From patchwork Sat May 6 02:47:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peng Zhang X-Patchwork-Id: 13233262 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99363C77B75 for ; Sat, 6 May 2023 02:48:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 26EFE6B0078; Fri, 5 May 2023 22:48:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 21F5E6B0081; Fri, 5 May 2023 22:48:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 135B46B0082; Fri, 5 May 2023 22:48:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pg1-f172.google.com (mail-pg1-f172.google.com [209.85.215.172]) by kanga.kvack.org (Postfix) with ESMTP id E17F46B0078 for ; Fri, 5 May 2023 22:48:00 -0400 (EDT) Received: by mail-pg1-f172.google.com with SMTP id 41be03b00d2f7-5144043d9d1so1674800a12.3 for ; Fri, 05 May 2023 19:48:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1683341280; x=1685933280; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=1IB1K/l9/1FqQriErcMqKq+JgBm37xydqS13nuO5aWY=; b=W9/AMeOlh/lAOx41PZNmzXw9cTtRfF3hF9Z6FPXosI17UzVAGVOhKYFkILWrD7FeqM /mWZLlEMfRFqD8tbJdnVbGZouCsE1yFOAJ7K8eQwFeEScnE9Pof7H0Yb3RWMhCJMDfov 1Q5SNztBaOOvC24TsPrAob53VgnSoPrvq1MvswWcufbXXKHZvJ+JtTFOHg57BFctMY8+ mjIOY7KYmK7NNYEo6dzLv0xyyKtanWRko7H914RlHSn8Ztk3q5n8LskYNd9jFb0Iou8G 9eUfHXu8J+uq14NANWSm3ZFyHXhcZO5l9cevDhhjoGXwaWDwgW7/Vn1be0VqtDY6Nauo x+ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683341280; x=1685933280; 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=1IB1K/l9/1FqQriErcMqKq+JgBm37xydqS13nuO5aWY=; b=M2wBnaUNjW3pBb8h+9s4Rg5+0TztZE1+qiW0cc09o1NwGuYD1k9AdJfXLZzPmVPo03 7FOHrkuCQ3tKVZSHok6GlBqG6ehCVW18YSF1yL+XatTvcNa8NxgPInD266jvIXR3ImHC P/zkr/YXKxa2nj5IzLYW8t0YxQ4u6gLzUJ0YUN+4fZUUcHHVI3Hc+kQQIZvoAm9OrApU vmlbzeFbBj6AdAFW+ftvB1zMkH9h8ZySSicaWPWASVY7rsjO5SJdugPPGFGsz6LRO+er D9zfsWu+5soHfVqbR6cRizXYDbE61ydpnzcmkmoYL99TFl+Y4BOnVlTvWZyzJ4boX8TT Bl/w== X-Gm-Message-State: AC+VfDzkDK4hdRtJclHUqX/KYydSSLkhNI4A9iWaH3llK+YxvxaPLsKA kSUH1Yei9V4iLI/4HuSed5LtWg== X-Google-Smtp-Source: ACHHUZ44+AOI9mWDA0VX65/ESLRXKLOnscfmWt0mUNuMW3DNnCeVUO4F9Z4ifghSDalvpZuia1FTVw== X-Received: by 2002:a17:902:fa0f:b0:1a9:8ff5:af43 with SMTP id la15-20020a170902fa0f00b001a98ff5af43mr3207546plb.18.1683341280366; Fri, 05 May 2023 19:48:00 -0700 (PDT) Received: from GL4FX4PXWL.bytedance.net ([139.177.225.232]) by smtp.gmail.com with ESMTPSA id j17-20020a170902759100b001ab0672fc1fsm2421871pll.105.2023.05.05.19.47.57 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Fri, 05 May 2023 19:47:59 -0700 (PDT) From: Peng Zhang To: Liam.Howlett@oracle.com Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org, Peng Zhang Subject: [PATCH v2] maple_tree: Fix potential out-of-bounds access in mas_wr_end_piv() Date: Sat, 6 May 2023 10:47:52 +0800 Message-Id: <20230506024752.2550-1-zhangpeng.00@bytedance.com> X-Mailer: git-send-email 2.37.0 (Apple Git-136) MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Check the write offset end bounds before using it as the offset into the pivot array. This avoids a possible out-of-bounds access on the pivot array if the write extends to the last slot in the node, in which case the node maximum should be used as the end pivot. Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Peng Zhang Reviewed-by: Liam R. Howlett --- lib/maple_tree.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 110a36479dced..5a49327444d76 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -4263,11 +4263,13 @@ static inline bool mas_wr_slot_store(struct ma_wr_state *wr_mas) static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas) { - while ((wr_mas->mas->last > wr_mas->end_piv) && - (wr_mas->offset_end < wr_mas->node_end)) - wr_mas->end_piv = wr_mas->pivots[++wr_mas->offset_end]; + while ((wr_mas->offset_end < wr_mas->node_end) && + (wr_mas->mas->last > wr_mas->pivots[wr_mas->offset_end])) + wr_mas->offset_end++; - if (wr_mas->mas->last > wr_mas->end_piv) + if (wr_mas->offset_end < wr_mas->node_end) + wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end]; + else wr_mas->end_piv = wr_mas->mas->max; } @@ -4424,7 +4426,6 @@ static inline void *mas_wr_store_entry(struct ma_wr_state *wr_mas) } /* At this point, we are at the leaf node that needs to be altered. */ - wr_mas->end_piv = wr_mas->r_max; mas_wr_end_piv(wr_mas); if (!wr_mas->entry)