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 AC2E529E116; Mon, 4 May 2026 14:21:54 +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=1777904514; cv=none; b=eTuG1dhZl8vXkwEwqYv3jEGFOBm4aqvfU+CuxN3rzi9PajVmh7mldFfOvQD6QH4l3zifMozchAbkha/Y2bELgut5YYSzDo4CXRrox3lVCN97W9K/GLQDHaSMjLXvf3gon3vArNNYTyHRDn+Lqvgw9kKjZXOjmCVOe0bkOlZFvjQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777904514; c=relaxed/simple; bh=3lSvyk/ezsF2m/sYUOVHlGEhr7WwGs8cU3ZPB5rN8R8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=p6WBf1hWdZGm3rEzZj6RjMECbuK/e+sIEe0U1iJUoiQf4/hUnZaqamn/3oriTVXYOpAlKOJRKNk++T8Nqk8JnO49Xk07Kna/X6993lgYwEKP/0Lgz25I7vXJD+ayPign+/p5Z5g3YXWmYvSysdEJMOsk302aGm7o9w5+2gUCZYk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1PnR5zK2; 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="1PnR5zK2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A853C2BCB8; Mon, 4 May 2026 14:21:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777904514; bh=3lSvyk/ezsF2m/sYUOVHlGEhr7WwGs8cU3ZPB5rN8R8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1PnR5zK2CPl+jSPTZ1S431ic+LiZiaT5BwXT6KDhZILf8INWg30l3O3wuFWm1N+sf B58g01/n4bfCqpdU9d4d03Zzqq1JDO0M7n5nfiU1kgvBe0+sQL2kMefxEwUAgZupRi 54h9jnLlWZYstn1vlT3sIpPG5ysy7bEKOMSVtioA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jinjiang Tu , David Hildenbrand , Zi Yan , Miaohe Lin , Kefeng Wang , Luis Chamberalin , "Matthew Wilcox (Oracle)" , Michal Hocko , Oscar Salvador , Pankaj Raghav , Andrew Morton , Alexandra Diupina , Sasha Levin Subject: [PATCH 6.12 035/215] mm/memory_hotplug: fix hwpoisoned large folio handling in do_migrate_range() Date: Mon, 4 May 2026 15:50:54 +0200 Message-ID: <20260504135131.460056540@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260504135130.169210693@linuxfoundation.org> References: <20260504135130.169210693@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jinjiang Tu commit 397f6d14f9c370e4910e6885294c340f39dedbf5 upstream. In do_migrate_range(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). I can reproduce this issue in qemu after adding delay in memory_failure() BUG: kernel NULL pointer dereference, address: 0000000000000000 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:try_to_unmap_one+0x16a/0xfc0 rmap_walk_anon+0xda/0x1f0 try_to_unmap+0x78/0x80 ? __pfx_try_to_unmap_one+0x10/0x10 ? __pfx_folio_not_mapped+0x10/0x10 ? __pfx_folio_lock_anon_vma_read+0x10/0x10 unmap_poisoned_folio+0x60/0x140 do_migrate_range+0x4d1/0x600 ? slab_memory_callback+0x6a/0x190 ? notifier_call_chain+0x56/0xb0 offline_pages+0x3e6/0x460 memory_subsys_offline+0x130/0x1f0 device_offline+0xba/0x110 acpi_bus_offline+0xb7/0x130 acpi_scan_hot_remove+0x77/0x290 acpi_device_hotplug+0x1e0/0x240 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x186/0x340 Besides, do_migrate_range() may be called between memory_failure set hwpoison flag and isolate the folio from lru, so remove WARN_ON(). In other places, unmap_poisoned_folio() is called when the folio is isolated, obey it in do_migrate_range() too. [david@redhat.com: don't abort offlining, fixed typo, add comment] Link: https://lkml.kernel.org/r/3c214dff-9649-4015-840f-10de0e03ebe4@redhat.com Fixes: b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined") Signed-off-by: Jinjiang Tu Signed-off-by: David Hildenbrand Acked-by: Zi Yan Reviewed-by: Miaohe Lin Cc: Kefeng Wang Cc: Luis Chamberalin Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Oscar Salvador Cc: Pankaj Raghav Signed-off-by: Andrew Morton Signed-off-by: Alexandra Diupina Signed-off-by: Sasha Levin --- mm/memory_hotplug.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0a42e9a8caba2..16d788547b9b6 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1802,8 +1802,14 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) goto put_folio; if (folio_contain_hwpoisoned_page(folio)) { - if (WARN_ON(folio_test_lru(folio))) - folio_isolate_lru(folio); + /* + * unmap_poisoned_folio() cannot handle large folios + * in all cases yet. + */ + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) + goto put_folio; + if (folio_test_lru(folio) && !folio_isolate_lru(folio)) + goto put_folio; if (folio_mapped(folio)) { folio_lock(folio); unmap_poisoned_folio(folio, pfn, false); -- 2.53.0