6.1-stable review patch. If anyone has any objections, please let me know.
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From: Namjae Jeon linkinjeon@kernel.org
commit b95629435b84b9ecc0c765995204a4d8a913ed52 upstream.
Increment the session reference count within the lock for lookup to avoid racy issue with session expire.
Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-25737 Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/server/auth.c | 2 ++ fs/smb/server/mgmt/user_session.c | 6 +++++- fs/smb/server/server.c | 4 ++-- fs/smb/server/smb2pdu.c | 27 ++++++++++++++------------- 4 files changed, 23 insertions(+), 16 deletions(-)
--- a/fs/smb/server/auth.c +++ b/fs/smb/server/auth.c @@ -1010,6 +1010,8 @@ static int ksmbd_get_encryption_key(stru
ses_enc_key = enc ? sess->smb3encryptionkey : sess->smb3decryptionkey; + if (enc) + ksmbd_user_session_get(sess); memcpy(key, ses_enc_key, SMB3_ENC_DEC_KEY_SIZE);
return 0; --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -262,8 +262,10 @@ struct ksmbd_session *ksmbd_session_look
down_read(&conn->session_lock); sess = xa_load(&conn->sessions, id); - if (sess) + if (sess) { sess->last_active = jiffies; + ksmbd_user_session_get(sess); + } up_read(&conn->session_lock); return sess; } @@ -274,6 +276,8 @@ struct ksmbd_session *ksmbd_session_look
down_read(&sessions_table_lock); sess = __session_lookup(id); + if (sess) + ksmbd_user_session_get(sess); up_read(&sessions_table_lock);
return sess; --- a/fs/smb/server/server.c +++ b/fs/smb/server/server.c @@ -241,14 +241,14 @@ send: if (work->tcon) ksmbd_tree_connect_put(work->tcon); smb3_preauth_hash_rsp(work); - if (work->sess) - ksmbd_user_session_put(work->sess); if (work->sess && work->sess->enc && work->encrypted && conn->ops->encrypt_resp) { rc = conn->ops->encrypt_resp(work); if (rc < 0) conn->ops->set_rsp_status(work, STATUS_DATA_ERROR); } + if (work->sess) + ksmbd_user_session_put(work->sess);
ksmbd_conn_write(work); } --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -66,8 +66,10 @@ static inline bool check_session_id(stru return false;
sess = ksmbd_session_lookup_all(conn, id); - if (sess) + if (sess) { + ksmbd_user_session_put(sess); return true; + } pr_err("Invalid user session id: %llu\n", id); return false; } @@ -604,10 +606,8 @@ int smb2_check_user_session(struct ksmbd
/* Check for validity of user session */ work->sess = ksmbd_session_lookup_all(conn, sess_id); - if (work->sess) { - ksmbd_user_session_get(work->sess); + if (work->sess) return 1; - } ksmbd_debug(SMB, "Invalid user session, Uid %llu\n", sess_id); return -ENOENT; } @@ -1720,29 +1720,35 @@ int smb2_sess_setup(struct ksmbd_work *w
if (conn->dialect != sess->dialect) { rc = -EINVAL; + ksmbd_user_session_put(sess); goto out_err; }
if (!(req->hdr.Flags & SMB2_FLAGS_SIGNED)) { rc = -EINVAL; + ksmbd_user_session_put(sess); goto out_err; }
if (strncmp(conn->ClientGUID, sess->ClientGUID, SMB2_CLIENT_GUID_SIZE)) { rc = -ENOENT; + ksmbd_user_session_put(sess); goto out_err; }
if (sess->state == SMB2_SESSION_IN_PROGRESS) { rc = -EACCES; + ksmbd_user_session_put(sess); goto out_err; }
if (sess->state == SMB2_SESSION_EXPIRED) { rc = -EFAULT; + ksmbd_user_session_put(sess); goto out_err; } + ksmbd_user_session_put(sess);
if (ksmbd_conn_need_reconnect(conn)) { rc = -EFAULT; @@ -1750,7 +1756,8 @@ int smb2_sess_setup(struct ksmbd_work *w goto out_err; }
- if (ksmbd_session_lookup(conn, sess_id)) { + sess = ksmbd_session_lookup(conn, sess_id); + if (!sess) { rc = -EACCES; goto out_err; } @@ -1761,7 +1768,6 @@ int smb2_sess_setup(struct ksmbd_work *w }
conn->binding = true; - ksmbd_user_session_get(sess); } else if ((conn->dialect < SMB30_PROT_ID || server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL) && (req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) { @@ -1788,7 +1794,6 @@ int smb2_sess_setup(struct ksmbd_work *w }
conn->binding = false; - ksmbd_user_session_get(sess); } work->sess = sess;
@@ -2207,9 +2212,9 @@ err_out: int smb2_session_logoff(struct ksmbd_work *work) { struct ksmbd_conn *conn = work->conn; + struct ksmbd_session *sess = work->sess; struct smb2_logoff_req *req; struct smb2_logoff_rsp *rsp; - struct ksmbd_session *sess; u64 sess_id; int err;
@@ -2231,11 +2236,6 @@ int smb2_session_logoff(struct ksmbd_wor ksmbd_close_session_fds(work); ksmbd_conn_wait_idle(conn, sess_id);
- /* - * Re-lookup session to validate if session is deleted - * while waiting request complete - */ - sess = ksmbd_session_lookup_all(conn, sess_id); if (ksmbd_tree_conn_session_logoff(sess)) { ksmbd_debug(SMB, "Invalid tid %d\n", req->hdr.Id.SyncId.TreeId); rsp->hdr.Status = STATUS_NETWORK_NAME_DELETED; @@ -8682,6 +8682,7 @@ int smb3_decrypt_req(struct ksmbd_work * le64_to_cpu(tr_hdr->SessionId)); return -ECONNABORTED; } + ksmbd_user_session_put(sess);
iov[0].iov_base = buf; iov[0].iov_len = sizeof(struct smb2_transform_hdr) + 4;