mirror of
https://github.com/torvalds/linux.git
synced 2026-08-02 05:12:01 +02:00
Linux kernel source tree
edd8276dd7
The AGF verifier does not check that the AGF length field is within known good bounds. This has never been checked by runtime kernel code (i.e. the lack of verification goes back to 1993) yet we assume in many places that it is correct and verify other metdata against it. Add length verification to the AGF verifier. The length of the AGF must be equal to the size of the AG specified in the superblock, unless it is the last AG in the filesystem. In that case, it must be less than or equal to sb->sb_agblocks and greater than XFS_MIN_AG_BLOCKS, which is the smallest AG a growfs operation will allow to exist. This requires a bit of rework of the verifier function. We want to verify metadata before we use it to verify other metadata. Hence we need to verify the AGF sequence numbers before using them to verify the length of the AGF. Then we can verify the AGF length before we verify AGFL fields. Then we can verifier other fields that are bounds limited by the AGF length. And, finally, by calculating agf_length only once into a local variable, we can collapse repeated "if (xfs_has_foo() &&" conditionaly checks into single checks. This makes the code much easier to follow as all the checks for a given feature are obviously in the same place. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.