From nobody Fri Jun 19 00:56:17 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 995B8C433F5 for ; Mon, 11 Apr 2022 10:45:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345739AbiDKKsJ (ORCPT ); Mon, 11 Apr 2022 06:48:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345729AbiDKKsD (ORCPT ); Mon, 11 Apr 2022 06:48:03 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBEE4186FB for ; Mon, 11 Apr 2022 03:45:49 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id 2so14897075pjw.2 for ; Mon, 11 Apr 2022 03:45:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=cgk0yjKGyZZ3WohS+RmN42unOs/YYInKeZtRcK9rHyc=; b=gR7aCeFK8v+Ud8TJUkbFoMyayQnEYDODrBnCfGbeG+zb/RynV+cSpzceKrCZ5wMykZ dmJ1GCm/a3zMbg2EZrRMFm9rFK6SfVp585WTnBPAGnRhFkFdxq/Fi6o8ahj9YNhlKa1k tYejK/UOqD1IWv4LiIG72TIA0oT0endbHK/XAj4Qt5hlG//asSja7TYXrYOdBaV+iH83 Rs25nlpMwGJPWu+zM9ND3b8btzxciDcXgK4kFstlGu73V49WeVebIlsbvkHUSjbBsKeA VtuJyupg7BJOt8WIbFjM8OU8zt8gOg2WqRrHL9HNKC9GbrXj+kAibXOjG67rBu6KlGvW V1mA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=cgk0yjKGyZZ3WohS+RmN42unOs/YYInKeZtRcK9rHyc=; b=D8mypGMFuMAjnn3tquaOFUSTvRkOftjG4QzpvBmXfebBnmZzeDucU0qo6QKd8SH+hv ydxmp31dUjGX7AL7KHVsXct96VaY92rSlPUUKLTu+2S1NERuk0oF/K1j0GnMzhK0oTjs 3RA9ptwhBR1/MLvY9EWPW/sT/GiFST90sUK213XQ4xCrpD8KiOM7339gcuykxYEnjYH8 +CZHYlFJOQyF5PZoeGmrjdp4jMQMAQl8z+aF1CB+wHJ61xXVPAlDA08b6UsPJ5mRL1su 7E4OI72F1H/Jt9vVDhRMPoD5iGammYXzwUGRDfX7t7UCyls/IXjpmkNGCsNb4jDBicke xZ1A== X-Gm-Message-State: AOAM530VqZYhKEtTwGYQ/25MwrxfY65eQXasBFYPilzzBs8Zpj5vkBg1 WzkHZ6xEUcGnhrQalMrD7tU= X-Google-Smtp-Source: ABdhPJzw3WifQ58vmxssYy00TXa8ner2CIBlECSTkKcTdxtfk4IL9t+EkZ1GK3YfBLY9hzTzhgfAFA== X-Received: by 2002:a17:902:e74c:b0:158:5c47:9181 with SMTP id p12-20020a170902e74c00b001585c479181mr5317652plf.144.1649673949337; Mon, 11 Apr 2022 03:45:49 -0700 (PDT) Received: from fuzzserver.tsinghua.edu.cn ([166.111.139.106]) by smtp.gmail.com with ESMTPSA id s10-20020a63a30a000000b003987eaef296sm29086232pge.44.2022.04.11.03.45.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Apr 2022 03:45:48 -0700 (PDT) From: Zixuan Fu To: shaggy@kernel.org Cc: jfs-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com, Zixuan Fu , TOTE Robot Subject: [PATCH] fs: jfs: fix possible NULL pointer dereference in dbFree() Date: Mon, 11 Apr 2022 18:45:34 +0800 Message-Id: <20220411104534.744772-1-r33s3n6@gmail.com> X-Mailer: git-send-email 2.25.1 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" In our fault-injection testing, the variable "nblocks" in dbFree() can be zero when kmalloc_array() fails in dtSearch(). In this case, the variable "mp" in dbFree() would be NULL and then it is dereferenced in=20 "write_metapage(mp)". The failure log is listed as follows: [ 13.824137] BUG: kernel NULL pointer dereference, address: 0000000000000= 020 ... [ 13.827416] RIP: 0010:dbFree+0x5f7/0x910 [jfs] [ 13.834341] Call Trace: [ 13.834540] [ 13.834713] txFreeMap+0x7b4/0xb10 [jfs] [ 13.835038] txUpdateMap+0x311/0x650 [jfs] [ 13.835375] jfs_lazycommit+0x5f2/0xc70 [jfs] [ 13.835726] ? sched_dynamic_update+0x1b0/0x1b0 [ 13.836092] kthread+0x3c2/0x4a0 [ 13.836355] ? txLockFree+0x160/0x160 [jfs] [ 13.836763] ? kthread_unuse_mm+0x160/0x160 [ 13.837106] ret_from_fork+0x1f/0x30 [ 13.837402] ... This patch adds a NULL check of "mp" before "write_metapage(mp)" is called. Reported-by: TOTE Robot Signed-off-by: Zixuan Fu --- fs/jfs/jfs_dmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index d8502f4989d9..e75f31b81d63 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -385,7 +385,8 @@ int dbFree(struct inode *ip, s64 blkno, s64 nblocks) } =20 /* write the last buffer. */ - write_metapage(mp); + if (mp) + write_metapage(mp); =20 IREAD_UNLOCK(ipbmap); =20 --=20 2.25.1