From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 47B173B42C4; Wed, 9 Sep 2026 23:40:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788997251; cv=none; b=DUx/X0/gvj/OYwlWBbnFSy7QdReI0SAqH8V9wdcq0qh9S/9asU/T0oVmpA+mfGW/UvN07tEzlyP8qI+ErlrWGewl5FCWSn5LC46Be5bicY9pjNSqG3PPmbzLzxDKkzfw57i4Wh8GmGN4WvAea3rExxJ8AGJw/+OsGmlNn3yNQks= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788997251; c=relaxed/simple; bh=Qf7jvpOKbSkQ/rigG4WUFq6Rlwz5ug3NUbrAK/3juwc=; h=Date:To:From:Subject:Message-Id; b=EWpk6ToDNtxaLXS0LjU0V1L01HquS/+Kx4ktb+xFZMBdVkfBqrkWnAKHpX61NLD2mwzjXvl0eUaCRMn6DMCpdP1yaOVMqkcPse73mtD+7IKWRHmMJc6P8FfO4xtcuvX+xfyXWQLXn2RbnoaeoiEd+BDO84ZRMBDs9dDxbPXTwb0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=y2v3oADh; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="y2v3oADh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE7FA1F000FF; Wed, 9 Sep 2026 23:40:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788997250; bh=ctkwBZJ5mcQHj5xauChjKwaTCzWgPiP6EGWZMFhMpzk=; h=Date:To:From:Subject; b=y2v3oADhoBZr/7mnWJW4Ml1cRVlWijcz+K1uoxJoQFfS3LmhLbQWNOkbRSn+wFEXc hfYeKz/9YmlTv0nrM32Q01ay0lG7mQJgurJv/XcepOgpSLBt+xPJa4nHgD752lbV/S jTO5ARkEii2Nw6NUwMhr4eRxAQyu9wh/CJk4EmMI= Date: Wed, 09 Sep 2026 16:40:49 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,vannapurve@google.com,surenb@google.com,stable@vger.kernel.org,si.yanteng@linux.dev,shakeel.butt@linux.dev,rppt@kernel.org,roman.gushchin@linux.dev,rientjes@google.com,peterx@redhat.com,osalvador@suse.de,nphamcs@gmail.com,muchun.song@linux.dev,mhocko@kernel.org,mawupeng1@huawei.com,louhongxiang@huawei.com,ljs@kernel.org,linmiaohe@huawei.com,liam@infradead.org,jthoughton@google.com,joshua.hahnjy@gmail.com,hannes@cmpxchg.org,fvdl@google.com,dzm91@hust.edu.cn,david@kernel.org,corbet@lwn.net,alexs@kernel.org,ackerleytng@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hugetlb-drop-refcount-before-freeing-on-memcg-charge-failure.patch added to mm-unstable branch Message-Id: <20260909234049.DE7FA1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: hugetlb: drop refcount before freeing on memcg charge failure has been added to the -mm mm-unstable branch. Its filename is mm-hugetlb-drop-refcount-before-freeing-on-memcg-charge-failure.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-drop-refcount-before-freeing-on-memcg-charge-failure.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: Ackerley Tng Subject: mm: hugetlb: drop refcount before freeing on memcg charge failure Date: Wed, 09 Sep 2026 10:11:01 -0700 When mem_cgroup_charge_hugetlb(folio, gfp) returns -ENOMEM, the folio has its refcount set to 1 via folio_ref_unfreeze(folio, 1). The error path calls free_huge_folio(folio) directly, which expects a refcount of 0. Hence, VM_BUG_ON_FOLIO(folio_ref_count(folio), folio) is triggered. Even with CONFIG_DEBUG_VM disabled, returning a folio with refcount 1 to the freelist can corrupt allocator state later. Use folio_put(folio) instead of free_huge_folio(folio) to properly drop the reference before freeing it. Link: https://lore.kernel.org/20260909-hugetlb-alloc-folio-memcg-charge-error-handling-v2-2-4b4a8a19a7f7@google.com Fixes: 991135774c0e0 ("memcg/hugetlb: introduce mem_cgroup_charge_hugetlb") Signed-off-by: Ackerley Tng Reviewed-by: Muchun Song Reviewed-by: Joshua Hahn Cc: Alex Shi Cc: David Hildenbrand Cc: David Rientjes Cc: Dongliang Mu Cc: Frank van der Linden Cc: Hongxiang Lou Cc: James Houghton Cc: Johannes Weiner Cc: Jonathan Corbet Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Ma Wupeng Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Nhat Pham Cc: Oscar Salvador Cc: Peter Xu Cc: Roman Gushchin Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vishal Annapurve Cc: Vlastimil Babka Cc: Yanteng Si Cc: Signed-off-by: Andrew Morton --- mm/hugetlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/hugetlb.c~mm-hugetlb-drop-refcount-before-freeing-on-memcg-charge-failure +++ a/mm/hugetlb.c @@ -2917,7 +2917,7 @@ struct folio *hugetlb_alloc_folio(struct lruvec_stat_mod_folio(folio, NR_HUGETLB, nr_pages); if (ret == -ENOMEM) { - free_huge_folio(folio); + folio_put(folio); /* * Skip uncharging hugetlb_cgroup since the charges * were committed to the folio and freeing the folio _ Patches currently in -mm which might be from ackerleytng@google.com are mm-hugetlb-return-enospc-on-memcg-charge-failure.patch mm-hugetlb-drop-refcount-before-freeing-on-memcg-charge-failure.patch