CVE-2023-53337

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> nilfs2: do not write dirty data after degenerating to read-only<br /> <br /> According to syzbot&amp;#39;s report, mark_buffer_dirty() called from<br /> nilfs_segctor_do_construct() outputs a warning with some patterns after<br /> nilfs2 detects metadata corruption and degrades to read-only mode.<br /> <br /> After such read-only degeneration, page cache data may be cleared through<br /> nilfs_clear_dirty_page() which may also clear the uptodate flag for their<br /> buffer heads. However, even after the degeneration, log writes are still<br /> performed by unmount processing etc., which causes mark_buffer_dirty() to<br /> be called for buffer heads without the "uptodate" flag and causes the<br /> warning.<br /> <br /> Since any writes should not be done to a read-only file system in the<br /> first place, this fixes the warning in mark_buffer_dirty() by letting<br /> nilfs_segctor_do_construct() abort early if in read-only mode.<br /> <br /> This also changes the retry check of nilfs_segctor_write_out() to avoid<br /> unnecessary log write retries if it detects -EROFS that<br /> nilfs_segctor_do_construct() returned.