nilfs2: fix kernel bug due to missing clearing of checked flag

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix kernel bug due to missing clearing of checked flag Syzbot reported that in directory operations after nilfs2 detects filesystem corruption and degrades to read-only, __block_write_begin_int(), which is called to prepare block writes, may fail the BUG_ON check for accesses exceeding the folio/page size, triggering a kernel bug. This was found to be because the "checked" flag of a page/folio was not cleared when it was discarded by nilfs2's own routine, which causes the sanity check of directory entries to be skipped when the directory page/folio is reloaded. So, fix that. This was necessary when the use of nilfs2's own page discard routine was applied to more than just metadata files.

References

• https://git.kernel.org/stable/c/994b2fa13a6c9cf3feca93090a9c337d48e3d60d
• https://git.kernel.org/stable/c/64afad73e4623308d8943645e5631f2c7a2d7971
• https://git.kernel.org/stable/c/aa0cee46c5d3fd9a39575a4c8a4f65f25f095b89
• https://git.kernel.org/stable/c/f05dbebb8ee34882505d53d83af7d18f28a49248
• https://git.kernel.org/stable/c/cd0cdb51b15203fa27d4b714be83b7dfffa0b752
• https://git.kernel.org/stable/c/f2f1fa446676c21edb777e6d2bc4fa8f956fab68
• https://git.kernel.org/stable/c/56c6171932a7fb267ac6cb4ff8759b93ee1d0e2e
• https://git.kernel.org/stable/c/41e192ad2779cae0102879612dfe46726e4396aa