From: youngjun <her0gyugyu@xxxxxxxxx>
commit 24f14009b8f1754ec2ae4c168940c01259b0f88a upstream.
When "ovl_is_inuse" true case, trap inode reference not put. plus adding
the comment explaining sequence of ovl_is_inuse after ovl_setup_trap.
Fixes: 0be0bfd2de9d ("ovl: fix regression caused by overlapping layers detection")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.19+
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: youngjun <her0gyugyu@xxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/overlayfs/super.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1356,14 +1356,23 @@ static int ovl_get_lower_layers(struct s
if (err < 0)
goto out;
+ /*
+ * Check if lower root conflicts with this overlay layers before
+ * checking if it is in-use as upperdir/workdir of "another"
+ * mount, because we do not bother to check in ovl_is_inuse() if
+ * the upperdir/workdir is in fact in-use by our
+ * upperdir/workdir.
+ */
err = ovl_setup_trap(sb, stack[i].dentry, &trap, "lowerdir");
if (err)
goto out;
if (ovl_is_inuse(stack[i].dentry)) {
err = ovl_report_in_use(ofs, "lowerdir");
- if (err)
+ if (err) {
+ iput(trap);
goto out;
+ }
}
mnt = clone_private_mount(&stack[i]);
