[PATCH 4.14 024/124] ovl: fix error handling in ovl_verify_set_fh()

Greg Kroah-Hartman
2018-11-19T16:47:53Z

From: Amir Goldstein <amir73il@gmail.com>

commit babf4770be0adc69e6d2de150f4040f175e24beb upstream.

We hit a BUG on kfree of an ERR_PTR()...

Reported-by: syzbot+ff03fe05c717b82502d0@syzkaller.appspotmail.com
Fixes: 8b88a2e64036 ("ovl: verify upper root dir matches lower root dir")
Cc: <stable@vger.kernel.org> # v4.13
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/overlayfs/namei.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -368,8 +368,10 @@ int ovl_verify_origin(struct dentry *den

fh = ovl_encode_fh(origin, is_upper);
err = PTR_ERR(fh);
- if (IS_ERR(fh))
+ if (IS_ERR(fh)) {
+ fh = NULL;
goto fail;
+ }

err = ovl_verify_origin_fh(dentry, fh);
if (set && err == -ENODATA)