[ 40.459939][ T26] audit: type=1800 audit(1571150683.780:27): pid=7676 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0
[ 40.493063][ T26] audit: type=1800 audit(1571150683.780:28): pid=7676 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2417 res=0
[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[ 41.295320][ T26] audit: type=1800 audit(1571150684.680:29): pid=7676 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0
[ 41.314594][ T26] audit: type=1800 audit(1571150684.680:30): pid=7676 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0
Debian GNU/Linux 7 syzkaller ttyS0
Warning: Permanently added '10.128.0.101' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [ 51.242911][ T7831]
[ 51.245392][ T7831] ======================================================
[ 51.252411][ T7831] WARNING: possible circular locking dependency detected
[ 51.259428][ T7831] 5.4.0-rc3+ #0 Not tainted
[ 51.263899][ T7831] ------------------------------------------------------
[ 51.271050][ T7831] syz-executor752/7831 is trying to acquire lock:
[ 51.277432][ T7831] ffff8880a959c100 (&rp->fetch_lock){+.+.}, at: mon_bin_vma_fault+0x6d/0x260
[ 51.286168][ T7831]
[ 51.286168][ T7831] but task is already holding lock:
[ 51.293506][ T7831] ffff888091a515d8 (&mm->mmap_sem#2){++++}, at: __mm_populate+0x156/0x3d0
[ 51.301993][ T7831]
[ 51.301993][ T7831] which lock already depends on the new lock.
[ 51.301993][ T7831]
[ 51.312368][ T7831]
[ 51.312368][ T7831] the existing dependency chain (in reverse order) is:
[ 51.321351][ T7831]
[ 51.321351][ T7831] -> #1 (&mm->mmap_sem#2){++++}:
[ 51.328434][ T7831] lock_acquire+0x158/0x250
[ 51.333704][ T7831] __might_fault+0xf5/0x160
[ 51.338715][ T7831] _copy_to_user+0x2c/0x150
[ 51.343715][ T7831] mon_bin_read+0x1ac/0x7b0
[ 51.348714][ T7831] __vfs_read+0xb8/0x730
[ 51.353541][ T7831] vfs_read+0x1dd/0x420
[ 51.358188][ T7831] ksys_read+0x117/0x220
[ 51.362938][ T7831] __x64_sys_read+0x7b/0x90
[ 51.368028][ T7831] do_syscall_64+0xf7/0x1c0
[ 51.373020][ T7831] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 51.379402][ T7831]
[ 51.379402][ T7831] -> #0 (&rp->fetch_lock){+.+.}:
[ 51.386486][ T7831] validate_chain+0x161e/0x7bc0
[ 51.391826][ T7831] __lock_acquire+0xc75/0x1be0
[ 51.397093][ T7831] lock_acquire+0x158/0x250
[ 51.402100][ T7831] __mutex_lock_common+0x14c/0x2e20
[ 51.407790][ T7831] mutex_lock_nested+0x1b/0x30
[ 51.414010][ T7831] mon_bin_vma_fault+0x6d/0x260
[ 51.419353][ T7831] __do_fault+0x144/0x3d0
[ 51.424183][ T7831] handle_mm_fault+0x42f1/0x5ff0
[ 51.429782][ T7831] __get_user_pages+0x1002/0x1610
[ 51.435303][ T7831] populate_vma_page_range+0x1fd/0x250
[ 51.441251][ T7831] __mm_populate+0x278/0x3d0
[ 51.446331][ T7831] vm_mmap_pgoff+0x1a0/0x1d0
[ 51.451411][ T7831] ksys_mmap_pgoff+0x46b/0x560
[ 51.456663][ T7831] __x64_sys_mmap+0x103/0x120
[ 51.461831][ T7831] do_syscall_64+0xf7/0x1c0
[ 51.466828][ T7831] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 51.473221][ T7831]
[ 51.473221][ T7831] other info that might help us debug this:
[ 51.473221][ T7831]
[ 51.483421][ T7831] Possible unsafe locking scenario:
[ 51.483421][ T7831]
[ 51.490838][ T7831] CPU0 CPU1
[ 51.496174][ T7831] ---- ----
