bisecting fixing commit since c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a building syzkaller on 80a0690249dc4dbbbed95ba197192b99c73694c5 testing commit c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a with gcc (GCC) 8.4.1 20210217 kernel signature: 309329f3cb83491788a34c4254218dd4fd125e3e5ccdb40b0dd87cc675be7d5e run #0: crashed: general protection fault in __queue_work run #1: crashed: WARNING: ODEBUG bug in bt_host_release run #2: crashed: WARNING: ODEBUG bug in bt_host_release run #3: crashed: WARNING: ODEBUG bug in bt_host_release run #4: crashed: WARNING: ODEBUG bug in bt_host_release run #5: crashed: KASAN: use-after-free Read in __queue_work run #6: crashed: general protection fault in __queue_work run #7: crashed: WARNING: ODEBUG bug in bt_host_release run #8: crashed: KASAN: use-after-free Read in __queue_work run #9: crashed: KASAN: use-after-free Read in __queue_work run #10: crashed: WARNING: ODEBUG bug in bt_host_release run #11: OK run #12: OK run #13: OK run #14: crashed: KASAN: use-after-free Read in __queue_work run #15: OK run #16: OK run #17: OK run #18: OK run #19: OK testing current HEAD 89698becf06d341a700913c3d89ce2a914af69a2 testing commit 89698becf06d341a700913c3d89ce2a914af69a2 with gcc (GCC) 10.2.1 20210217 kernel signature: 58fa2f554f9396fdec52d90975dd3c7aeddc4d4893883078a21c84cba8569182 run #0: crashed: general protection fault in __queue_work run #1: crashed: KASAN: use-after-free Read in __queue_work run #2: crashed: WARNING: ODEBUG bug in bt_host_release run #3: crashed: WARNING: ODEBUG bug in bt_host_release run #4: crashed: WARNING: ODEBUG bug in bt_host_release run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK revisions tested: 2, total time: 30m28.499788862s (build: 12m8.346463472s, test: 17m27.723952529s) the crash still happens on HEAD commit msg: Merge tag 'm68knommu-for-v5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu crash: WARNING: ODEBUG bug in bt_host_release ------------[ cut here ]------------ ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x90 arch/x86/include/asm/paravirt.h:658 WARNING: CPU: 0 PID: 12083 at lib/debugobjects.c:505 debug_print_object+0x160/0x250 lib/debugobjects.c:505 Modules linked in: CPU: 0 PID: 12083 Comm: syz-executor.1 Not tainted 5.12.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_print_object+0x160/0x250 lib/debugobjects.c:505 Code: dd 80 a4 12 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 bf 00 00 00 48 8b 14 dd 80 a4 12 88 48 c7 c7 a0 99 12 88 e8 e5 07 eb 03 <0f> 0b 83 05 c3 a8 e6 06 01 48 83 c4 20 5b 5d 41 5c 41 5d c3 48 89 RSP: 0018:ffffc90004c97bc8 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000004 RDI: fffff52000992f6b RBP: 0000000000000001 R08: 0000000000000001 R09: ffff8881f642095b R10: ffffed103ec8412b R11: 657461747320654f R12: ffffffff87ccede0 R13: ffffffff815bf330 R14: dead000000000100 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056094d2db908 CR3: 0000000102e20000 CR4: 0000000000350ef0 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:987 [inline] debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1018 kfree+0xf7/0x2d0 mm/slab.c:3795 bt_host_release+0xc/0x20 net/bluetooth/hci_sysfs.c:86 device_release+0x93/0x200 drivers/base/core.c:2108 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0xf6/0x1d0 lib/kobject.c:753 vhci_release+0x6a/0xd0 drivers/bluetooth/hci_vhci.c:341 __fput+0x209/0x870 fs/file_table.c:280 task_work_run+0xc0/0x160 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xac8/0x25b0 kernel/exit.c:825 do_group_exit+0xe7/0x290 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x35/0x40 kernel/exit.c:931 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x464769 Code: Unable to access opcode bytes at RIP 0x46473f. RSP: 002b:00007ffea5fe5788 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00000000000000e6 RCX: 0000000000464769 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 00000000004ae1d2 R08: 000000000000000b R09: 00000000000469c0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000046cec R14: 00000000000469c0 R15: 0000000000000005 irq event stamp: 1073114 hardirqs last enabled at (1073113): [] kfree+0x22c/0x2d0 mm/slab.c:3797 hardirqs last disabled at (1073114): [] kfree+0x136/0x2d0 mm/slab.c:3786 softirqs last enabled at (1062900): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last enabled at (1062900): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last enabled at (1062900): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 softirqs last disabled at (1062881): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last disabled at (1062881): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last disabled at (1062881): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 ---[ end trace 065a3c68b9a24670 ]---