Description: mm: Opening THP-backed special file for write causes crash in block_invalidatepage()
References:
 https://bugzilla.redhat.com/show_bug.cgi?id=2026487
 https://lkml.org/lkml/2021/9/17/1037
 https://lkml.org/lkml/2021/9/12/323
 https://lore.kernel.org/linux-mm/a07564a3-b2fc-9ffe-3ace-3f276075ea5c@google.com/
 https://lore.kernel.org/lkml/CACkBjsYwLYLRmX8GpsDpMthagWOjWWrNxqY6ZLNQVr6yx+f5vA@mail.gmail.com/
Notes:
 bwh> Introduced in 5.4 by commit 99cb0dbd47a1 "mm,thp: add read-only THP
 bwh> support for (non-shmem) FS".
Bugs:
upstream: released (5.15) [a4aeaa06d45e90f9b279f0b09de84bd00006e733]
5.10-upstream-stable: released (5.10.78) [6d67b2a73b8e3a079c355bab3c1aef7d85a044b8]
4.19-upstream-stable: N/A "Vulnerable code not present"
4.9-upstream-stable: N/A "Vulnerable code not present"
sid: released (5.14.16-1)
5.10-bullseye-security: released (5.10.84-1)
4.19-buster-security: N/A "Vulnerable code not present"
4.9-stretch-security: N/A "Vulnerable code not present"