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 9E043382; Sun, 20 Jul 2025 18:58:27 +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=1753037907; cv=none; b=IrenaqEHHZ8FO56GrtOOqaOMzOEJuDVvl8VQcqbfywP1aI9dIsxKribFwtNE7y4+a14qR2Vj0D4vioePRy0ljZORdYfFJJHcHAwY28Rej5Lslw83PdWSg5rf2w87ytiVBkC1Y1c1HgVGHblGW6TFwp4FpgL9vxv+HhfdWNi7XeU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753037907; c=relaxed/simple; bh=Z4K/L8iVI8412mIfKRLloP1W+n/XlOZFFt9DKKoURFg=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=BNmpT9CxMEf69sXiW8KwNeonTVLoiIRvV4Ew7xqyL1rqdklI0tFWWKR/Ei5Ag7a6MKCi2szbIFbSMUPQjeK76njTuzau9UFZnwWy9gsg/8nT76oIPfvhyf1p6m31PdYzZ70FtkWukVi/2cGT9+e5lD5G5pYPChD14rOcAxN1+hE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UWJyWLpy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UWJyWLpy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0169AC4CEE7; Sun, 20 Jul 2025 18:58:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753037907; bh=Z4K/L8iVI8412mIfKRLloP1W+n/XlOZFFt9DKKoURFg=; h=From:To:Cc:Subject:Date:From; b=UWJyWLpyXtMe4KYH3Ztyry35J19Ro8R2rER8oyZh6JGgNMnlVXYl+OE2S7ggDWLg2 z6ZmJjf2j4FW2J2mv83Lgll2m8yB4EcoxaQLyDclqT8HZtboSXYoLbTCd6tz6w/Ioa 1qTLh0Fw9iRuYgVUlvCIEhW/U9IZy0cfWHgWCLCaXNLZa1gqS1nHd4qp0F2G9/2QJJ wm7xmqpzIkKQsxfCczGpGdcYYiMdfuRD+nt+3ND8bAbzwNjE61tj6PUkZ0U6Z1YWND 4C7UYd5U5CE5qk1Jl0N/UkOA/bQnxhs+Tf7zr+R1Kst8YTKxP9QmACHFRER4PqR5cX zy9aRfDiA+7+Q== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , Honggyu Kim , Hyeongtak Ji , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org Subject: [PATCH] mm/damon/ops-common: ignore migration request to invalid nodes Date: Sun, 20 Jul 2025 11:58:22 -0700 Message-Id: <20250720185822.1451-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit damon_migrate_pages() try migration even if the target node is invalid. If users mistakenly make such invalid requests via DAMOS_MIGRATE_{HOT,COLD} action, below kernel BUG can happen. [ 7831.883495] BUG: unable to handle page fault for address: 0000000000001f48 [ 7831.884160] #PF: supervisor read access in kernel mode [ 7831.884681] #PF: error_code(0x0000) - not-present page [ 7831.885203] PGD 0 P4D 0 [ 7831.885468] Oops: Oops: 0000 [#1] SMP PTI [ 7831.885852] CPU: 31 UID: 0 PID: 94202 Comm: kdamond.0 Not tainted 6.16.0-rc5-mm-new-damon+ #93 PREEMPT(voluntary) [ 7831.886913] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.el9 04/01/2014 [ 7831.887777] RIP: 0010:__alloc_frozen_pages_noprof (include/linux/mmzone.h:1724 include/linux/mmzone.h:1750 mm/page_alloc.c:4936 mm/page_alloc.c:5137) [...] [ 7831.895953] Call Trace: [ 7831.896195] [ 7831.896397] __folio_alloc_noprof (mm/page_alloc.c:5183 mm/page_alloc.c:5192) [ 7831.896787] migrate_pages_batch (mm/migrate.c:1189 mm/migrate.c:1851) [ 7831.897228] ? __pfx_alloc_migration_target (mm/migrate.c:2137) [ 7831.897735] migrate_pages (mm/migrate.c:2078) [ 7831.898141] ? __pfx_alloc_migration_target (mm/migrate.c:2137) [ 7831.898664] damon_migrate_folio_list (mm/damon/ops-common.c:321 mm/damon/ops-common.c:354) [ 7831.899140] damon_migrate_pages (mm/damon/ops-common.c:405) [...] Add a target node validity check in damon_migrate_pages(). The validity check is stolen from that of do_pages_move(), which is being used for move_pages() system call. Fixes: b51820ebea65 ("mm/damon/paddr: introduce DAMOS_MIGRATE_COLD action for demotion") # 6.11.x Cc: stable@vger.kernel.org Cc: Honggyu Kim Signed-off-by: SeongJae Park --- mm/damon/ops-common.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c index 6a9797d1d7ff..99321ff5cb92 100644 --- a/mm/damon/ops-common.c +++ b/mm/damon/ops-common.c @@ -383,6 +383,10 @@ unsigned long damon_migrate_pages(struct list_head *folio_list, int target_nid) if (list_empty(folio_list)) return nr_migrated; + if (target_nid < 0 || target_nid >= MAX_NUMNODES || + !node_state(target_nid, N_MEMORY)) + return nr_migrated; + noreclaim_flag = memalloc_noreclaim_save(); nid = folio_nid(lru_to_folio(folio_list)); base-commit: e2c90d41402c324ea81fa3d9c2c1d0f61906c161 -- 2.39.5