Extracting prog: 2m36.108054443s
Minimizing prog: 5m55.700431093s
Simplifying prog options: 6m56.017126699s
Extracting C: 34.922675161s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program crashed: possible deadlock in mdc800_device_open
single: successfully extracted reproducer
found reproducer with 2 syscalls
minimizing guilty program
testing program (duration=49.847921149s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)

program did not crash
testing program (duration=49.847921149s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program did not crash
testing program (duration=49.847921149s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, 0x0, 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program did not crash
testing program (duration=49.847921149s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=49.847921149s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
program did not crash
simplifying guilty program options
testing program (duration=49.847921149s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program crashed: possible deadlock in mdc800_device_open
extracting C reproducer
testing compiled C program (duration=49.847921149s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
program did not crash
testing program (duration=49.847921149s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program crashed: possible deadlock in mdc800_device_open
extracting C reproducer
testing compiled C program (duration=49.847921149s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
program did not crash
testing program (duration=49.847921149s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program crashed: possible deadlock in mdc800_device_open
extracting C reproducer
testing compiled C program (duration=49.847921149s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
program did not crash
testing program (duration=49.847921149s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program crashed: possible deadlock in mdc800_device_open
validation run: crashed=true
testing program (duration=49.847921149s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program crashed: possible deadlock in mdc800_device_open
validation run: crashed=true
testing program (duration=49.847921149s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_usb_connect-syz_open_dev$char_usb
detailed listing:
executing program 0:
syz_usb_connect(0x0, 0x40, &(0x7f0000000000)=ANY=[@ANYBLOB="12011001000000085f0500a800010000000109022e0001010080320904000004ff00000007050102080000070582030800010705030240000007058402400000"], 0x0)
syz_open_dev$char_usb(0xc, 0xb4, 0x0)

program crashed: possible deadlock in mdc800_device_open
validation run: crashed=true
reproducing took 21m16.745228366s
repro crashed as (corrupted=false):
raw-gadget.0 gadget.0: fail, usb_ep_enable returned -22
raw-gadget.0 gadget.0: fail, usb_ep_enable returned -22
raw-gadget.0 gadget.0: fail, usb_ep_enable returned -22
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5820 is trying to acquire lock:
ffff888028bb4218 (&mdc800->io_lock){+.+.}-{4:4}, at: mdc800_device_open+0x2e/0x470 drivers/usb/image/mdc800.c:611

but task is already holding lock:
ffffffff8f8f0988 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x30/0x1e0 drivers/usb/core/file.c:38

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (minor_rwsem#2){++++}-{4:4}:
       down_write+0x96/0x200 kernel/locking/rwsem.c:1631
       usb_register_dev+0x142/0x5e0 drivers/usb/core/file.c:134
       mdc800_usb_probe+0xf96/0x18c0 drivers/usb/image/mdc800.c:485
       usb_probe_interface+0x653/0xc60 drivers/usb/core/driver.c:396
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x254/0xae0 drivers/base/dd.c:706
       __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
       driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
       __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
       bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
       __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
       device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
       bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
       device_add+0x7d7/0xb80 drivers/base/core.c:3776
       usb_set_configuration+0x1ad8/0x2180 drivers/usb/core/message.c:2268
       usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
       usb_probe_device+0x1c3/0x3b0 drivers/usb/core/driver.c:291
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x254/0xae0 drivers/base/dd.c:706
       __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
       driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
       __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
       bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
       __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
       device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
       bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
       device_add+0x7d7/0xb80 drivers/base/core.c:3776
       usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2703
       hub_port_connect drivers/usb/core/hub.c:5575 [inline]
       hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
       port_event drivers/usb/core/hub.c:5879 [inline]
       hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5961
       process_one_work kernel/workqueue.c:3387 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (&mdc800->io_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3181 [inline]
       check_prevs_add kernel/locking/lockdep.c:3300 [inline]
       validate_chain kernel/locking/lockdep.c:3924 [inline]
       __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       mdc800_device_open+0x2e/0x470 drivers/usb/image/mdc800.c:611
       usb_open+0x156/0x1e0 drivers/usb/core/file.c:47
       chrdev_open+0x4d9/0x600 fs/char_dev.c:411
       do_dentry_open+0x816/0x1380 fs/open.c:996
       vfs_open+0x3b/0x340 fs/open.c:1101
       do_open fs/namei.c:4837 [inline]
       path_openat+0x1443/0x1d60 fs/namei.c:5000
       do_file_open+0x23e/0x4a0 fs/namei.c:5029
       do_sys_openat2+0x115/0x200 fs/open.c:1417
       do_sys_open fs/open.c:1423 [inline]
       __do_compat_sys_openat fs/open.c:1485 [inline]
       __se_compat_sys_openat fs/open.c:1483 [inline]
       __ia32_compat_sys_openat+0x131/0x160 fs/open.c:1483
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
       do_int80_emulation+0x198/0x500 arch/x86/entry/syscall_32.c:166
       asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(minor_rwsem#2);
                               lock(&mdc800->io_lock);
                               lock(minor_rwsem#2);
  lock(&mdc800->io_lock);

