A crash was reported by Wei Chen:
BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:tipc_conn_close+0x12/0x100
Call Trace:
tipc_topsrv_exit_net+0x139/0x320
ops_exit_list.isra.9+0x49/0x80
cleanup_net+0x31a/0x540
process_one_work+0x3fa/0x9f0
worker_thread+0x42/0x5c0
It was caused by !con->sock in tipc_conn_close(). In tipc_topsrv_accept(),
con is allocated in conn_idr then its sock is set:
con = tipc_conn_alloc();
... <----[1]
con->sock = newsock;
If tipc_conn_close() is called in anytime of [1], the null-pointer-def
is triggered by con->sock->sk due to con->sock is not yet set.
This patch fixes it by moving the con->sock setting to tipc_conn_alloc()
under s->idr_lock. So that con->sock can never be NULL when getting the
con from s->conn_idr. It will be also safer to move con->server and flag
CF_CONNECTED setting under s->idr_lock, as they should all be set before
tipc_conn_alloc() is called.
Fixes: c5fa7b3cf3 ("tipc: introduce new TIPC server infrastructure")
Reported-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
0e5d56c64a