====================================================== WARNING: possible circular locking dependency detected 5.2.0-rc7+ #13 Not tainted ------------------------------------------------------ syz-executor083/7953 is trying to acquire lock: 000000002d006398 (&rp->fetch_lock){+.+.}, at: mon_bin_vma_fault+0x6d/0x260 drivers/usb/mon/mon_bin.c:1237 but task is already holding lock: 00000000d7d74bbf (&mm->mmap_sem#2){++++}, at: __mm_populate+0x1a9/0x470 mm/gup.c:1588 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&mm->mmap_sem#2){++++}: __might_fault+0xf5/0x160 mm/memory.c:4496 _copy_to_user+0x2c/0xf0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:152 [inline] mon_bin_read+0x1ac/0x7b0 drivers/usb/mon/mon_bin.c:825 do_loop_readv_writev fs/read_write.c:714 [inline] do_iter_read+0x4b1/0x5b0 fs/read_write.c:935 vfs_readv fs/read_write.c:997 [inline] do_preadv+0x200/0x350 fs/read_write.c:1089 __do_sys_preadv fs/read_write.c:1139 [inline] __se_sys_preadv fs/read_write.c:1134 [inline] __x64_sys_preadv+0x9e/0xb0 fs/read_write.c:1134 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&rp->fetch_lock){+.+.}: lock_acquire+0x158/0x250 kernel/locking/lockdep.c:4303 __mutex_lock_common+0x17c/0x2fc0 kernel/locking/mutex.c:926 __mutex_lock kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1088 mon_bin_vma_fault+0x6d/0x260 drivers/usb/mon/mon_bin.c:1237 __do_fault+0x154/0x390 mm/memory.c:3127 do_cow_fault mm/memory.c:3566 [inline] do_fault mm/memory.c:3668 [inline] handle_pte_fault mm/memory.c:3897 [inline] __handle_mm_fault mm/memory.c:4021 [inline] handle_mm_fault+0x37c9/0x6130 mm/memory.c:4058 faultin_page mm/gup.c:654 [inline] __get_user_pages+0x1096/0x1710 mm/gup.c:857 populate_vma_page_range+0x1fd/0x250 mm/gup.c:1560 __mm_populate+0x2ea/0x470 mm/gup.c:1608 mm_populate include/linux/mm.h:2411 [inline] vm_mmap_pgoff+0x1f0/0x240 mm/util.c:368 ksys_mmap_pgoff+0x4ed/0x5f0 mm/mmap.c:1611 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem#2); lock(&rp->fetch_lock); lock(&mm->mmap_sem#2); lock(&rp->fetch_lock); *** DEADLOCK *** 1 lock held by syz-executor083/7953: #0: 00000000d7d74bbf (&mm->mmap_sem#2){++++}, at: __mm_populate+0x1a9/0x470 mm/gup.c:1588 stack backtrace: CPU: 0 PID: 7953 Comm: syz-executor083 Not tainted 5.2.0-rc7+ #13 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+0x1d8/0x2f8 lib/dump_stack.c:113 print_circular_bug+0xd34/0xf20 kernel/locking/lockdep.c:1564 check_prev_add kernel/locking/lockdep.c:2310 [inline] check_prevs_add kernel/locking/lockdep.c:2418 [inline] validate_chain+0x59d0/0x84f0 kernel/locking/lockdep.c:2800 __lock_acquire+0xcf7/0x1a40 kernel/locking/lockdep.c:3793 lock_acquire+0x158/0x250 kernel/locking/lockdep.c:4303 __mutex_lock_common+0x17c/0x2fc0 kernel/locking/mutex.c:926 __mutex_lock kernel/locking/mutex.c:1073 [inline] mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1088 mon_bin_vma_fault+0x6d/0x260 drivers/usb/mon/mon_bin.c:1237 __do_fault+0x154/0x390 mm/memory.c:3127 do_cow_fault mm/memory.c:3566 [inline] do_fault mm/memory.c:3668 [inline] handle_pte_fault mm/memory.c:3897 [inline] __handle_mm_fault mm/memory.c:4021 [inline] handle_mm_fault+0x37c9/0x6130 mm/memory.c:4058 faultin_page mm/gup.c:654 [inline] __get_user_pages+0x1096/0x1710 mm/gup.c:857 populate_vma_page_range+0x1fd/0x250 mm/gup.c:1560 __mm_populate+0x2ea/0x470 mm/gup.c:1608 mm_populate include/linux/mm.h:2411 [inline] vm_mmap_pgoff+0x1f0/0x240 mm/util.c:368 ksys_mmap_pgoff+0x4ed/0x5f0 mm/mmap.c:1611 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4497f9 Code: e8 ec b9 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f685ff15cd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 00000000004497f9 RDX: 0000000000000002 RSI: 0000000000400000 RDI: 0000000020a05000 RBP: 00000000006dac30 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000008012 R11: 0000000000000246 R12: 00000000006dac3c R13: 00007ffdc9b055ef R14: 00007f685ff169c0 R15: 20c49ba5e353f7cf