[ 51.501508][ T7831] lock(&mm->mmap_sem#2);
[ 51.505892][ T7831] lock(&rp->fetch_lock);
[ 51.512790][ T7831] lock(&mm->mmap_sem#2);
[ 51.519700][ T7831] lock(&rp->fetch_lock);
[ 51.524083][ T7831]
[ 51.524083][ T7831] *** DEADLOCK ***
[ 51.524083][ T7831]
[ 51.532199][ T7831] 1 lock held by syz-executor752/7831:
[ 51.537618][ T7831] #0: ffff888091a515d8 (&mm->mmap_sem#2){++++}, at: __mm_populate+0x156/0x3d0
[ 51.546526][ T7831]
[ 51.546526][ T7831] stack backtrace:
[ 51.552393][ T7831] CPU: 1 PID: 7831 Comm: syz-executor752 Not tainted 5.4.0-rc3+ #0
[ 51.560258][ T7831] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 51.570282][ T7831] Call Trace:
[ 51.573543][ T7831] dump_stack+0x1d8/0x2f8
[ 51.577852][ T7831] print_circular_bug+0xc2d/0xe60
[ 51.582853][ T7831] ? stack_trace_save+0xb6/0x150
[ 51.587776][ T7831] ? save_trace+0x3f/0xa20
[ 51.592173][ T7831] check_noncircular+0x206/0x3a0
[ 51.597093][ T7831] validate_chain+0x161e/0x7bc0
[ 51.601926][ T7831] ? __kasan_check_read+0x11/0x20
[ 51.606935][ T7831] ? mark_lock+0x107/0x1650
[ 51.611427][ T7831] ? register_lock_class+0x99/0xea0
[ 51.616689][ T7831] ? lockdep_hardirqs_on+0x3c5/0x7d0
[ 51.621996][ T7831] ? _raw_spin_unlock_irqrestore+0x77/0xe0
[ 51.627783][ T7831] __lock_acquire+0xc75/0x1be0
[ 51.632547][ T7831] ? kasan_slab_alloc+0xf/0x20
[ 51.637281][ T7831] ? kmem_cache_alloc+0x1f5/0x2e0
[ 51.642278][ T7831] ? ptlock_alloc+0x20/0x70
[ 51.646753][ T7831] ? pte_alloc_one+0x6e/0x180
[ 51.651397][ T7831] ? __do_fault+0xdd/0x3d0
[ 51.655784][ T7831] ? handle_mm_fault+0x42f1/0x5ff0
[ 51.660866][ T7831] ? trace_lock_acquire+0x159/0x1d0
[ 51.666033][ T7831] lock_acquire+0x158/0x250
[ 51.670598][ T7831] ? mon_bin_vma_fault+0x6d/0x260
[ 51.675591][ T7831] __mutex_lock_common+0x14c/0x2e20
[ 51.680762][ T7831] ? mon_bin_vma_fault+0x6d/0x260
[ 51.685762][ T7831] ? mon_bin_vma_fault+0x6d/0x260
[ 51.690761][ T7831] ? lockdep_init_map+0x2a/0x680
[ 51.695668][ T7831] mutex_lock_nested+0x1b/0x30
[ 51.700401][ T7831] mon_bin_vma_fault+0x6d/0x260
[ 51.705224][ T7831] __do_fault+0x144/0x3d0
[ 51.709610][ T7831] handle_mm_fault+0x42f1/0x5ff0
[ 51.714518][ T7831] __get_user_pages+0x1002/0x1610
[ 51.719545][ T7831] populate_vma_page_range+0x1fd/0x250
[ 51.725065][ T7831] __mm_populate+0x278/0x3d0
[ 51.729637][ T7831] vm_mmap_pgoff+0x1a0/0x1d0
[ 51.734283][ T7831] ksys_mmap_pgoff+0x46b/0x560
[ 51.739016][ T7831] __x64_sys_mmap+0x103/0x120
[ 51.743674][ T7831] do_syscall_64+0xf7/0x1c0
[ 51.748160][ T7831] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 51.754021][ T7831] RIP: 0033:0x449789
[ 51.758071][ T7831] 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
[ 51.779503][ T7831] RSP: 002b:00007f6267a6ccd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
[ 51.787898][ T7831] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000449789
[ 51.795844][ T7831] RDX: 0000000002000001 RSI: 0000000002000000 RDI: 0000000020ffd000
[ 51.803800][ T7831] RBP: 00000000006dac30 R08: 0000000000000005 R09: 0000000000000000
[ 51.811751][ T7831] R10: 03eb6b06d1207692 R11: 0000000000000246 R12: 00000000006dac3c
[ 51.819715][ T7831] R13: 00007fffb93562ff R14: 00007f6267a6d9c0 R15: 20c49ba5e353f7cf