From nobody Fri Jan 2 04:02:10 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E163C41513 for ; Sun, 15 Oct 2023 20:27:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230405AbjJOU1B (ORCPT ); Sun, 15 Oct 2023 16:27:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229990AbjJOU07 (ORCPT ); Sun, 15 Oct 2023 16:26:59 -0400 Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 955CCC1 for ; Sun, 15 Oct 2023 13:26:57 -0700 (PDT) Received: by mail-wr1-x42f.google.com with SMTP id ffacd0b85a97d-32db8f8441eso24292f8f.0 for ; Sun, 15 Oct 2023 13:26:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697401616; x=1698006416; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=9mJQUt7Wf0+dPq/8JTeI94cIlxhXMv5ZBTCjETmdTqU=; b=fP8Sj+Zmgowryvn3edaUpvRhj5ctaNKQFZeTysSjAZKduvzY/o+aQ6Jj0kMakxC0kT RMVBkwehKFD4d0cEdjDRQAYqJtlnU5aWr/vk9kKeFJRkxWSy4N+r0y5ytkuRzNaSycFr /mBzW5GQtaGoEkrRFVgr/yV1fAwQFYPWWrTyc7aVln2QIz+/I2vBCyvmHeUvqWWm+oud pGeh4ROzyk0Np/O5cjxAkt6ZA3vAHbkHefCvL0XVO8gN+9ym9Jl58nmyFMGPWD5X3O/u XRE18d0uTbEfvk5fMm77esD/uH00Ui1qigGEGvUwqNCfqJy//Gy1V5CHqy6hlnowNL3D Mr1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697401616; x=1698006416; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=9mJQUt7Wf0+dPq/8JTeI94cIlxhXMv5ZBTCjETmdTqU=; b=jCWCaR1QEN4VxxYebUF9l0K5d3ow4tDIcYV/+vCi3hG4QELmUL2y3SD31pEnHoSXA9 pnlVAsl6Xli7+etOTyvZtS2aUwEl3DggHOs2eUiFLCv+Cjh3l4exb4nYDlF7IriR70Gq 6kPbEWf6A/rj2rKVT48YkDc663R5rClXEGvSoq+p/Ixq087dlF78yXbZp6zvXI3pDKQY NqvePKkn1/7lzyOB1Fgqo0rRhlBEnKYJt0MlUEVXCysvFJn4XykeS4gTL241rnV5UuAH hMt7b2Si7IVrQHWEAVlAOinzXDseMyAiKn7M8uobwOLCZdEXM7jreeUI+aWg8B7kZXH8 zQ6A== X-Gm-Message-State: AOJu0YyxZznIPSOeO2TCMLee6m8JkSkzkQObWBUTHy7p5UvlOI7Pneak oxGaQADkIEgcRGYYG+6seDE= X-Google-Smtp-Source: AGHT+IE39XZwC0ne09DLeEYAEDmDf3xkSkL6BIj3dVUMU1+rWVkbO5e5YJUqWsPJnfwvd93Lb7r9Yg== X-Received: by 2002:a05:6000:1189:b0:321:6936:c217 with SMTP id g9-20020a056000118900b003216936c217mr26180665wrx.14.1697401615768; Sun, 15 Oct 2023 13:26:55 -0700 (PDT) Received: from PC-PEDRO-ARCH.lan ([2001:8a0:7280:5801:9441:3dce:686c:bfc7]) by smtp.gmail.com with ESMTPSA id u1-20020adfa181000000b0032da49e18fasm4303429wru.23.2023.10.15.13.26.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Oct 2023 13:26:55 -0700 (PDT) From: Pedro Falcato To: kasan-dev@googlegroups.com, Alexander Potapenko Cc: Marco Elver , Dmitry Vyukov , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Pedro Falcato Subject: [PATCH] mm: kmsan: Panic on failure to allocate early boot metadata Date: Sun, 15 Oct 2023 21:26:50 +0100 Message-ID: <20231015202650.85777-1-pedro.falcato@gmail.com> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Given large enough allocations and a machine with low enough memory (i.e a default QEMU VM), it's entirely possible that kmsan_init_alloc_meta_for_range's shadow+origin allocation fails. Instead of eating a NULL deref kernel oops, check explicitly for memblock_a= lloc() failure and panic with a nice error message. Signed-off-by: Pedro Falcato --- mm/kmsan/shadow.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/kmsan/shadow.c b/mm/kmsan/shadow.c index 87318f9170f..3dae3d9c0b3 100644 --- a/mm/kmsan/shadow.c +++ b/mm/kmsan/shadow.c @@ -285,12 +285,18 @@ void __init kmsan_init_alloc_meta_for_range(void *sta= rt, void *end) size =3D PAGE_ALIGN((u64)end - (u64)start); shadow =3D memblock_alloc(size, PAGE_SIZE); origin =3D memblock_alloc(size, PAGE_SIZE); + + if (!shadow || !origin) + panic("%s: Failed to allocate metadata memory for early boot range " + "of size %llu", + __func__, size); + for (u64 addr =3D 0; addr < size; addr +=3D PAGE_SIZE) { page =3D virt_to_page_or_null((char *)start + addr); - shadow_p =3D virt_to_page_or_null((char *)shadow + addr); + shadow_p =3D virt_to_page((char *)shadow + addr); set_no_shadow_origin_page(shadow_p); shadow_page_for(page) =3D shadow_p; - origin_p =3D virt_to_page_or_null((char *)origin + addr); + origin_p =3D virt_to_page((char *)origin + addr); set_no_shadow_origin_page(origin_p); origin_page_for(page) =3D origin_p; } --=20 2.42.0