From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
commit 30210947a343b6b3ca13adc9bfc88e1543e16dd5 upstream.
There is UAF issue under cocurrent smb2 tree disconnect.
This patch introduce TREE_CONN_EXPIRE flags for tcon to avoid cocurrent
access.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: zdi-disclosures@xxxxxxxxxxxxxx # ZDI-CAN-20592
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ksmbd/mgmt/tree_connect.c | 10 +++++++++-
fs/ksmbd/mgmt/tree_connect.h | 3 +++
fs/ksmbd/smb2pdu.c | 3 ++-
3 files changed, 14 insertions(+), 2 deletions(-)
--- a/fs/ksmbd/mgmt/tree_connect.c
+++ b/fs/ksmbd/mgmt/tree_connect.c
@@ -109,7 +109,15 @@ int ksmbd_tree_conn_disconnect(struct ks
struct ksmbd_tree_connect *ksmbd_tree_conn_lookup(struct ksmbd_session *sess,
unsigned int id)
{
- return xa_load(&sess->tree_conns, id);
+ struct ksmbd_tree_connect *tcon;
+
+ tcon = xa_load(&sess->tree_conns, id);
+ if (tcon) {
+ if (test_bit(TREE_CONN_EXPIRE, &tcon->status))
+ tcon = NULL;
+ }
+
+ return tcon;
}
struct ksmbd_share_config *ksmbd_tree_conn_share(struct ksmbd_session *sess,
--- a/fs/ksmbd/mgmt/tree_connect.h
+++ b/fs/ksmbd/mgmt/tree_connect.h
@@ -14,6 +14,8 @@ struct ksmbd_share_config;
struct ksmbd_user;
struct ksmbd_conn;
+#define TREE_CONN_EXPIRE 1
+
struct ksmbd_tree_connect {
int id;
@@ -25,6 +27,7 @@ struct ksmbd_tree_connect {
int maximal_access;
bool posix_extensions;
+ unsigned long status;
};
struct ksmbd_tree_conn_status {
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -2055,11 +2055,12 @@ int smb2_tree_disconnect(struct ksmbd_wo
ksmbd_debug(SMB, "request\n");
- if (!tcon) {
+ if (!tcon || test_and_set_bit(TREE_CONN_EXPIRE, &tcon->status)) {
struct smb2_tree_disconnect_req *req =
smb2_get_msg(work->request_buf);
ksmbd_debug(SMB, "Invalid tid %d\n", req->hdr.Id.SyncId.TreeId);
+
rsp->hdr.Status = STATUS_NETWORK_NAME_DELETED;
smb2_set_err_rsp(work);
return 0;
