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 7214C386C31 for ; Tue, 12 May 2026 21:40:38 +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=1778622038; cv=none; b=FiiDuLmskBrRcbJrpGARQm79Rl+VsCHAHKQQ9Pbzc6UUKzUV/xjaqnRlAHtjNwBx7FMS2/lZ50tS1BqRqGWmNSRF1pPsXJZ+YxmGtnLLvH/4oIKq+WvfgutVMjYpKEhQLdzJVxfjJJu7QJRkmRXw1/Iz2kQuTGjXjJywy1nSaGY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778622038; c=relaxed/simple; bh=zW6yY7gJ3mXXnLlIOEgI6+vX6GDkneqQWXDGgy0+Afk=; h=Date:To:From:Subject:Message-Id; b=LqP9I1YVcf1VtI7OMhktT7HVCT5dM9JyDdhFd0pwaNOTgZUg/fCZbus/I4Ofe4kgsBjOxWxngMYU07twqrBRYIKyMJX9/oqdamqkiVz3P3DD+ih6KFVQdL3bx4D96iZBX333ywfKN6QMXiOJAQ5RMh5aOg7se63FuUgKJiZ9nA0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=FvN3Q3vC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="FvN3Q3vC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 172FEC2BCB0; Tue, 12 May 2026 21:40:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1778622038; bh=zW6yY7gJ3mXXnLlIOEgI6+vX6GDkneqQWXDGgy0+Afk=; h=Date:To:From:Subject:From; b=FvN3Q3vCtgb7EL9g/pFdwsyDFQlP8bfvGXW0yD6BSeG5aoIOHRd35J4tMiUAp7P/T hWwVMImdTb8NgnZxW0130hqsoaiX0Ap1owbyKloykmh3UZACgfofdG/C7mG1EBObA7 mpNSlOGtdfr+eiV3fmmo8JPHOnuSsWG2CBJIheUs= Date: Tue, 12 May 2026 14:40:37 -0700 To: mm-commits@vger.kernel.org,sj@kernel.org,aethernet65535@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-damon-reclaim-validate-min_region_size-to-be-power-of-2.patch added to mm-new branch Message-Id: <20260512214038.172FEC2BCB0@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/damon/reclaim: validate min_region_size to be power of 2 has been added to the -mm mm-new branch. Its filename is mm-damon-reclaim-validate-min_region_size-to-be-power-of-2.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-reclaim-validate-min_region_size-to-be-power-of-2.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Liew Rui Yan Subject: mm/damon/reclaim: validate min_region_size to be power of 2 Date: Fri, 1 May 2026 09:37:50 +0800 Problem ======= When a user sets an invalid 'addr_unit' (e.g., 3) via DAMON_RECLAIM, 'min_region_sz' becomes a non-power-of-2 value. While damon_commit_ctx() correctly detects this and returns -EINVAL, it sets the 'maybe_corrupted' flag during this process. This flag causes the running kdamond to terminate. While the termination is a safety measure, it is suboptimal in this case because the error is just a simple invalid input from the user, which shouldn't neccessitate stopping the kdamond. Reproduction ============ 1. Enable DAMON_RECLAIM 2. Set addr_unit=3 3. Commit inputs via 'commit_inputs' 4. Observe kdamond termination Solution ======== Add an early validation in damon_reclaim_apply_parameters() to check 'min_region_sz' before any state change occurs. If it is non-power-of-2, return -EINVAL immediately, preventing 'maybe_corrupted' from being set. Link: https://lore.kernel.org/20260501013750.71704-3-aethernet65535@gmail.com Signed-off-by: Liew Rui Yan Reviewed-by: SeongJae Park Signed-off-by: Andrew Morton --- mm/damon/reclaim.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/mm/damon/reclaim.c~mm-damon-reclaim-validate-min_region_size-to-be-power-of-2 +++ a/mm/damon/reclaim.c @@ -210,6 +210,11 @@ static int damon_reclaim_apply_parameter param_ctx->addr_unit = addr_unit; param_ctx->min_region_sz = max(DAMON_MIN_REGION_SZ / addr_unit, 1); + if (!is_power_of_2(param_ctx->min_region_sz)) { + err = -EINVAL; + goto out; + } + if (!damon_reclaim_mon_attrs.aggr_interval) { err = -EINVAL; goto out; _ Patches currently in -mm which might be from aethernet65535@gmail.com are mm-damon-ops-common-optimize-damon_hot_score-using-ilog2.patch mm-damon-add-synchronous-commit-for-commit_inputs.patch mm-damon-lru_sort-validate-min_region_size-to-be-power-of-2.patch mm-damon-reclaim-validate-min_region_size-to-be-power-of-2.patch