 *** DEADLOCK ***

locks held by syz.0.17/5820: 1, last CPU#0:
 #0: ffffffff8f8f0988 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x30/0x1e0 drivers/usb/core/file.c:38

stack backtrace:
CPU: 0 UID: 0 PID: 5820 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2059
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2191
 check_prev_add kernel/locking/lockdep.c:3181 [inline]
 check_prevs_add kernel/locking/lockdep.c:3300 [inline]
 validate_chain kernel/locking/lockdep.c:3924 [inline]
 __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
 mdc800_device_open+0x2e/0x470 drivers/usb/image/mdc800.c:611
 usb_open+0x156/0x1e0 drivers/usb/core/file.c:47
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_compat_sys_openat fs/open.c:1485 [inline]
 __se_compat_sys_openat fs/open.c:1483 [inline]
 __ia32_compat_sys_openat+0x131/0x160 fs/open.c:1483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 do_int80_emulation+0x198/0x500 arch/x86/entry/syscall_32.c:166
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf71a74eb
Code: 57 56 53 8b 44 24 14 f6 00 08 75 23 8b 44 24 18 8b 5c 24 1c 8b 4c 24 20 8b 54 24 24 8b 74 24 28 8b 7c 24 2c 8b 6c 24 30 cd 80 <5b> 5e 5f 5d c3 5b 5e 5f 5d e9 f7 a1 ff ff 66 90 66 90 66 90 90 53
RSP: 002b:00000000ffcee49c EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000ffcee560
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	57                   	push   %rdi
   1:	56                   	push   %rsi
   2:	53                   	push   %rbx
   3:	8b 44 24 14          	mov    0x14(%rsp),%eax
   7:	f6 00 08             	testb  $0x8,(%rax)
   a:	75 23                	jne    0x2f
   c:	8b 44 24 18          	mov    0x18(%rsp),%eax
  10:	8b 5c 24 1c          	mov    0x1c(%rsp),%ebx
  14:	8b 4c 24 20          	mov    0x20(%rsp),%ecx
  18:	8b 54 24 24          	mov    0x24(%rsp),%edx
  1c:	8b 74 24 28          	mov    0x28(%rsp),%esi
  20:	8b 7c 24 2c          	mov    0x2c(%rsp),%edi
  24:	8b 6c 24 30          	mov    0x30(%rsp),%ebp
  28:	cd 80                	int    $0x80
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	5e                   	pop    %rsi
  2c:	5f                   	pop    %rdi
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	5b                   	pop    %rbx
  30:	5e                   	pop    %rsi
  31:	5f                   	pop    %rdi
  32:	5d                   	pop    %rbp
  33:	e9 f7 a1 ff ff       	jmp    0xffffa22f
  38:	66 90                	xchg   %ax,%ax
  3a:	66 90                	xchg   %ax,%ax
  3c:	66 90                	xchg   %ax,%ax
  3e:	90                   	nop
  3f:	53                   	push   %rbx

final repro crashed as (corrupted=false):
raw-gadget.0 gadget.0: fail, usb_ep_enable returned -22
raw-gadget.0 gadget.0: fail, usb_ep_enable returned -22
raw-gadget.0 gadget.0: fail, usb_ep_enable returned -22
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5820 is trying to acquire lock:
ffff888028bb4218 (&mdc800->io_lock){+.+.}-{4:4}, at: mdc800_device_open+0x2e/0x470 drivers/usb/image/mdc800.c:611

but task is already holding lock:
ffffffff8f8f0988 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x30/0x1e0 drivers/usb/core/file.c:38

