Hi Andrew,
On 12/15/2023 3:41 AM, Andrew Morton wrote:
> Large folios occupy N consecutive entries in the swap cache instead of
> using multi-index entries like the page cache. However, if a large folio
> is re-added to the LRU list, it can be migrated. The migration code was
> not aware of the difference between the swap cache and the page cache and
> assumed that a single xas_store() would be sufficient.
>
> This leaves potentially many stale pointers to the now-migrated folio in
> the swap cache, which can lead to almost arbitrary data corruption in the
> future. This can also manifest as infinite loops with the RCU read lock
> held.
>
> [willy@xxxxxxxxxxxxx: modifications to the changelog & tweaked the fix]
> Fixes: 3417013e0d183be ("mm/migrate: Add folio_migrate_mapping()")
> Link: https://lkml.kernel.org/r/20231214045841.961776-1-willy@xxxxxxxxxxxxx
> Signed-off-by: Charan Teja Kalla <quic_charante@xxxxxxxxxxx>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Reported-by: Charan Teja Kalla <quic_charante@xxxxxxxxxxx>
> Closes: https://lkml.kernel.org/r/1700569840-17327-1-git-send-email-quic_charante@xxxxxxxxxxx
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Errors were reported from checkpatch.pl.
1) Seems we have used 15chars of sha1.
2) space before Closes:
Summary:
WARNING:BAD_FIXES_TAG: Please use correct Fixes: style 'Fixes: <12 chars
of sha1> ("<title line>")' - ie: 'Fixes: 3417013e0d18 ("mm/migrate: Add
folio_migrate_mapping()")'
#21:
--
WARNING:BAD_REPORTED_BY_LINK: Reported-by: should be immediately
followed by Closes: with a URL to the report
#26:
