On Thu, Aug 1, 2019 at 5:28 PM syzbot <syzbot+ca52394faa436d8131df@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 7f7867ff 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=17ab6aec600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=792eb47789f57810 > dashboard link: https://syzkaller.appspot.com/bug?extid=ca52394faa436d8131df > 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+ca52394faa436d8131df@xxxxxxxxxxxxxxxxxxxxxxxxx > > ====================================================== > WARNING: possible circular locking dependency detected > 5.3.0-rc2+ #23 Not tainted > ------------------------------------------------------ > syz-executor.0/10062 is trying to acquire lock: > 00000000527cb8c7 (iowarrior_open_disc_lock){+.+.}, at: > iowarrior_open+0x8a/0x2a0 drivers/usb/misc/iowarrior.c:600 > > but task is already holding lock: > 0000000061445bc7 (iowarrior_mutex){+.+.}, at: iowarrior_open+0x23/0x2a0 > drivers/usb/misc/iowarrior.c:589 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #2 (iowarrior_mutex){+.+.}: > __mutex_lock_common kernel/locking/mutex.c:930 [inline] > __mutex_lock+0x158/0x1360 kernel/locking/mutex.c:1077 > iowarrior_open+0x23/0x2a0 drivers/usb/misc/iowarrior.c:589 > usb_open+0x1df/0x270 drivers/usb/core/file.c:48 > chrdev_open+0x219/0x5c0 fs/char_dev.c:414 > do_dentry_open+0x494/0x1120 fs/open.c:797 > do_last fs/namei.c:3416 [inline] > path_openat+0x1430/0x3f50 fs/namei.c:3533 > do_filp_open+0x1a1/0x280 fs/namei.c:3563 > do_sys_open+0x3c0/0x580 fs/open.c:1089 > do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > -> #1 (minor_rwsem#2){++++}: > down_write+0x92/0x150 kernel/locking/rwsem.c:1500 > usb_deregister_dev drivers/usb/core/file.c:238 [inline] > usb_deregister_dev+0x61/0x270 drivers/usb/core/file.c:230 > iowarrior_disconnect+0xa8/0x2c0 drivers/usb/misc/iowarrior.c:873 > usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423 > __device_release_driver drivers/base/dd.c:1120 [inline] > device_release_driver_internal+0x404/0x4c0 drivers/base/dd.c:1151 > bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556 > device_del+0x420/0xb10 drivers/base/core.c:2288 > usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237 > usb_disconnect+0x284/0x8d0 drivers/usb/core/hub.c:2199 > hub_port_connect drivers/usb/core/hub.c:4949 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > port_event drivers/usb/core/hub.c:5359 [inline] > hub_event+0x1454/0x3640 drivers/usb/core/hub.c:5441 > process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > kthread+0x318/0x420 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > -> #0 (iowarrior_open_disc_lock){+.+.}: > check_prev_add kernel/locking/lockdep.c:2405 [inline] > check_prevs_add kernel/locking/lockdep.c:2507 [inline] > validate_chain kernel/locking/lockdep.c:2897 [inline] > __lock_acquire+0x1f7c/0x3b50 kernel/locking/lockdep.c:3880 > lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412 > __mutex_lock_common kernel/locking/mutex.c:930 [inline] > __mutex_lock+0x158/0x1360 kernel/locking/mutex.c:1077 > iowarrior_open+0x8a/0x2a0 drivers/usb/misc/iowarrior.c:600 > usb_open+0x1df/0x270 drivers/usb/core/file.c:48 > chrdev_open+0x219/0x5c0 fs/char_dev.c:414 > do_dentry_open+0x494/0x1120 fs/open.c:797 > do_last fs/namei.c:3416 [inline] > path_openat+0x1430/0x3f50 fs/namei.c:3533 > do_filp_open+0x1a1/0x280 fs/namei.c:3563 > do_sys_open+0x3c0/0x580 fs/open.c:1089 > do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > other info that might help us debug this: > > Chain exists of: > iowarrior_open_disc_lock --> minor_rwsem#2 --> iowarrior_mutex > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(iowarrior_mutex); > lock(minor_rwsem#2); > lock(iowarrior_mutex); > lock(iowarrior_open_disc_lock); > > *** DEADLOCK *** > > 2 locks held by syz-executor.0/10062: > #0: 000000000fd8903d (minor_rwsem#2){++++}, at: usb_open+0x23/0x270 > drivers/usb/core/file.c:39 > #1: 0000000061445bc7 (iowarrior_mutex){+.+.}, at: > iowarrior_open+0x23/0x2a0 drivers/usb/misc/iowarrior.c:589 > > stack backtrace: > CPU: 0 PID: 10062 Comm: syz-executor.0 Not tainted 5.3.0-rc2+ #23 > 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 > check_noncircular+0x345/0x3e0 kernel/locking/lockdep.c:1741 > check_prev_add kernel/locking/lockdep.c:2405 [inline] > check_prevs_add kernel/locking/lockdep.c:2507 [inline] > validate_chain kernel/locking/lockdep.c:2897 [inline] > __lock_acquire+0x1f7c/0x3b50 kernel/locking/lockdep.c:3880 > lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412 > __mutex_lock_common kernel/locking/mutex.c:930 [inline] > __mutex_lock+0x158/0x1360 kernel/locking/mutex.c:1077 > iowarrior_open+0x8a/0x2a0 drivers/usb/misc/iowarrior.c:600 > usb_open+0x1df/0x270 drivers/usb/core/file.c:48 > chrdev_open+0x219/0x5c0 fs/char_dev.c:414 > do_dentry_open+0x494/0x1120 fs/open.c:797 > do_last fs/namei.c:3416 [inline] > path_openat+0x1430/0x3f50 fs/namei.c:3533 > do_filp_open+0x1a1/0x280 fs/namei.c:3563 > do_sys_open+0x3c0/0x580 fs/open.c:1089 > do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x413711 > Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 > 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 > 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 > RSP: 002b:00007fbd98b927a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 > RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000413711 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fbd98b92850 > RBP: 000000000075bf20 R08: 000000000000000f R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000293 R12: 00007fbd98b936d4 > R13: 00000000004c8bee R14: 00000000004dfa68 R15: 00000000ffffffff #syz dup: possible deadlock in usb_deregister_dev > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
