From nobody Mon Feb 9 12:42:54 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 588CF28C869 for ; Sun, 21 Dec 2025 12:26:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766320020; cv=none; b=bWCAh1dW30pXcAmUonady2DwnqfZwdjDK7XS11JShqsAPy15BVMC+246hs4YP8+LyAYgo0c/CjV79RzVZHDFIXaFUZHxl3wT+H+Xu3r/X3Yjfr3ov5ZqdoSjuSNEQGhUKRBuCsYYdcMsIARFIW9KYzYmoHnLfIisGQJ+lO7nIR0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766320020; c=relaxed/simple; bh=B4sZdJG1t9EctDBIEt1ugcR+phuCjNoMUoxASwFgC4c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Hqf4H4FpJ38/QADdaqOWUM9k948lYZXil82fhXELGGJBfcs296qXRpW4HnKO5L1Ywmk9/n5tj05xs6vAB0LM422B2oUkDRqB4Q3+3V6jChRNZryuxnTdIpalHMq6AVvnWlR3cgo1BhImEgSWgd0Wfsb3sj6J7i6ouZ7NLN02KS8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=GcoFNiwz; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GcoFNiwz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1766320018; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Q/oaz55RIgwHHbP5HbFfkXnPCuvWreBFUWRc63qZ0WQ=; b=GcoFNiwztl+niIwsesJl/3gs49J4yAGhp5ipfMXlGQciAro42wn9suEI/sTdpOAVPhFzuC l6Y0HdK2W2YZFteYbHrVdHUfInJLDc+ZklV3NFSAw92IjbQRnGbyi9N42xhq9ym9T6zuFU CbqGJJhwKx7YBqdrqeJ6OFGJYfmuiNk= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-683-K90Ry8O3Os-k_MrDsuatRA-1; Sun, 21 Dec 2025 07:26:53 -0500 X-MC-Unique: K90Ry8O3Os-k_MrDsuatRA-1 X-Mimecast-MFC-AGG-ID: K90Ry8O3Os-k_MrDsuatRA_1766320011 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7DC6D1800358; Sun, 21 Dec 2025 12:26:51 +0000 (UTC) Received: from dell-per7425-02.rhts.eng.pek2.redhat.com (dell-per7425-02.rhts.eng.pek2.redhat.com [10.73.116.18]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9EFE119560B4; Sun, 21 Dec 2025 12:26:47 +0000 (UTC) From: Li Wang To: akpm@linux-foundation.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: David Hildenbrand , Mark Brown , Shuah Khan , Waiman Long Subject: [PATCH v3 1/3] selftests/mm/write_to_hugetlbfs: parse -s as size_t Date: Sun, 21 Dec 2025 20:26:37 +0800 Message-ID: <20251221122639.3168038-2-liwang@redhat.com> In-Reply-To: <20251221122639.3168038-1-liwang@redhat.com> References: <20251221122639.3168038-1-liwang@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Content-Type: text/plain; charset="utf-8" write_to_hugetlbfs currently parses the -s size argument with atoi() into an int. This silently accepts malformed input, cannot report overflow, and can truncate large sizes. Acked-by: David Hildenbrand (Red Hat) Acked-by: Waiman Long --- Error log --- # uname -r 6.12.0-xxx.el10.aarch64+64k # ls /sys/kernel/mm/hugepages/hugepages-* hugepages-16777216kB/ hugepages-2048kB/ hugepages-524288kB/ #./charge_reserved_hugetlb.sh -cgroup-v2 # ----------------------------------------- ... # nr hugepages =3D 10 # writing cgroup limit: 5368709120 # writing reseravation limit: 5368709120 ... # Writing to this path: /mnt/huge/test # Writing this size: -1610612736 <-------- Switch the size variable to size_t and parse -s with sscanf("%zu", ...). Also print the size using %zu. This avoids incorrect behavior with large -s values and makes the utility more robust. Signed-off-by: Li Wang Cc: David Hildenbrand Cc: Mark Brown Cc: Shuah Khan Cc: Waiman Long Acked-by: David Hildenbrand (Red Hat) --- tools/testing/selftests/mm/write_to_hugetlbfs.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/mm/write_to_hugetlbfs.c b/tools/testin= g/selftests/mm/write_to_hugetlbfs.c index 34c91f7e6128..ecb5f7619960 100644 --- a/tools/testing/selftests/mm/write_to_hugetlbfs.c +++ b/tools/testing/selftests/mm/write_to_hugetlbfs.c @@ -68,7 +68,7 @@ int main(int argc, char **argv) int key =3D 0; int *ptr =3D NULL; int c =3D 0; - int size =3D 0; + size_t size =3D 0; char path[256] =3D ""; enum method method =3D MAX_METHOD; int want_sleep =3D 0, private =3D 0; @@ -86,7 +86,10 @@ int main(int argc, char **argv) while ((c =3D getopt(argc, argv, "s:p:m:owlrn")) !=3D -1) { switch (c) { case 's': - size =3D atoi(optarg); + if (sscanf(optarg, "%zu", &size) !=3D 1) { + perror("Invalid -s."); + exit_usage(); + } break; case 'p': strncpy(path, optarg, sizeof(path) - 1); @@ -131,7 +134,7 @@ int main(int argc, char **argv) } =20 if (size !=3D 0) { - printf("Writing this size: %d\n", size); + printf("Writing this size: %zu\n", size); } else { errno =3D EINVAL; perror("size not found"); --=20 2.49.0