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 8903E31195C for ; Wed, 29 Jul 2026 14:00:28 +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=1785333631; cv=none; b=q6hBR2N2KURcy+HtpXxjQJ9EsTcvnTIerLlIjaroIMDVYjLHNsFVqzQ5LQKV9GaT+5a1KuJV2orrcrCqdm3D4Aq9Cr66NaMJa/xEwc0t1AachsqV7KJUkHEdR9Yxlnjkvd5oxuwaF5lF+SOOQFq/jJ7afw5egrbIyoY+Qc+cRj0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785333631; c=relaxed/simple; bh=F7URkF2o9i+e+5L+hvdhy8dA0w9EG3iFsh6FKrm6rgU=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=XaVv4RMWfKiHWB8zANKY/UdgSTwaEaUbk9PxxqgPMEN8FAudNQx4TcRL8/V2JSreWQBSpDZJQlKe+Eml748EbhePDBwaN+vQU6w00Ou00uDQavLyvSvLUFAKPDgnqgs11W7ah5SMCrvlQ3Lbwi8/liNXUNfO8gpA5QA4dmAmSRs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pcq9Sz9r; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="pcq9Sz9r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E111A1F00A3E; Wed, 29 Jul 2026 14:00:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785333625; bh=cqaMLQoP4cQ64ijRrbBqNTstWmlqWieVCWdB6Qm9LyU=; h=Subject:To:Cc:From:Date; b=pcq9Sz9r6au7obIvrsyb1lUdwbHqAKKOjbvbyhSwQ0Ko+6TtOmsi0Jqlav7GAJ8bw Ffddp+PqLuMKD2GeiTdgu5KOEzP/cZtemQyT1EgaO22q2r9TZVYll0EkGA5ReoXu/V erDbXjw8OX0K1Rto4IoEFltIVYV29E4scTWolN+E= Subject: FAILED: patch "[PATCH] mm/damon/core: validate ranges in damon_set_regions()" failed to apply to 6.6-stable tree To: sj@kernel.org,akpm@linux-foundation.org,stable@vger.kernel.org,yangyingliang@huawei.com Cc: From: Date: Wed, 29 Jul 2026 15:58:01 +0200 Message-ID: <2026072901-unmarked-salvage-c2a5@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 1292c0ecb1caefb8ca064a3639d5673991e8810c # git commit -s git send-email --to '' --in-reply-to '2026072901-unmarked-salvage-c2a5@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1292c0ecb1caefb8ca064a3639d5673991e8810c Mon Sep 17 00:00:00 2001 From: SJ Park Date: Mon, 29 Jun 2026 20:52:19 -0700 Subject: [PATCH] mm/damon/core: validate ranges in damon_set_regions() DAMON core logic assumes zero length regions don't exist. However, a few DAMON API callers including DAMON_SYSFS, DAMON_RECLAIM and DAMON_LRU_SORT allow users to set empty monitoring target regions. This could result in WARN_ONCE() on CONFIG_DAMON_DEBUG_SANITY enabled kernel, and divide-by-zero from damon_merge_two_regions(). For example, the WANR_ONCE() can be triggered like below. # grep DAMON_DEBUG_SANITY /boot/config-$(uname -r) # CONFIG_DAMON_DEBUG_SANITY=y # damo start # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/0/targets/0/regions/0/start # echo 0 > contexts/0/targets/0/regions/0/end # echo commit > state # dmesg [....] [ 73.705780] ------------[ cut here ]------------ [ 73.707552] start 0 >= end 0 [ 73.708452] WARNING: mm/damon/core.c:359 at damon_new_region+0x6e/0x80, CPU#1: kdamond.0/758 [...] All DAMON API callers eventually use damon_set_regions() to setup the regions. Add the validation logic in the function. Link: https://lore.kernel.org/20260630035221.146458-1-sj@kernel.org Fixes: 43b0536cb471 ("mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)") Signed-off-by: SJ Park Cc: Yang yingliang Cc: # 5.16.x Signed-off-by: Andrew Morton diff --git a/mm/damon/core.c b/mm/damon/core.c index d99f7a297fdd..949d5309d54d 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -356,6 +356,12 @@ int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, unsigned int i; int err; + for (i = 0; i < nr_ranges; i++) { + if (ALIGN_DOWN(ranges[i].start, min_region_sz) >= + ALIGN(ranges[i].end, min_region_sz)) + return -EINVAL; + } + /* Remove regions which are not in the new ranges */ damon_for_each_region_safe(r, next, t) { for (i = 0; i < nr_ranges; i++) {