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 C8D9737B417; Mon, 29 Jun 2026 17:41:44 +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=1782754908; cv=none; b=Cu4vhfta/ymUhAz79UgyuXoubJrWBGtCSByd2iARmyH07wjfrfvMQxh+65SA8AlKrHevluH1WZcJUolKejTxYRcgOn70wviYL/l5curxnJD/tD0J96+4iJUCVmfuoMR81h6lciO924GVfcofTTCmtVuFZE2hFMVu0DFZGpVyw38= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782754908; c=relaxed/simple; bh=umCHY0WzhRo9BnV9a4Rue5Pb9esGaLf2ekRSTfsrgUg=; h=Date:To:From:Subject:Message-Id; b=QMEliudPhOTBl+IwcjQDmko4zQ/rYvzy+YefZUrIHMz8+2wDy7pJXbkt94n7UFr6tGlaTAiZ3xISPEesEDT5TLIPaP9uPN2bPNl7hP1Cde/kS2ASvryJBpI0lt6Lok1AFjCi87Xf+zAFJzCnmHjQVbWPpZhM5rP4ZeFQfmwwCAo= 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=RDRWYMEA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="RDRWYMEA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 425081F00A3A; Mon, 29 Jun 2026 17:41:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1782754904; bh=mon0FP5pD7CxKi+sn0r1+EpOnERjsocTWpwnXmAnPI8=; h=Date:To:From:Subject; b=RDRWYMEAV7bqH1etaXbD6Tc5oPw5YnEa2+0lhYBqjftznK1hhZ54kN0DrSiLOyxo8 HELTaBFsStKZeL8Lf2aY23+/FwRD/eCqW2BQjFNkCmYrkVdCUDqse3ljSeoYaFRem+ fMJVCSx+dIENi0a+s7wTUFK3i34l0App+BSbNgbo= Date: Mon, 29 Jun 2026 10:41:43 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,yuzenghui@huawei.com,akpm@linux-foundation.org From: Andrew Morton Subject: + samples-damon-mtier-fail-early-if-address-range-parameters-are-invalid.patch added to mm-hotfixes-unstable branch Message-Id: <20260629174144.425081F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: samples/damon/mtier: fail early if address range parameters are invalid has been added to the -mm mm-hotfixes-unstable branch. Its filename is samples-damon-mtier-fail-early-if-address-range-parameters-are-invalid.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/samples-damon-mtier-fail-early-if-address-range-parameters-are-invalid.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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: Zenghui Yu Subject: samples/damon/mtier: fail early if address range parameters are invalid Date: Mon, 29 Jun 2026 07:44:31 -0700 The comment on top of `struct damon_region` clearly says that For any use case, @ar should be non-zero positive size. which is now verified in damon_verify_new_region() if the kernel is built with DAMON_DEBUG_SANITY. The WARN_ONCE() can be triggered if the mtier sample module is enabled before node{0,1}_{start,end}_addr have been properly initialized, which is obviously not good. ------------[ cut here ]------------ start 0 >= end 0 WARNING: mm/damon/core.c:217 at damon_new_region+0xf4/0x118, CPU#59: bash/341468 Call trace: damon_new_region+0xf4/0x118 (P) damon_set_regions+0xfc/0x3c0 damon_sample_mtier_build_ctx+0xe8/0x3a8 damon_sample_mtier_start+0x1c/0x90 damon_sample_mtier_enable_store+0x98/0xb0 param_attr_store+0xb4/0x128 module_attr_store+0x2c/0x50 sysfs_kf_write+0x58/0x90 kernfs_fop_write_iter+0x16c/0x238 vfs_write+0x2c0/0x370 ksys_write+0x74/0x118 __arm64_sys_write+0x24/0x38 invoke_syscall+0xa8/0x118 el0_svc_common.constprop.0+0x48/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x54/0x370 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Note that the same issue can happen if detect_node_addresses is true, and node 0 or 1 is memoryless. Fix it together by checking the validity of parameters right before damon_new_region() and fail early if they're invalid. Link: https://lore.kernel.org/20260629144432.133962-1-sj@kernel.org Fixes: 82a08bde3cf7 ("samples/damon: implement a DAMON module for memory tiering") Signed-off-by: Zenghui Yu Signed-off-by: SJ Park Reviewed-by: SJ Park Cc: # 6.16.x Signed-off-by: Andrew Morton --- samples/damon/mtier.c | 3 +++ 1 file changed, 3 insertions(+) --- a/samples/damon/mtier.c~samples-damon-mtier-fail-early-if-address-range-parameters-are-invalid +++ a/samples/damon/mtier.c @@ -120,6 +120,9 @@ static struct damon_ctx *damon_sample_mt addr.end = promote ? node1_end_addr : node0_end_addr; } + if (addr.start >= addr.end) + goto free_out; + range.start = addr.start; range.end = addr.end; _ Patches currently in -mm which might be from yuzenghui@huawei.com are samples-damon-mtier-fail-early-if-address-range-parameters-are-invalid.patch