An HFS+ filesystem can be mounted read-only without having a metadata
directory, which is needed to support hardlinks. But if the catalog data
is corrupted, a directory lookup may still find dentries claiming to be
hardlinks.
hfsplus_lookup() does check that ->hidden_dir is not NULL in such a
situation, but mistakenly does so after dereferencing it for the first
time. Reorder this check to prevent a crash.
Reported-by: Wen Xu <wen.xu@xxxxxxxxxx>
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@xxxxxxxxx>
---
fs/hfsplus/dir.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index b5254378f011..cd017d7dbdfa 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -78,13 +78,13 @@ static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
cpu_to_be32(HFSP_HARDLINK_TYPE) &&
entry.file.user_info.fdCreator ==
cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
+ HFSPLUS_SB(sb)->hidden_dir &&
(entry.file.create_date ==
HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
create_date ||
entry.file.create_date ==
HFSPLUS_I(d_inode(sb->s_root))->
- create_date) &&
- HFSPLUS_SB(sb)->hidden_dir) {
+ create_date)) {
struct qstr str;
char name[32];
--
2.11.0
