On Mon, 16 Sep 2019, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: f0df5c1b 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=11512cd1600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5c6633fa4ed00be5 > dashboard link: https://syzkaller.appspot.com/bug?extid=19cf612d23f66bc19f22 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16f92c6e600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b9b85e600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+19cf612d23f66bc19f22@xxxxxxxxxxxxxxxxxxxxxxxxx > > ====================================================== > WARNING: possible circular locking dependency detected > 5.3.0-rc7+ #0 Not tainted > ------------------------------------------------------ > syz-executor071/1724 is trying to acquire lock: > 00000000f749c934 (rio500_mutex){+.+.}, at: open_rio+0x16/0xe0 > drivers/usb/misc/rio500.c:65 > > but task is already holding lock: > 000000009c24ba51 (minor_rwsem){++++}, at: usb_open+0x23/0x270 > drivers/usb/core/file.c:39 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #1 (minor_rwsem){++++}: > down_write+0x92/0x150 kernel/locking/rwsem.c:1500 > usb_register_dev drivers/usb/core/file.c:187 [inline] > usb_register_dev+0x131/0x670 drivers/usb/core/file.c:156 > probe_rio.cold+0x53/0x237 drivers/usb/misc/rio500.c:474 > usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 > really_probe+0x281/0x6d0 drivers/base/dd.c:548 > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721 > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 > bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:454 > __device_attach+0x217/0x360 drivers/base/dd.c:894 > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > device_add+0xae6/0x16f0 drivers/base/core.c:2165 > usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 > generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 > usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 > really_probe+0x281/0x6d0 drivers/base/dd.c:548 > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721 > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 > bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:454 > __device_attach+0x217/0x360 drivers/base/dd.c:894 > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > device_add+0xae6/0x16f0 drivers/base/core.c:2165 > usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 > hub_port_connect drivers/usb/core/hub.c:5098 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > port_event drivers/usb/core/hub.c:5359 [inline] > hub_event+0x1b5c/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 (rio500_mutex){+.+.}: > 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 > open_rio+0x16/0xe0 drivers/usb/misc/rio500.c:65 > 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: > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(minor_rwsem); > lock(rio500_mutex); > lock(minor_rwsem); > lock(rio500_mutex); > > *** DEADLOCK *** > > 1 lock held by syz-executor071/1724: > #0: 000000009c24ba51 (minor_rwsem){++++}, at: usb_open+0x23/0x270 > drivers/usb/core/file.c:39 > > stack backtrace: > CPU: 0 PID: 1724 Comm: syz-executor071 Not tainted 5.3.0-rc7+ #0 > 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 > open_rio+0x16/0xe0 drivers/usb/misc/rio500.c:65 > 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: 0033:0x401130 > Code: 01 f0 ff ff 0f 83 00 0b 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f > 44 00 00 83 3d 5d 0c 2d 00 00 75 14 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff > ff 0f 83 d4 0a 00 00 c3 48 83 ec 08 e8 3a 00 00 00 > RSP: 002b:00007ffca0216788 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 > RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000401130 > RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007ffca02167a0 > RBP: 00000000006cb018 R08: 0000000000000000 R09: 000000000000000f > R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000402090 > R13: 0000000000402120 R14: 0000000000000000 R15: 00 > > > --- > 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. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches This is undoubted the same as the previous bug report. It should be fixed by commit 9472aff16ca0 in Greg KH's usb-next branch, but the fix is not yet in Linus's tree. #syz dup: possible deadlock in open_rio Alan Stern
