The patch titled
Subject: hfs: do not free node before using
has been added to the -mm tree. Its filename is
hfs-do-not-free-node-before-using.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/hfs-do-not-free-node-before-using.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/hfs-do-not-free-node-before-using.patch
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------------------------------------------------------
From: Pan Bian <bianpan2016@xxxxxxx>
Subject: 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@xxxxxxx
Fixes: d614267329f("hfs/hfsplus: convert printks to pr_<level>")
Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/fs/hfs/btree.c~hfs-do-not-free-node-before-using
+++ a/fs/hfs/btree.c
@@ -338,13 +338,14 @@ void hfs_bmap_free(struct hfs_bnode *nod
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;
_
Patches currently in -mm which might be from bianpan2016@xxxxxxx are
hfs-do-not-free-node-before-using.patch
