Hello, I've hit the following warning while running syzkaller fuzzer: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 17409 at kernel/workqueue.c:3968 destroy_workqueue+0x172/0x550() Modules linked in: CPU: 2 PID: 17409 Comm: syz-executor Not tainted 4.5.0-rc1+ #283 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 00000000ffffffff ffff88003665f8a0 ffffffff8299a06d 0000000000000000 ffff88003599c740 ffffffff8643f0c0 ffff88003665f8e0 ffffffff8134fcf9 ffffffff8139d4c2 ffffffff8643f0c0 0000000000000f80 ffff8800630c5ae8 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff8299a06d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff8134fcf9>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff8134ff29>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8139d4c2>] destroy_workqueue+0x172/0x550 kernel/workqueue.c:3968 [<ffffffff85a714a4>] hci_unregister_dev+0x264/0x700 net/bluetooth/hci_core.c:3162 [<ffffffff84595ce6>] vhci_release+0x76/0xe0 drivers/bluetooth/hci_vhci.c:341 [<ffffffff817b2376>] __fput+0x236/0x780 fs/file_table.c:208 [<ffffffff817b2945>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff813ad760>] task_work_run+0x170/0x210 kernel/task_work.c:115 [< inline >] exit_task_work include/linux/task_work.h:21 [<ffffffff81358da5>] do_exit+0x8b5/0x2c60 kernel/exit.c:748 [<ffffffff8135b2c8>] do_group_exit+0x108/0x330 kernel/exit.c:878 [<ffffffff8137e434>] get_signal+0x5e4/0x14f0 kernel/signal.c:2307 [<ffffffff811a1db3>] do_signal+0x83/0x1c90 arch/x86/kernel/signal.c:712 [<ffffffff81006685>] exit_to_usermode_loop+0x1a5/0x210 arch/x86/entry/common.c:247 [< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:282 [<ffffffff810084ea>] syscall_return_slowpath+0x2ba/0x340 arch/x86/entry/common.c:344 [<ffffffff863597a2>] int_ret_from_sys_call+0x25/0x9f arch/x86/entry/entry_64.S:281 ---[ end trace f627386faee7426f ]--- Unfortunately I cannot reproduce it in a controlled environment, but I've hit it twice in different VMs. So maybe if you see something obvious there. Is it possible that something is submitted into the workqueue between it is drained and destroyed in hci_unregister_dev? On commit 92e963f50fc74041b5e9e744c330dca48e04f08d (Jan 24). -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
