Am Dienstag, den 30.07.2019, 16:12 +0200 schrieb Andrey Konovalov: > On Tue, Jul 30, 2019 at 4:10 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Mon, 29 Jul 2019, syzbot wrote: > > > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: 6a3599ce usb-fuzzer: main usb gadget fuzzer driver > > > git tree: https://github.com/google/kasan.git usb-fuzzer > > > console output: https://syzkaller.appspot.com/x/log.txt?x=12386cb4600000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=700ca426ab83faae > > > dashboard link: https://syzkaller.appspot.com/bug?extid=a7a6b9c609b9457c62c6 > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > > > > Unfortunately, I don't have any reproducer for this crash yet. > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > Reported-by: syzbot+a7a6b9c609b9457c62c6@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > ------------[ cut here ]------------ > > > usb 2-1: BOGUS urb xfer, pipe 2 != type 2 > > > WARNING: CPU: 0 PID: 3730 at drivers/usb/core/urb.c:477 > > > usb_submit_urb+0x1188/0x13b0 drivers/usb/core/urb.c:477 > > > Kernel panic - not syncing: panic_on_warn set ... > > > CPU: 0 PID: 3730 Comm: syz-executor.1 Not tainted 5.2.0-rc6+ #15 > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > > Google 01/01/2011 > > > Call Trace: > > > __dump_stack lib/dump_stack.c:77 [inline] > > > dump_stack+0xca/0x13e lib/dump_stack.c:113 > > > panic+0x292/0x6c9 kernel/panic.c:219 > > > __warn.cold+0x20/0x4b kernel/panic.c:576 > > > report_bug+0x262/0x2a0 lib/bug.c:186 > > > fixup_bug arch/x86/kernel/traps.c:179 [inline] > > > fixup_bug arch/x86/kernel/traps.c:174 [inline] > > > do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:272 > > > do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:291 > > > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986 > > > RIP: 0010:usb_submit_urb+0x1188/0x13b0 drivers/usb/core/urb.c:477 > > > Code: 4d 85 ed 74 2c e8 f8 d3 f4 fd 4c 89 f7 e8 a0 51 1c ff 41 89 d8 44 89 > > > e1 4c 89 ea 48 89 c6 48 c7 c7 00 0e f7 85 e8 83 98 ca fd <0f> 0b e9 20 f4 > > > ff ff e8 cc d3 f4 fd 4c 89 f2 48 b8 00 00 00 00 00 > > > RSP: 0018:ffff8881d4f479d0 EFLAGS: 00010282 > > > RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000 > > > RDX: 0000000000005dfa RSI: ffffffff8127ef3d RDI: ffffed103a9e8f2c > > > RBP: 0000000000000000 R08: ffff8881af663000 R09: 0000000000000000 > > > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 > > > R13: ffff8881d462ed38 R14: ffff8881d18f9a20 R15: ffff8881d80e1c00 > > > usb_start_wait_urb+0x108/0x2b0 drivers/usb/core/message.c:57 > > > usb_internal_control_msg drivers/usb/core/message.c:101 [inline] > > > usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:152 > > > usbhid_set_raw_report drivers/hid/usbhid/hid-core.c:917 [inline] > > > usbhid_raw_request+0x21f/0x640 drivers/hid/usbhid/hid-core.c:1265 > > > hid_hw_raw_request include/linux/hid.h:1079 [inline] > > > hidraw_send_report+0x296/0x500 drivers/hid/hidraw.c:151 > > > hidraw_ioctl+0x5b4/0xaf0 drivers/hid/hidraw.c:421 > > > vfs_ioctl fs/ioctl.c:46 [inline] > > > file_ioctl fs/ioctl.c:509 [inline] > > > do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:696 > > > ksys_ioctl+0x9b/0xc0 fs/ioctl.c:713 > > > __do_sys_ioctl fs/ioctl.c:720 [inline] > > > __se_sys_ioctl fs/ioctl.c:718 [inline] > > > __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:718 > > > do_syscall_64+0xb7/0x560 arch/x86/entry/common.c:301 > > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > This is very strange. It looks like the kernel is complaining that 2 > > != 2. > > > > A more likely explanation is a race in the usbhid driver. If > > usbhid_set_raw_report() gets called _after_ usbhid has been unbound > > from the device and while the endpoint is being destroyed, we could get > > something like this. > > > > Perhaps one of Oliver's patches will also fix this. > > Since there's no reproducer this is quite likely some kind of race. We > can close this bug once Oliver's patches are applied, and if it gets > triggered again syzbot will rereport it. AFAICT my patch right now introduces another race. This will require a fresh look. Regards Oliver
