Hi The customizations are related to driver fuzzing. We added some more descriptions of USB driver & narrowed the constraints (targeted fuzzing). And sorry about I have not much time to make patches of these bugs. On Fri, Oct 18, 2019 at 2:33 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > > On Wed, Oct 16, 2019 at 11:59 AM zzoru <zzoru007@xxxxxxxxx> wrote: > > > > We found the following crash on Linux 5.4-rc1 (Not patched in currnet > > HEAD commit 3b1f00aceb7a67bf079a5a64aa5c6baf78a8f442) > > with our customized syzkaller. > > Hi zzoru, > > Do you mind sharing what customizations you did to syzkaller? Are > these related to USB? I've noticed several reports were related to USB > subsystem. > > > ODEBUG: assert_init not available (active state 0) object type: > > timer_list hint: 0x0 > > WARNING: CPU: 0 PID: 141 at linux/lib/debugobjects.c:484 > > debug_print_object+0x15e/0x220 linux/lib/debugobjects.c:481 > > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 0 PID: 141 Comm: kworker/0:3 Not tainted 5.4.0-rc1 #5 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 > > Workqueue: usb_hub_wq hub_event > > Call Trace: > > __dump_stack linux/lib/dump_stack.c:77 [inline] > > dump_stack+0x7c/0xbb linux/lib/dump_stack.c:113 > > panic+0x205/0x48e linux/kernel/panic.c:220 > > __warn+0x19c/0x1c0 linux/kernel/panic.c:581 > > report_bug+0x1a9/0x2b0 linux/lib/bug.c:195 > > fixup_bug.part.11+0x32/0x80 linux/arch/x86/kernel/traps.c:179 > > fixup_bug linux/arch/x86/include/asm/irqflags.h:54 [inline] > > do_error_trap+0xf5/0x160 linux/arch/x86/kernel/traps.c:272 > > do_invalid_op+0x31/0x40 linux/arch/x86/kernel/traps.c:291 > > invalid_op+0x23/0x30 linux/arch/x86/entry/entry_64.S:1028 > > RIP: 0010:debug_print_object+0x15e/0x220 linux/lib/debugobjects.c:481 > > Code: 3c dd 80 05 9a 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7f 48 8b > > 14 dd 80 05 9a 85 4c 89 ee 48 c7 c7 00 fb 99 85 e8 d2 a7 43 ff <0f> 0b > > 83 05 cd bd 70 05 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3 > > RSP: 0018:ffff888017017668 EFLAGS: 00010282 > > RAX: 0000000000000000 RBX: 0000000000000005 RCX: ffffffff814153b0 > > RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88801a41f730 > > RBP: 0000000000000001 R08: ffffed1003483ee7 R09: ffffed1003483ee7 > > R10: 0000000000000001 R11: ffffed1003483ee6 R12: ffffffff86908460 > > R13: ffffffff859a01a0 R14: ffffffff812b6bc0 R15: ffff888017fb0420 > > debug_object_assert_init+0x290/0x430 linux/lib/debugobjects.c:866 > > debug_timer_assert_init linux/kernel/time/timer.c:729 [inline] > > debug_assert_init linux/kernel/time/timer.c:774 [inline] > > del_timer+0x67/0xf0 linux/kernel/time/timer.c:1196 > > realtek_cr_destructor+0x5a/0x90 linux/drivers/usb/storage/realtek_cr.c:937 > > usb_stor_release_resources linux/drivers/usb/storage/usb.c:817 [inline] > > release_everything+0xc0/0x2c0 linux/drivers/usb/storage/usb.c:879 > > usb_unbind_interface+0x19f/0x810 linux/drivers/usb/core/driver.c:423 > > __device_release_driver linux/drivers/base/dd.c:1134 [inline] > > device_release_driver_internal+0x429/0x4f0 linux/drivers/base/dd.c:1165 > > bus_remove_device+0x2d1/0x490 linux/drivers/base/bus.c:532 > > device_del+0x403/0xaa0 linux/drivers/base/core.c:2375 > > usb_disable_device+0x1d7/0x5f0 linux/drivers/usb/core/message.c:1237 > > usb_disconnect+0x25a/0x840 linux/drivers/usb/core/hub.c:2199 > > hub_port_connect linux/drivers/usb/core/hub.c:4949 [inline] > > hub_port_connect_change linux/drivers/usb/core/hub.c:5213 [inline] > > port_event linux/drivers/usb/core/hub.c:5359 [inline] > > hub_event+0x11f5/0x3610 linux/drivers/usb/core/hub.c:5441 > > process_one_work+0x8b5/0x17c0 linux/kernel/workqueue.c:2269 > > worker_thread+0x82/0xb80 linux/kernel/workqueue.c:2415 > > kthread+0x325/0x3e0 linux/kernel/kthread.c:255 > > ret_from_fork+0x24/0x30 linux/arch/x86/entry/entry_64.S:352 > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Kernel Offset: disabled > > > > Following is my analysis of this bug (Just add some comments in source code): > > https://github.com/torvalds/linux/blob/e0703556644a531e50b5dc61b9f6ea83af5f6604/drivers/usb/storage/realtek_cr.c#L887-L891 > > static int realtek_cr_autosuspend_setup(struct us_data *us) > > { > > ... > > if (retval != STATUS_SUCCESS) { > > usb_stor_dbg(us, "Read status fail\n"); > > return -EIO; // Error! > > } > > ... > > timer_setup(&chip->rts51x_suspend_timer, rts51x_suspend_timer_fn, > > 0); // rts51x_suspend_timer wasn't be initialized. When > > realtek_cr_autosuspend_setup just returns an error. > > } > > > > > > https://github.com/torvalds/linux/blob/e0703556644a531e50b5dc61b9f6ea83af5f6604/drivers/usb/storage/realtek_cr.c#L1010-L1012 > > > > #ifdef CONFIG_REALTEK_AUTOPM > > if (ss_en) > > realtek_cr_autosuspend_setup(us); // There isn't any check about > > return code. > > #endif > > > > https://github.com/torvalds/linux/blob/e0703556644a531e50b5dc61b9f6ea83af5f6604/drivers/usb/storage/realtek_cr.c#L936-L939 > > static void realtek_cr_destructor(void *extra) > > { > > ... > > if (ss_en) { > > del_timer(&chip->rts51x_suspend_timer); // Ouch! :( > > chip->timer_expires = 0; > > } > > ... > > }
