+ mm-kmemleak-serialize-disable-time-cleanup.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: kmemleak: serialize disable-time cleanup
has been added to the -mm mm-new branch.  Its filename is
     mm-kmemleak-serialize-disable-time-cleanup.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-kmemleak-serialize-disable-time-cleanup.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Weilin Tong <tongweilin@linux.alibaba.com>
Subject: mm: kmemleak: serialize disable-time cleanup
Date: Thu,  5 Nov 2026 17:52:49 +0800

kmemleak_do_cleanup() drops scan_mutex before removing tracked objects
without kmemleak_lock.  A concurrent clear command can therefore start
another cleanup while the background cleanup is still running.

Keep scan_mutex held until the background cleanup completes, serializing
its lockless removals with explicit clearing and report readers.

Link: https://lore.kernel.org/149d93f2cfe20d355f4d9882ce2bf99030217772.1793871596.git.tongweilin@linux.alibaba.com
Fixes: 2abd839aa7e6 ("kmemleak: Do not corrupt the object_list during clean-up")
Signed-off-by: Weilin Tong <tongweilin@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---

 mm/kmemleak.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/mm/kmemleak.c~mm-kmemleak-serialize-disable-time-cleanup
+++ a/mm/kmemleak.c
@@ -2532,12 +2532,13 @@ static void kmemleak_do_cleanup(struct w
 	 * function.
 	 */
 	kmemleak_free_enabled = 0;
-	mutex_unlock(&scan_mutex);
 
+	/* Serialize the lockless cleanup with report readers. */
 	if (!kmemleak_found_leaks)
 		__kmemleak_do_cleanup();
 	else
 		pr_info("Kmemleak disabled without freeing internal data. Reclaim the memory with \"echo clear > /sys/kernel/debug/kmemleak\".\n");
+	mutex_unlock(&scan_mutex);
 }
 
 static DECLARE_WORK(cleanup_work, kmemleak_do_cleanup);
_

Patches currently in -mm which might be from tongweilin@linux.alibaba.com are

tools-mm-thpmaps-fix-partial-thp-anon-file-accounting.patch
tools-mm-thpmaps-fix-missing-order-1-file-thp-statistics.patch
tools-mm-thpmaps-fix-missing-mapping-names.patch
mm-kmemleak-serialize-disable-time-cleanup.patch
tools-mm-thpmaps-handle-carriage-returns-and-non-utf-8-filenames.patch