From: Archie Pusaka <apusaka@xxxxxxxxxxxx> Currently l2cap_chan_set_defaults() reset chan->conf_state to zero. However, there is a flag CONF_NOT_COMPLETE which is set when creating the l2cap_chan. It is suggested that the flag should be cleared when l2cap_chan is ready, but when l2cap_chan_set_defaults() is called, l2cap_chan is not yet ready. Therefore, we must set this flag as the default. Example crash call trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0xc4/0x118 lib/dump_stack.c:56 panic+0x1c6/0x38b kernel/panic.c:117 __warn+0x170/0x1b9 kernel/panic.c:471 warn_slowpath_fmt+0xc7/0xf8 kernel/panic.c:494 debug_print_object+0x175/0x193 lib/debugobjects.c:260 debug_object_assert_init+0x171/0x1bf lib/debugobjects.c:614 debug_timer_assert_init kernel/time/timer.c:629 [inline] debug_assert_init kernel/time/timer.c:677 [inline] del_timer+0x7c/0x179 kernel/time/timer.c:1034 try_to_grab_pending+0x81/0x2e5 kernel/workqueue.c:1230 cancel_delayed_work+0x7c/0x1c4 kernel/workqueue.c:2929 l2cap_clear_timer+0x1e/0x41 include/net/bluetooth/l2cap.h:834 l2cap_chan_del+0x2d8/0x37e net/bluetooth/l2cap_core.c:640 l2cap_chan_close+0x532/0x5d8 net/bluetooth/l2cap_core.c:756 l2cap_sock_shutdown+0x806/0x969 net/bluetooth/l2cap_sock.c:1174 l2cap_sock_release+0x64/0x14d net/bluetooth/l2cap_sock.c:1217 __sock_release+0xda/0x217 net/socket.c:580 sock_close+0x1b/0x1f net/socket.c:1039 __fput+0x322/0x55c fs/file_table.c:208 ____fput+0x17/0x19 fs/file_table.c:244 task_work_run+0x19b/0x1d3 kernel/task_work.c:115 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0xe4c/0x204a kernel/exit.c:766 do_group_exit+0x291/0x291 kernel/exit.c:891 get_signal+0x749/0x1093 kernel/signal.c:2396 do_signal+0xa5/0xcdb arch/x86/kernel/signal.c:737 exit_to_usermode_loop arch/x86/entry/common.c:243 [inline] prepare_exit_to_usermode+0xed/0x235 arch/x86/entry/common.c:277 syscall_return_slowpath+0x3a7/0x3b3 arch/x86/entry/common.c:348 int_ret_from_sys_call+0x25/0xa3 Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx> Reported-by: syzbot+338f014a98367a08a114@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Alain Michaud <alainm@xxxxxxxxxxxx> Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx> --- net/bluetooth/l2cap_core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 374cc32d7138..59ab9689b37d 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -516,7 +516,9 @@ void l2cap_chan_set_defaults(struct l2cap_chan *chan) chan->flush_to = L2CAP_DEFAULT_FLUSH_TO; chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO; chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO; + chan->conf_state = 0; + set_bit(CONF_NOT_COMPLETE, &chan->conf_state); set_bit(FLAG_FORCE_ACTIVE, &chan->flags); } -- 2.31.0.rc2.261.g7f71774620-goog
