From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Pan Bian , Joe Perches , "Ernesto A . Fernandez" , Viacheslav Dubeyko , Andrew Morton , Linus Torvalds , Sasha Levin , linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 30/33] hfs: do not free node before using Date: Wed, 5 Dec 2018 04:51:28 -0500 Message-Id: <20181205095131.7685-30-sashal@kernel.org> In-Reply-To: <20181205095131.7685-1-sashal@kernel.org> References: <20181205095131.7685-1-sashal@kernel.org> List-ID: From: Pan Bian [ Upstream commit ce96a407adef126870b3f4a1b73529dd8aa80f49 ] hfs_bmap_free() frees the 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 the node only when it is never again used. Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.com Fixes: a1185ffa2fc ("HFS rewrite") Signed-off-by: Pan Bian Reviewed-by: Andrew Morton Cc: Joe Perches Cc: Ernesto A. Fernandez Cc: Viacheslav Dubeyko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/hfs/btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c index 1ab19e660e69..1ff5774a5382 100644 --- a/fs/hfs/btree.c +++ b/fs/hfs/btree.c @@ -328,13 +328,14 @@ 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; -- 2.17.1