculated tree parameters.
This should never happen unless there is a filesystem bug that allows
the file size to change despite deny_write_access(), or a bug in the
Merkle tree logic itself. Regardless, it's fairly easy to check for
buffer overflow here, so let's do so.
This is a robustness improvement only; this case is not currently known
to be reachable. I've added a Fixes tag anyway, since I recommend that
this be included in kernels that have the mentioned commit.
Fixes: 56124d6c87 ("fsverity: support enabling with tree block size < PAGE_SIZE")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230328041505.110162-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
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 Restructured Text 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.