From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A69DC43603 for ; Tue, 17 Dec 2019 13:52:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE01D20716 for ; Tue, 17 Dec 2019 13:52:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bjOyv4WF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728627AbfLQNwg (ORCPT ); Tue, 17 Dec 2019 08:52:36 -0500 Received: from mail-pl1-f196.google.com ([209.85.214.196]:46967 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728388AbfLQNwg (ORCPT ); Tue, 17 Dec 2019 08:52:36 -0500 Received: by mail-pl1-f196.google.com with SMTP id y8so146319pll.13 for ; Tue, 17 Dec 2019 05:52:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=4Ab3Q/X4ZX5gMws9nUNXBeFR4zcomqzcsyRHhrq8jyw=; b=bjOyv4WFNA4Oiymym030hvCTlXDF88KMh8GhOROZW1CBvNWjeEu7md9vnE2vrZU2DH eijW5Zxcylr10kqvF7gxoPPnxI/oNVp3NDQ9QDAOT/hlaKFBKCwEqMnS/lAHvFfI9+Tf 5uiFyBRmQI6dcgpafCAxYmxoK6OGOU5pD6m7aiirOkUDVXkNqHlEexV6RXhMa7IuMH29 omWFCSFF6Sqnui+mmfa6bbchqDIVjg3vr86PyR9DHuNEvyPMtebB4EMHyUnd7ONy/ZmU sqL7MJzUEMUga2WjtTjUqIUEjklL510v4ADYm/+0jXnczO4vsOzQWDPwdQ1ZywAZ4RB0 qZdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=4Ab3Q/X4ZX5gMws9nUNXBeFR4zcomqzcsyRHhrq8jyw=; b=DZMnPub3pe2dh2uvatHG4thkUib9j+yLRJ3AQpBU2gBBGA/Jll/L5GCUdLDkpsScKA vKC/wIRxEG8ByIt5tj/epMlIEeEbh1uAsvV8uwp9+o55ljOKvwhvg5HrUoMMeYNaMEWV kV/Kz7P+eqKmrgpf3OTzyJIsL5uQ/yp/5lmuzb3GwEzv3C2N47xg2pTWXJuEFeBfTZYv /p5Ci06W3YkiICG+GtnLikSB9DmtV36Yv1es1xPC0+SmeIUouukQLWnFPbjakvEExxOy 53WBYfFy4we7nKrJTbr3G6PG77NiQu8nNzZSUD7QS6iRqLXhU0rkzTH3XB5aq07AUwZT 80PQ== X-Gm-Message-State: APjAAAXz4Hxq1qtcngArECWRmXUkXC9htN7FdGYAP2L6w0khqZOqXATx 14n7jGyXjzE0qwrtylfo/94= X-Google-Smtp-Source: APXvYqwg7iJqE7pkEx8c34mv/h5j38/Pvrmvpcu6TQkHXieFxOzdarytJCM8d0HbKBYvVOBk6zJV2w== X-Received: by 2002:a17:902:bf0b:: with SMTP id bi11mr2085843plb.282.1576590755583; Tue, 17 Dec 2019 05:52:35 -0800 (PST) Received: from oslab.tsinghua.edu.cn ([166.111.139.172]) by smtp.gmail.com with ESMTPSA id k1sm18091229pgq.70.2019.12.17.05.52.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Dec 2019 05:52:35 -0800 (PST) From: Jia-Ju Bai To: dwmw2@infradead.org, richard@nod.at Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] fs: jffs2: fix possible sleep-in-atomic-context bugs Date: Tue, 17 Dec 2019 21:51:43 +0800 Message-Id: <20191217135143.12875-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The filesystem may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: fs/jffs2/malloc.c, 188: kmem_cache_alloc(GFP_KERNEL) in jffs2_alloc_refblock fs/jffs2/malloc.c, 221: jffs2_alloc_refblock in jffs2_prealloc_raw_node_refs fs/jffs2/wbuf.c, 164: jffs2_prealloc_raw_node_refs in jffs2_block_refile fs/jffs2/wbuf.c, 291: jffs2_block_refile in jffs2_wbuf_recover fs/jffs2/wbuf.c, 287: spin_lock in jffs2_wbuf_recover fs/jffs2/malloc.c, 188: kmem_cache_alloc(GFP_KERNEL) in jffs2_alloc_refblock fs/jffs2/malloc.c, 221: jffs2_alloc_refblock in jffs2_prealloc_raw_node_refs fs/jffs2/wbuf.c, 164: jffs2_prealloc_raw_node_refs in jffs2_block_refile fs/jffs2/wbuf.c, 927: jffs2_block_refile in jffs2_flash_writev fs/jffs2/wbuf.c, 924: spin_lock in jffs2_flash_writev kmem_cache_alloc(GFP_KERNEL) can sleep at runtime. To fix these possible bugs, GFP_KERNEL is replaced with GFP_ATOMIC for kmem_cache_alloc(). These bugs are found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai --- fs/jffs2/malloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/jffs2/malloc.c b/fs/jffs2/malloc.c index ce1189793288..66496ef09716 100644 --- a/fs/jffs2/malloc.c +++ b/fs/jffs2/malloc.c @@ -185,7 +185,7 @@ static struct jffs2_raw_node_ref *jffs2_alloc_refblock(void) { struct jffs2_raw_node_ref *ret; - ret = kmem_cache_alloc(raw_node_ref_slab, GFP_KERNEL); + ret = kmem_cache_alloc(raw_node_ref_slab, GFP_ATOMIC); if (ret) { int i = 0; for (i=0; i < REFS_PER_BLOCK; i++) { -- 2.17.1