[PATCH 4.9 18/78] hfs: prevent crash on exit from failed search

From: Greg Kroah-Hartman
Date: Thu Sep 13 2018 - 09:35:33 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: "Ernesto A. Fernáez" <ernesto.mnd.fernandez@xxxxxxxxx>

[ Upstream commit dc2572791d3a41bab94400af2b6bca9d71ccd303 ]

hfs_find_exit() expects fd->bnode to be NULL after a search has failed.
hfs_brec_insert() may instead set it to an error-valued pointer. Fix
this to prevent a crash.

Link: http://lkml.kernel.org/r/53d9749a029c41b4016c495fc5838c9dba3afc52.1530294815.git.ernesto.mnd.fernandez@xxxxxxxxx
Signed-off-by: Ernesto A. FernÃndez <ernesto.mnd.fernandez@xxxxxxxxx>
Cc: Anatoly Trosinenko <anatoly.trosinenko@xxxxxxxxx>
Cc: Viacheslav Dubeyko <slava@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/hfs/brec.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/fs/hfs/brec.c
+++ b/fs/hfs/brec.c
@@ -74,9 +74,10 @@ int hfs_brec_insert(struct hfs_find_data
if (!fd->bnode) {
if (!tree->root)
hfs_btree_inc_height(tree);
- fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
- if (IS_ERR(fd->bnode))
- return PTR_ERR(fd->bnode);
+ node = hfs_bnode_find(tree, tree->leaf_head);
+ if (IS_ERR(node))
+ return PTR_ERR(node);
+ fd->bnode = node;
fd->record = -1;
}
new_node = NULL;