From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DFDFE183CA6; Mon, 12 Aug 2024 16:22:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723479743; cv=none; b=mB9gOW4pRR6vX5dKIZnOnGi7WPn0tYdJiWOOCQRCoR4hr6C5uVrOT553sHtcsf2TO7FJRchcxlScHNmix1Y8dJTPPDIBb5VWini72Ws+z4pU+fcJVizuQ+dA33gWUlX0YuMGq7J2T+S92ASlVGtPOYfcL2EKHkavMZwrNWewydM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723479743; c=relaxed/simple; bh=5EbgAV3bjjBWfqPYxblcSthcVdvg6AXDg/KRVF+W8SU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mzyNfOdKTtZMIrq1hztj+YVB9sTSl3YZ6RvxpCor+dKUudfH8xGDwjHvnIlLeA7Kl8sv/A5kC181O/rT4/NoJAKWnJjFfMPW8sMrLqSAGjrvxqVyNe0CcCo2rVSDaaILfWqLUnqiGt5yLaKW3z1tHygGs3lbcVDiWRkwWGFhUZo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DGt1aAl5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="DGt1aAl5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 679EFC32782; Mon, 12 Aug 2024 16:22:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723479742; bh=5EbgAV3bjjBWfqPYxblcSthcVdvg6AXDg/KRVF+W8SU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DGt1aAl5Rkl/jeylVMUl1S2XTBFVAQnJQ903S8qgR/lh92OBSCtqNP5rLppkrepxx 6ftLxQYRxomHhI84c5PEjhw1Ngm0quQFVEMcQIQRqPShHxphTsCuemuh1VVz5ratov 7XO3nHzC+cZr12p0+SiN7yQwKNGSNCQl4GgTS9dI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Miaohe Lin , Muchun Song , Oscar Salvador , Andrew Morton Subject: [PATCH 6.6 179/189] mm/hugetlb: fix potential race in __update_and_free_hugetlb_folio() Date: Mon, 12 Aug 2024 18:03:55 +0200 Message-ID: <20240812160139.036711671@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240812160132.135168257@linuxfoundation.org> References: <20240812160132.135168257@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Miaohe Lin commit 5596d9e8b553dacb0ac34bcf873cbbfb16c3ba3e upstream. There is a potential race between __update_and_free_hugetlb_folio() and try_memory_failure_hugetlb(): CPU1 CPU2 __update_and_free_hugetlb_folio try_memory_failure_hugetlb folio_test_hugetlb -- It's still hugetlb folio. folio_clear_hugetlb_hwpoison spin_lock_irq(&hugetlb_lock); __get_huge_page_for_hwpoison folio_set_hugetlb_hwpoison spin_unlock_irq(&hugetlb_lock); spin_lock_irq(&hugetlb_lock); __folio_clear_hugetlb(folio); -- Hugetlb flag is cleared but too late. spin_unlock_irq(&hugetlb_lock); When the above race occurs, raw error page info will be leaked. Even worse, raw error pages won't have hwpoisoned flag set and hit pcplists/buddy. Fix this issue by deferring folio_clear_hugetlb_hwpoison() until __folio_clear_hugetlb() is done. So all raw error pages will have hwpoisoned flag set. Link: https://lkml.kernel.org/r/20240708025127.107713-1-linmiaohe@huawei.com Fixes: 32c877191e02 ("hugetlb: do not clear hugetlb dtor until allocating vmemmap") Signed-off-by: Miaohe Lin Acked-by: Muchun Song Reviewed-by: Oscar Salvador Cc: Signed-off-by: Andrew Morton Signed-off-by: Miaohe Lin Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1770,13 +1770,6 @@ static void __update_and_free_hugetlb_fo } /* - * Move PageHWPoison flag from head page to the raw error pages, - * which makes any healthy subpages reusable. - */ - if (unlikely(folio_test_hwpoison(folio))) - folio_clear_hugetlb_hwpoison(folio); - - /* * If vmemmap pages were allocated above, then we need to clear the * hugetlb destructor under the hugetlb lock. */ @@ -1787,6 +1780,13 @@ static void __update_and_free_hugetlb_fo } /* + * Move PageHWPoison flag from head page to the raw error pages, + * which makes any healthy subpages reusable. + */ + if (unlikely(folio_test_hwpoison(folio))) + folio_clear_hugetlb_hwpoison(folio); + + /* * Non-gigantic pages demoted from CMA allocated gigantic pages * need to be given back to CMA in free_gigantic_folio. */