From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from m12-13.163.com ([220.181.12.13]:60059 "EHLO m12-13.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725940AbeKXUpb (ORCPT ); Sat, 24 Nov 2018 15:45:31 -0500 From: Pan Bian To: Andrew Morton , ernesto.mnd.fernandez@gmail.com Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH 1/1] hfsplus: do not free node before using Date: Sat, 24 Nov 2018 17:57:21 +0800 Message-Id: <1543053441-66942-1-git-send-email-bianpan2016@163.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: The function hfs_bmap_free frees node via hfs_bnode_put(node). However, it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees node only when it is never used. Signed-off-by: Pan Bian --- fs/hfsplus/btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/hfsplus/btree.c b/fs/hfsplus/btree.c index 236efe5..66774f4 100644 --- a/fs/hfsplus/btree.c +++ b/fs/hfsplus/btree.c @@ -466,14 +466,15 @@ void hfs_bmap_free(struct hfs_bnode *node) nidx -= len * 8; i = node->next; - hfs_bnode_put(node); if (!i) { /* panic */; pr_crit("unable to free bnode %u. " "bmap not found!\n", node->this); + hfs_bnode_put(node); return; } + hfs_bnode_put(node); node = hfs_bnode_find(tree, i); if (IS_ERR(node)) return; -- 2.7.4