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (minor_rwsem#2){++++}-{4:4}:
       down_write+0x96/0x200 kernel/locking/rwsem.c:1631
       usb_register_dev+0x142/0x5e0 drivers/usb/core/file.c:134
       mdc800_usb_probe+0xf96/0x18c0 drivers/usb/image/mdc800.c:485
       usb_probe_interface+0x653/0xc60 drivers/usb/core/driver.c:396
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x254/0xae0 drivers/base/dd.c:706
       __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
       driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
       __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
       bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
       __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
       device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
       bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
       device_add+0x7d7/0xb80 drivers/base/core.c:3776
       usb_set_configuration+0x1ad8/0x2180 drivers/usb/core/message.c:2268
       usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
       usb_probe_device+0x1c3/0x3b0 drivers/usb/core/driver.c:291
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x254/0xae0 drivers/base/dd.c:706
       __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
       driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
       __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
       bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
       __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
       device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
       bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
       device_add+0x7d7/0xb80 drivers/base/core.c:3776
       usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2703
       hub_port_connect drivers/usb/core/hub.c:5575 [inline]
       hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
       port_event drivers/usb/core/hub.c:5879 [inline]
       hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5961
       process_one_work kernel/workqueue.c:3387 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (&mdc800->io_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3181 [inline]
       check_prevs_add kernel/locking/lockdep.c:3300 [inline]
       validate_chain kernel/locking/lockdep.c:3924 [inline]
       __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       mdc800_device_open+0x2e/0x470 drivers/usb/image/mdc800.c:611
       usb_open+0x156/0x1e0 drivers/usb/core/file.c:47
       chrdev_open+0x4d9/0x600 fs/char_dev.c:411
       do_dentry_open+0x816/0x1380 fs/open.c:996
       vfs_open+0x3b/0x340 fs/open.c:1101
       do_open fs/namei.c:4837 [inline]
       path_openat+0x1443/0x1d60 fs/namei.c:5000
       do_file_open+0x23e/0x4a0 fs/namei.c:5029
       do_sys_openat2+0x115/0x200 fs/open.c:1417
       do_sys_open fs/open.c:1423 [inline]
       __do_compat_sys_openat fs/open.c:1485 [inline]
       __se_compat_sys_openat fs/open.c:1483 [inline]
       __ia32_compat_sys_openat+0x131/0x160 fs/open.c:1483
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
       do_int80_emulation+0x198/0x500 arch/x86/entry/syscall_32.c:166
       asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(minor_rwsem#2);
                               lock(&mdc800->io_lock);
                               lock(minor_rwsem#2);
  lock(&mdc800->io_lock);

 *** DEADLOCK ***

locks held by syz.0.17/5820: 1, last CPU#0:
 #0: ffffffff8f8f0988 (minor_rwsem#2){++++}-{4:4}, at: usb_open+0x30/0x1e0 drivers/usb/core/file.c:38

stack backtrace:
CPU: 0 UID: 0 PID: 5820 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2059
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2191
 check_prev_add kernel/locking/lockdep.c:3181 [inline]
 check_prevs_add kernel/locking/lockdep.c:3300 [inline]
 validate_chain kernel/locking/lockdep.c:3924 [inline]
 __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
 mdc800_device_open+0x2e/0x470 drivers/usb/image/mdc800.c:611
 usb_open+0x156/0x1e0 drivers/usb/core/file.c:47
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_compat_sys_openat fs/open.c:1485 [inline]
 __se_compat_sys_openat fs/open.c:1483 [inline]
 __ia32_compat_sys_openat+0x131/0x160 fs/open.c:1483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 do_int80_emulation+0x198/0x500 arch/x86/entry/syscall_32.c:166
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf71a74eb
Code: 57 56 53 8b 44 24 14 f6 00 08 75 23 8b 44 24 18 8b 5c 24 1c 8b 4c 24 20 8b 54 24 24 8b 74 24 28 8b 7c 24 2c 8b 6c 24 30 cd 80 <5b> 5e 5f 5d c3 5b 5e 5f 5d e9 f7 a1 ff ff 66 90 66 90 66 90 90 53
RSP: 002b:00000000ffcee49c EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000ffcee560
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	57                   	push   %rdi
   1:	56                   	push   %rsi
   2:	53                   	push   %rbx
   3:	8b 44 24 14          	mov    0x14(%rsp),%eax
   7:	f6 00 08             	testb  $0x8,(%rax)
   a:	75 23                	jne    0x2f
   c:	8b 44 24 18          	mov    0x18(%rsp),%eax
  10:	8b 5c 24 1c          	mov    0x1c(%rsp),%ebx
  14:	8b 4c 24 20          	mov    0x20(%rsp),%ecx
  18:	8b 54 24 24          	mov    0x24(%rsp),%edx
  1c:	8b 74 24 28          	mov    0x28(%rsp),%esi
  20:	8b 7c 24 2c          	mov    0x2c(%rsp),%edi
  24:	8b 6c 24 30          	mov    0x30(%rsp),%ebp
  28:	cd 80                	int    $0x80
* 2a:	5b                   	pop    %rbx <-- trapping instruction
  2b:	5e                   	pop    %rsi
  2c:	5f                   	pop    %rdi
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	5b                   	pop    %rbx
  30:	5e                   	pop    %rsi
  31:	5f                   	pop    %rdi
  32:	5d                   	pop    %rbp
  33:	e9 f7 a1 ff ff       	jmp    0xffffa22f
  38:	66 90                	xchg   %ax,%ax
  3a:	66 90                	xchg   %ax,%ax
  3c:	66 90                	xchg   %ax,%ax
  3e:	90                   	nop
  3f:	53                   	push   %rbx