+ mm-mempolicy-fix-memory-leak-in-weighted_interleave_auto_store.patch added to mm-unstable branch

+ mm-mempolicy-fix-memory-leak-in-weighted_interleave_auto_store.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/mempolicy: fix memory leak in weighted_interleave_auto_store()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mempolicy-fix-memory-leak-in-weighted_interleave_auto_store.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mempolicy-fix-memory-leak-in-weighted_interleave_auto_store.patch

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days

------------------------------------------------------
From: Jackie Liu <liuyun01@kylinos.cn>
Subject: mm/mempolicy: fix memory leak in weighted_interleave_auto_store()
Date: Tue, 31 Mar 2026 18:07:40 +0800

Add the missing kfree(new_wi_state) when the auto mode is already set to
the requested value.  When a user writes "false" to the auto sysfs
interface and the current mode is already manual (mode_auto == false), the
function returns early without freeing new_wi_state allocated at the
beginning of the function.  This can be triggered repeatedly from
userspace, leaking memory on each write.

Link: https://lkml.kernel.org/r/20260331100740.84906-1-liu.yun@linux.dev
Fixes: e341f9c3c841 ("mm/mempolicy: Weighted Interleave Auto-tuning")
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Reviewed by: Donet Tom <donettom@linux.ibm.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mempolicy.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/mempolicy.c~mm-mempolicy-fix-memory-leak-in-weighted_interleave_auto_store
+++ a/mm/mempolicy.c
@@ -3707,6 +3707,7 @@ static ssize_t weighted_interleave_auto_
 			goto update_wi_state;
 		if (input == old_wi_state->mode_auto) {
 			mutex_unlock(&wi_state_lock);
+			kfree(new_wi_state);
 			return count;
 		}
 
_

Patches currently in -mm which might be from liuyun01@kylinos.cn are

mm-mempolicy-fix-memory-leak-in-weighted_interleave_auto_store.patch