[BUG] greybus: ODEBUG free-active-timer in gb_operation_sync_timeout()

[Farhad Alemi]

Hello,

As part of the kernel research at ASU's SEFCOM
lab, we hit the crash below. Crash reports can be found here:

  https://github.com/farhad-alemi/public_bug_reports/tree/main/165-warning-odebug-bug-in-gb-operation-sync-timeout/

  ODEBUG: free active (active state 0) object: ffff888014747a70 object
type: timer_list hint: gb_operation_timeout+0x0/0x100
drivers/greybus/operation.c:1265
  WARNING: lib/debugobjects.c:632 at
debug_check_no_obj_freed+0x3fd/0x540 lib/debugobjects.c:1156, CPU#1:
kworker/u8:3/10201
  Call Trace:
   kmem_cache_free+0xcb/0x4d0 mm/slub.c:6378
   gb_operation_sync_timeout+0x1c7/0x270 drivers/greybus/operation.c:1172
   gb_operation_sync include/linux/greybus/operation.h:203 [inline]
   gb_svc_dme_peer_get+0x10a/0x250 drivers/greybus/svc.c:428
   gb_interface_read_and_clear_init_status
drivers/greybus/interface.c:380 [inline]
   gb_interface_enable+0x146/0x900 drivers/greybus/interface.c:1075
   gb_module_register_interface drivers/greybus/module.c:162 [inline]
   gb_module_add+0x1b3/0x3d0 drivers/greybus/module.c:209

Our reproducer.c is available upon request.

Happy to test a patch if that would help.

Regards,