bisecting fixing commit since 3dbdb38e286903ec220aaf1fb29a8d94297da246 building syzkaller on 8f5a7b8cde529e0a19a53f79bdf9c6cad306827b testing commit 3dbdb38e286903ec220aaf1fb29a8d94297da246 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 8481f9b2f2a7ab11d955c97afbc70c98b55326b531dbb64e72a19810026b3ae0 all runs: crashed: WARNING in dlfb_submit_urb/usb_submit_urb testing current HEAD ba31f97d43be41ca99ab72a6131d7c226306865f testing commit ba31f97d43be41ca99ab72a6131d7c226306865f compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: da690622c5e433a0eae04444028916f460653a7b53b9461eabaeecde98763992 all runs: crashed: WARNING in dlfb_submit_urb/usb_submit_urb revisions tested: 2, total time: 26m58.825567458s (build: 19m37.016249827s, test: 6m53.230762315s) the crash still happens on HEAD commit msg: Merge tag 'for-linus-5.14-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip crash: WARNING in dlfb_submit_urb/usb_submit_urb ------------[ cut here ]------------ usb 3-1: BOGUS urb xfer, pipe 3 != type 1 WARNING: CPU: 0 PID: 8640 at drivers/usb/core/urb.c:502 usb_submit_urb+0xb07/0x1680 drivers/usb/core/urb.c:502 Modules linked in: CPU: 0 PID: 8640 Comm: kworker/0:4 Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event RIP: 0010:usb_submit_urb+0xb07/0x1680 drivers/usb/core/urb.c:502 Code: 4c 24 18 89 4c 24 08 44 89 04 24 e8 13 81 21 ff 44 8b 04 24 4c 89 e2 48 c7 c7 60 68 5f 89 8b 4c 24 08 48 89 c6 e8 38 27 3d 03 <0f> 0b 4c 8b 4c 24 18 e9 c0 fa ff ff 48 8d 7b 1c 48 ba 00 00 00 00 RSP: 0018:ffffc900021e6d70 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888018441000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff891f5d00 RDI: fffff5200043cda0 RBP: ffff88801c7ee800 R08: 0000000000000001 R09: ffff8880b9e2ff47 R10: ffffed10173c5fe8 R11: 3a312d3320627375 R12: ffff8880386cb480 R13: 000000000000000b R14: 0000000000000003 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc924a6720 CR3: 0000000039467000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dlfb_submit_urb+0x6c/0x140 drivers/video/fbdev/udlfb.c:1969 dlfb_set_video_mode+0x1fe2/0x2940 drivers/video/fbdev/udlfb.c:315 dlfb_ops_set_par+0x275/0x890 drivers/video/fbdev/udlfb.c:1110 dlfb_usb_probe.cold+0x1091/0x1d05 drivers/video/fbdev/udlfb.c:1732 usb_probe_interface+0x274/0x6a0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_set_configuration+0xc1d/0x1710 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x74/0xa0 drivers/usb/core/generic.c:238 usb_probe_device+0x95/0x240 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:517 [inline] really_probe+0x1b9/0xb70 drivers/base/dd.c:595 __driver_probe_device+0x2a6/0x460 drivers/base/dd.c:747 driver_probe_device+0x44/0x110 drivers/base/dd.c:777 __device_attach_driver+0x185/0x250 drivers/base/dd.c:894 bus_for_each_drv+0x11e/0x1a0 drivers/base/bus.c:427 __device_attach+0x1db/0x410 drivers/base/dd.c:965 bus_probe_device+0x19d/0x250 drivers/base/bus.c:487 device_add+0xa2f/0x1e00 drivers/base/core.c:3354 usb_new_device.cold+0x5cf/0xedf drivers/usb/core/hub.c:2563 hub_port_connect drivers/usb/core/hub.c:5348 [inline] hub_port_connect_change drivers/usb/core/hub.c:5488 [inline] port_event drivers/usb/core/hub.c:5634 [inline] hub_event+0x10a3/0x36c0 drivers/usb/core/hub.c:5716 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0x1040 kernel/workqueue.c:2422 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 4c 24 18 rex.WR and $0x18,%al 3: 89 4c 24 08 mov %ecx,0x8(%rsp) 7: 44 89 04 24 mov %r8d,(%rsp) b: e8 13 81 21 ff callq 0xff218123 10: 44 8b 04 24 mov (%rsp),%r8d 14: 4c 89 e2 mov %r12,%rdx 17: 48 c7 c7 60 68 5f 89 mov $0xffffffff895f6860,%rdi 1e: 8b 4c 24 08 mov 0x8(%rsp),%ecx 22: 48 89 c6 mov %rax,%rsi 25: e8 38 27 3d 03 callq 0x33d2762 2a: 0f 0b ud2 <-- trapping instruction 2c: 4c 8b 4c 24 18 mov 0x18(%rsp),%r9 31: e9 c0 fa ff ff jmpq 0xfffffaf6 36: 48 8d 7b 1c lea 0x1c(%rbx),%rdi 3a: 48 rex.W 3b: ba 00 00 00 00 mov $0x0,%edx