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 857C7125A0 for ; Wed, 30 Sep 2026 00:04:03 +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=1790726644; cv=none; b=hqSLSQBKOyGdcKfFwX5PGKD1aW/8OUgOb0lizxUNeodRHsJeJH44V1mms5fLCZu+rKLnCK25usSa08d29NlfbU5wYFHruIUNVW4/YNwn7AP8THusMHTmxjnbxH0fbu8QceD02kDrhymfC3esk6ts4ZZEQmZZZKC5X8rNpx3F8gw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790726644; c=relaxed/simple; bh=+EtPrwGh917kW/U83niSsKt7jNNxkC3hpOcroybv6Ns=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a3tLmIH6DiFdIIq+ZAWlnZMrBq641IQZXftlJcuSQYpsH8NgR+9d1Cy/lyATGFU/bU+mf3VjkbOlPDhkzhxHvlP24kWNxqAeEdZ2STxURE7n507PtZaqEDlEvOmQfdI1lK24D7A4bgRhg7PkCUyM4cJ8yJXIRnYtoGo6jK/qCic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mSYwWcBE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mSYwWcBE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78EA71F000FF; Wed, 30 Sep 2026 00:04:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790726643; bh=2LnV8ST5oDdKfL8R/6xaK6OM4DtpFrHwoMDuMQkS9jg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mSYwWcBEeTJ3bzV/L3ezT25t6Y4Bv1flGjKhn+I5XIsQ5IT6tTObB37kxJ39mFBs0 dTwIvKFrkHZQNjc31FzoKKuhe2AbjSyZtrYNjTIxm8AGva0WpcMXzI6eo4IBSxJ8PL LYznEZmUG7iHbjYM2IHOI6YTUmODP+EG9R5qMwOENgkYY8R2g6NQVze9eZzVpTAnJf FNDzPN5wbagAdByuvMPwqIdX7e6H6Se+s3HmViwWqUpo07MmISg9LUzj11F6Pk/8DB xsEpgNwH7mOtoAb49PflJH8YqdNBelQHUgB+3x+LTnyvmvvGHMx40q0izFRS//ga8I e/aw9jdj5JPWA== From: Sasha Levin To: stable@vger.kernel.org Cc: Longlong Xia , Andrew Morton , Muchun Song , David Hildenbrand , Miaohe Lin , Michal Hocko , Oscar Salvador , Sasha Levin Subject: [PATCH 6.6.y 3/3] mm/hugetlb: do not dissolve gigantic pages without runtime support Date: Tue, 29 Sep 2026 20:03:58 -0400 Message-ID: <20260930000358.2861523-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260930000358.2861523-1-sashal@kernel.org> References: <2026092904-singer-headphone-fefa@gregkh> <20260930000358.2861523-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Longlong Xia [ Upstream commit a363c62a653cc8b3e21da9545fa4e028ef50f9c3 ] dissolve_free_hugetlb_folio() doesn't check hstate_is_gigantic_no_runtime(h) though remove_hugetlb_folio()/ update_and_free_hugetlb_folio() silently bail for such folios, so it frees a still-listed folio and, on vmemmap restore failure, the add_hugetlb_folio() rollback corrupts the free list. Link: https://lore.kernel.org/20260823044118.1097121-2-xialonglong2025@163.com Fixes: 6eb4e88a6d27 ("hugetlb: create remove_hugetlb_page() to separate functionality") Signed-off-by: Longlong Xia Signed-off-by: Andrew Morton Assisted-by: Codex:gpt-5.6-sol Acked-by: Muchun Song Cc: David Hildenbrand Cc: Miaohe Lin Cc: Michal Hocko Cc: Oscar Salvador Cc: Signed-off-by: Sasha Levin --- mm/hugetlb.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index f5b434f2ac474..02bc36d52e2e5 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2314,6 +2314,15 @@ int dissolve_free_huge_page(struct page *page) struct hstate *h = folio_hstate(folio); bool adjust_surplus = false; + /* + * remove_hugetlb_folio()/update_and_free_hugetlb_folio() bail + * for gigantic hstates without runtime support, so dissolving one + * here would leave it on the free list and, on vmemmap restore + * failure, the add_hugetlb_folio() rollback corrupts that list. + */ + if (hstate_is_gigantic_no_runtime(h)) + goto out; + if (!available_huge_pages(h)) goto out; -- 2.53.0