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authorPan Bian <bianpan2016@163.com>2018-11-30 14:09:14 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-11-30 14:56:14 -0800
commitce96a407adef126870b3f4a1b73529dd8aa80f49 (patch)
tree09b2993b6d5f461e8e1045651661f59f69547063 /fs
parent94570a413f01dda8938d980d36814eee295d2a58 (diff)
downloadlinux-ce96a407adef126870b3f4a1b73529dd8aa80f49.tar.gz
hfs: do not free node before using
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 <bianpan2016@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/hfs/btree.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
index 98b96ffb95ed..19017d296173 100644
--- a/fs/hfs/btree.c
+++ b/fs/hfs/btree.c
@@ -338,13 +338,14 @@ 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;