1
0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-01-12 01:20:14 +00:00
Wei Yang cff47b9e39 mm/huge_memory: fix NULL pointer deference when splitting folio
Commit c010d47f107f ("mm: thp: split huge page to any lower order pages")
introduced an early check on the folio's order via mapping->flags before
proceeding with the split work.

This check introduced a bug: for shmem folios in the swap cache and
truncated folios, the mapping pointer can be NULL.  Accessing
mapping->flags in this state leads directly to a NULL pointer dereference.

This commit fixes the issue by moving the check for mapping != NULL before
any attempt to access mapping->flags.

Link: https://lkml.kernel.org/r/20251119235302.24773-1-richard.weiyang@gmail.com
Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
2025-10-31 12:57:19 -07:00
2025-11-07 08:10:55 -08:00
2025-11-09 09:29:44 -08:00
2025-10-04 11:13:11 -07:00
2025-09-29 11:20:29 -07:00
2025-11-15 10:52:01 -08:00
2025-10-05 10:48:33 -07:00
2025-10-30 13:08:08 +01:00
2025-10-18 10:25:43 +02:00
2025-11-24 14:25:17 -08:00
2025-02-19 14:53:27 -07:00
2025-11-09 15:10:19 -08:00
2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Languages
C 97.1%
Assembly 1%
Shell 0.6%
Rust 0.4%
Python 0.4%
Other 0.3%