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 38d20c62903d669693a1869aa68c4dd5674e2544 upstream.
The race is between the handling of a new TCP connection and its disconnection. It leads to UAF on `struct tcp_transport` in ksmbd_tcp_new_connection() function.
Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-22991 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/connection.c | 6 ------ fs/smb/server/connection.h | 1 - fs/smb/server/transport_rdma.c | 11 ++++++----- fs/smb/server/transport_tcp.c | 13 +++++++------ 4 files changed, 13 insertions(+), 18 deletions(-)
--- a/fs/smb/server/connection.c +++ b/fs/smb/server/connection.c @@ -415,13 +415,7 @@ static void stop_sessions(void) again: down_read(&conn_list_lock); list_for_each_entry(conn, &conn_list, conns_list) { - struct task_struct *task; - t = conn->transport; - task = t->handler; - if (task) - ksmbd_debug(CONN, "Stop session handler %s/%d\n", - task->comm, task_pid_nr(task)); ksmbd_conn_set_exiting(conn); if (t->ops->shutdown) { up_read(&conn_list_lock); --- a/fs/smb/server/connection.h +++ b/fs/smb/server/connection.h @@ -135,7 +135,6 @@ struct ksmbd_transport_ops { struct ksmbd_transport { struct ksmbd_conn *conn; struct ksmbd_transport_ops *ops; - struct task_struct *handler; };
#define KSMBD_TCP_RECV_TIMEOUT (7 * HZ) --- a/fs/smb/server/transport_rdma.c +++ b/fs/smb/server/transport_rdma.c @@ -2039,6 +2039,7 @@ static bool rdma_frwr_is_supported(struc static int smb_direct_handle_connect_request(struct rdma_cm_id *new_cm_id) { struct smb_direct_transport *t; + struct task_struct *handler; int ret;
if (!rdma_frwr_is_supported(&new_cm_id->device->attrs)) { @@ -2056,11 +2057,11 @@ static int smb_direct_handle_connect_req if (ret) goto out_err;
- KSMBD_TRANS(t)->handler = kthread_run(ksmbd_conn_handler_loop, - KSMBD_TRANS(t)->conn, "ksmbd:r%u", - smb_direct_port); - if (IS_ERR(KSMBD_TRANS(t)->handler)) { - ret = PTR_ERR(KSMBD_TRANS(t)->handler); + handler = kthread_run(ksmbd_conn_handler_loop, + KSMBD_TRANS(t)->conn, "ksmbd:r%u", + smb_direct_port); + if (IS_ERR(handler)) { + ret = PTR_ERR(handler); pr_err("Can't start thread\n"); goto out_err; } --- a/fs/smb/server/transport_tcp.c +++ b/fs/smb/server/transport_tcp.c @@ -185,6 +185,7 @@ static int ksmbd_tcp_new_connection(stru struct sockaddr *csin; int rc = 0; struct tcp_transport *t; + struct task_struct *handler;
t = alloc_transport(client_sk); if (!t) { @@ -199,13 +200,13 @@ static int ksmbd_tcp_new_connection(stru goto out_error; }
- KSMBD_TRANS(t)->handler = kthread_run(ksmbd_conn_handler_loop, - KSMBD_TRANS(t)->conn, - "ksmbd:%u", - ksmbd_tcp_get_port(csin)); - if (IS_ERR(KSMBD_TRANS(t)->handler)) { + handler = kthread_run(ksmbd_conn_handler_loop, + KSMBD_TRANS(t)->conn, + "ksmbd:%u", + ksmbd_tcp_get_port(csin)); + if (IS_ERR(handler)) { pr_err("cannot start conn thread\n"); - rc = PTR_ERR(KSMBD_TRANS(t)->handler); + rc = PTR_ERR(handler); free_transport(t); } return rc;