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authorNamjae Jeon <linkinjeon@kernel.org>2023-05-03 08:51:12 +0900
committerSteve French <stfrench@microsoft.com>2023-05-03 23:03:02 -0500
commit30210947a343b6b3ca13adc9bfc88e1543e16dd5 (patch)
treeb975ba955a52288885c013b107e7114523c3c24b
parentabcc506a9a71976a8b4c9bf3ee6efd13229c1e19 (diff)
ksmbd: fix racy issue under cocurrent smb2 tree disconnect
There is UAF issue under cocurrent smb2 tree disconnect. This patch introduce TREE_CONN_EXPIRE flags for tcon to avoid cocurrent access. Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-20592 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
-rw-r--r--fs/ksmbd/mgmt/tree_connect.c10
-rw-r--r--fs/ksmbd/mgmt/tree_connect.h3
-rw-r--r--fs/ksmbd/smb2pdu.c3
3 files changed, 14 insertions, 2 deletions
diff --git a/fs/ksmbd/mgmt/tree_connect.c b/fs/ksmbd/mgmt/tree_connect.c
index aa9c138d5851..f07a05f37651 100644
--- a/fs/ksmbd/mgmt/tree_connect.c
+++ b/fs/ksmbd/mgmt/tree_connect.c
@@ -109,7 +109,15 @@ int ksmbd_tree_conn_disconnect(struct ksmbd_session *sess,
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,
diff --git a/fs/ksmbd/mgmt/tree_connect.h b/fs/ksmbd/mgmt/tree_connect.h
index 0f97ddc1e39c..700df36cf3e3 100644
--- 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 {
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 0ca1c5daf60a..cb93fd231f4e 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -2053,11 +2053,12 @@ int smb2_tree_disconnect(struct ksmbd_work *work)
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;