65f8ea4cd5
Currently ext4 directory handling code implicitly assumes that the directory blocks are always within the i_size. In fact ext4_append() will attempt to allocate next directory block based solely on i_size and the i_size is then appropriately increased after a successful allocation. However, for this to work it requires i_size to be correct. If, for any reason, the directory inode i_size is corrupted in a way that the directory tree refers to a valid directory block past i_size, we could end up corrupting parts of the directory tree structure by overwriting already used directory blocks when modifying the directory. Fix it by catching the corruption early in __ext4_read_dirblock(). Addresses Red-Hat-Bugzilla: #2070205 CVE: CVE-2022-1184 Signed-off-by: Lukas Czerner <lczerner@redhat.com> Cc: stable@vger.kernel.org Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/20220704142721.157985-1-lczerner@redhat.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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.