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.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H7.8/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H