c878bea3c9
The EXT4_FC_REPLAY bit in sbi->s_mount_state is used to indicate that
we are in the middle of replay the fast commit journal. This was
actually a mistake, since the sbi->s_mount_info is initialized from
es->s_state. Arguably s_mount_state is misleadingly named, but the
name is historical --- s_mount_state and s_state dates back to ext2.
What should have been used is the ext4_{set,clear,test}_mount_flag()
inline functions, which sets EXT4_MF_* bits in sbi->s_mount_flags.
The problem with using EXT4_FC_REPLAY is that a maliciously corrupted
superblock could result in EXT4_FC_REPLAY getting set in
s_mount_state. This bypasses some sanity checks, and this can trigger
a BUG() in ext4_es_cache_extent(). As a easy-to-backport-fix, filter
out the EXT4_FC_REPLAY bit for now. We should eventually transition
away from EXT4_FC_REPLAY to something like EXT4_MF_REPLAY.
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20220420192312.1655305-1-phind.uet@gmail.com
Link: https://lore.kernel.org/r/20220517174028.942119-1-tytso@mit.edu
Reported-by: syzbot+c7358a3cd05ee786eb31@syzkaller.appspotmail.com
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.