Commit d2139ee7 authored by Pan Bian's avatar Pan Bian Committed by Greg Kroah-Hartman
Browse files

exportfs: do not read dentry after free

[ Upstream commit 2084ac6c505a58f7efdec13eba633c6aaa085ca5 ]

The function dentry_connected calls dput(dentry) to drop the previously
acquired reference to dentry. In this case, dentry can be released.
After that, IS_ROOT(dentry) checks the condition
(dentry == dentry->d_parent), which may result in a use-after-free bug.
This patch directly compares dentry with its parent obtained before
dropping the reference.

Fixes: a056cc89

("exportfs: stop retrying once we race with
Signed-off-by: default avatarPan Bian <>
Signed-off-by: default avatarAl Viro <>
Signed-off-by: default avatarSasha Levin <>
parent 476a6073
......@@ -76,7 +76,7 @@ static bool dentry_connected(struct dentry *dentry)
struct dentry *parent = dget_parent(dentry);
if (IS_ROOT(dentry)) {
if (dentry == parent) {
return false;
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment