======================================================
WARNING: possible circular locking dependency detected
5.4.0-rc1+ #0 Not tainted
------------------------------------------------------
syz-executor371/2539 is trying to acquire lock:
ffff88808cde7218 (&mm->mmap_sem#2){++++}, at: __might_fault+0xfb/0x1e0 mm/memory.c:4449

but task is already holding lock:
ffff8880a963c1c0 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 drivers/usb/mon/mon_bin.c:813

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&rp->fetch_lock){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:956 [inline]
       __mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
       mon_bin_vma_fault+0x73/0x2d0 drivers/usb/mon/mon_bin.c:1237
       __do_fault+0x111/0x540 mm/memory.c:3092
       do_read_fault mm/memory.c:3489 [inline]
       do_fault mm/memory.c:3618 [inline]
       handle_pte_fault mm/memory.c:3849 [inline]
       __handle_mm_fault+0x2dd0/0x4040 mm/memory.c:3973
       handle_mm_fault+0x3b7/0xaa0 mm/memory.c:4010
       faultin_page mm/gup.c:640 [inline]
       __get_user_pages+0x7d4/0x1b30 mm/gup.c:845
       populate_vma_page_range+0x20d/0x2a0 mm/gup.c:1223
       __mm_populate+0x204/0x380 mm/gup.c:1271
       mm_populate include/linux/mm.h:2362 [inline]
       vm_mmap_pgoff+0x213/0x230 mm/util.c:501
       ksys_mmap_pgoff+0x4aa/0x630 mm/mmap.c:1629
       __do_sys_mmap_pgoff mm/mmap.c:1640 [inline]
       __se_sys_mmap_pgoff mm/mmap.c:1636 [inline]
       __ia32_sys_mmap_pgoff+0xdd/0x1a0 mm/mmap.c:1636
       do_syscall_32_irqs_on arch/x86/entry/common.c:333 [inline]
       do_fast_syscall_32+0x27b/0xdb3 arch/x86/entry/common.c:404
       entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

-> #0 (&mm->mmap_sem#2){++++}:
       check_prev_add kernel/locking/lockdep.c:2476 [inline]
       check_prevs_add kernel/locking/lockdep.c:2581 [inline]
       validate_chain kernel/locking/lockdep.c:2971 [inline]
       __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3955
       lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
       __might_fault mm/memory.c:4450 [inline]
       __might_fault+0x15e/0x1e0 mm/memory.c:4435
       _copy_to_user+0x30/0x160 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:152 [inline]
       mon_bin_read+0x329/0x640 drivers/usb/mon/mon_bin.c:825
       __vfs_read+0x8a/0x110 fs/read_write.c:425
       vfs_read+0x1f0/0x440 fs/read_write.c:461
       ksys_read+0x14f/0x290 fs/read_write.c:587
       __do_sys_read fs/read_write.c:597 [inline]
       __se_sys_read fs/read_write.c:595 [inline]
       __ia32_sys_read+0x71/0xb0 fs/read_write.c:595
       do_syscall_32_irqs_on arch/x86/entry/common.c:333 [inline]
       do_fast_syscall_32+0x27b/0xdb3 arch/x86/entry/common.c:404
       entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rp->fetch_lock);
                               lock(&mm->mmap_sem#2);
                               lock(&rp->fetch_lock);
  lock(&mm->mmap_sem#2);

 *** DEADLOCK ***

1 lock held by syz-executor371/2539:
 #0: ffff8880a963c1c0 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 drivers/usb/mon/mon_bin.c:813

stack backtrace:
CPU: 0 PID: 2539 Comm: syz-executor371 Not tainted 5.4.0-rc1+ #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+0x172/0x1f0 lib/dump_stack.c:113
 print_circular_bug.isra.0.cold+0x163/0x172 kernel/locking/lockdep.c:1685
 check_noncircular+0x32e/0x3e0 kernel/locking/lockdep.c:1809
 check_prev_add kernel/locking/lockdep.c:2476 [inline]
 check_prevs_add kernel/locking/lockdep.c:2581 [inline]
 validate_chain kernel/locking/lockdep.c:2971 [inline]
 __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3955
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
 __might_fault mm/memory.c:4450 [inline]
 __might_fault+0x15e/0x1e0 mm/memory.c:4435
 _copy_to_user+0x30/0x160 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:152 [inline]
 mon_bin_read+0x329/0x640 drivers/usb/mon/mon_bin.c:825
 __vfs_read+0x8a/0x110 fs/read_write.c:425
 vfs_read+0x1f0/0x440 fs/read_write.c:461
 ksys_read+0x14f/0x290 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __ia32_sys_read+0x71/0xb0 fs/read_write.c:595
 do_syscall_32_irqs_on arch/x86/entry/common.c:333 [inline]
 do_fast_syscall_32+0x27b/0xdb3 arch/x86/entry/common.c:404
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f8fa29
Code: b8 80 96 98 00 eb cc 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f7f6a12c EFLAGS: 00000286 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000250 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000