[PATCH 4.2.y-ckt 65/98] ovl: fix getcwd() failure after unsuccessful rmdir

Kamal Mostafa
2016-03-15T23:30:59Z

From: Rui Wang <rui.y.wang@intel.com>

commit ce9113bbcbf45a57c082d6603b9a9f342be3ef74 upstream.

ovl_remove_upper() should do d_drop() only after it successfully
removes the dir, otherwise a subsequent getcwd() system call will
fail, breaking userspace programs.

This is to fix: https://bugzilla.kernel.org/show_bug.cgi?id=110491

Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Reviewed-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
fs/overlayfs/dir.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 692ceda..36d6a5b 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -618,7 +618,8 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
* sole user of this dentry. Too tricky... Just unhash for
* now.
*/
- d_drop(dentry);
+ if (!err)
+ d_drop(dentry);
mutex_unlock(&dir->i_mutex);

return err;
--
2.7.0