[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 38.932455] audit: type=1800 audit(1555647720.647:33): pid=7368 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0 [?25l[?1c7[ ok 8[?25h[?0c[ 38.957342] audit: type=1800 audit(1555647720.677:34): pid=7368 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 . [ 39.286746] audit: type=1400 audit(1555647720.997:35): avc: denied { map } for pid=7542 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.19' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 45.841125] audit: type=1400 audit(1555647727.557:36): avc: denied { map } for pid=7555 comm="syz-executor633" path="/root/syz-executor633751310" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program [ 46.011209] audit: type=1400 audit(1555647727.727:37): avc: denied { map } for pid=7565 comm="syz-executor633" path="/dev/usbmon0" dev="devtmpfs" ino=16478 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:usbmon_device_t:s0 tclass=chr_file permissive=1 [ 46.011365] [ 46.038444] ====================================================== [ 46.044735] WARNING: possible circular locking dependency detected [ 46.051035] 4.19.35 #3 Not tainted [ 46.054558] ------------------------------------------------------ [ 46.060857] syz-executor633/7567 is trying to acquire lock: [ 46.066668] 0000000008143b74 (&rp->fetch_lock){+.+.}, at: mon_bin_vma_fault+0x73/0x2d0 [ 46.074716] [ 46.074716] but task is already holding lock: [ 46.080668] 000000008e89a112 (&mm->mmap_sem){++++}, at: __mm_populate+0x270/0x380 [ 46.088293] [ 46.088293] which lock already depends on the new lock. [ 46.088293] [ 46.096588] [ 46.096588] the existing dependency chain (in reverse order) is: [ 46.104199] [ 46.104199] -> #1 (&mm->mmap_sem){++++}: [ 46.109732] __might_fault+0x15e/0x1e0 [ 46.114123] _copy_to_user+0x30/0x120 [ 46.118423] mon_bin_get_event+0x117/0x450 [ 46.123158] mon_bin_ioctl+0xacf/0xc80 [ 46.127666] do_vfs_ioctl+0xd6e/0x1390 [ 46.132082] ksys_ioctl+0xab/0xd0 [ 46.136035] __x64_sys_ioctl+0x73/0xb0 [ 46.140426] do_syscall_64+0x103/0x610 [ 46.144833] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.150523] [ 46.150523] -> #0 (&rp->fetch_lock){+.+.}: [ 46.156225] lock_acquire+0x16f/0x3f0 [ 46.160526] __mutex_lock+0xf7/0x1300 [ 46.164824] mutex_lock_nested+0x16/0x20 [ 46.169387] mon_bin_vma_fault+0x73/0x2d0 [ 46.174046] __do_fault+0x116/0x480 [ 46.178192] __handle_mm_fault+0xf72/0x3f80 [ 46.183020] handle_mm_fault+0x43f/0xb30 [ 46.187588] __get_user_pages+0x609/0x1770 [ 46.192324] populate_vma_page_range+0x20d/0x2a0 [ 46.197592] __mm_populate+0x204/0x380 [ 46.201994] vm_mmap_pgoff+0x213/0x230 [ 46.206387] ksys_mmap_pgoff+0x4aa/0x630 [ 46.210961] __x64_sys_mmap+0xe9/0x1b0 [ 46.215349] do_syscall_64+0x103/0x610 [ 46.219738] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.225421] [ 46.225421] other info that might help us debug this: [ 46.225421] [ 46.233540] Possible unsafe locking scenario: [ 46.233540] [ 46.239573] CPU0 CPU1 [ 46.244214] ---- ---- [ 46.248854] lock(&mm->mmap_sem); [ 46.252371] lock(&rp->fetch_lock); [ 46.258584] lock(&mm->mmap_sem); [ 46.264617] lock(&rp->fetch_lock); [ 46.268322] [ 46.268322] *** DEADLOCK *** [ 46.268322] [ 46.274366] 1 lock held by syz-executor633/7567: [ 46.279096] #0: 000000008e89a112 (&mm->mmap_sem){++++}, at: __mm_populate+0x270/0x380 [ 46.287142] [ 46.287142] stack backtrace: [ 46.291619] CPU: 0 PID: 7567 Comm: syz-executor633 Not tainted 4.19.35 #3 [ 46.298525] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.307869] Call Trace: [ 46.310444] dump_stack+0x172/0x1f0 [ 46.314054] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 46.319408] __lock_acquire+0x2e6d/0x48f0 [ 46.323537] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 46.328619] ? depot_save_stack+0x1de/0x460 [ 46.332930] ? _raw_spin_unlock_irqrestore+0x6b/0xe0 [ 46.338015] ? mark_held_locks+0x100/0x100 [ 46.342250] ? save_stack+0x45/0xd0 [ 46.345860] ? kasan_kmalloc+0xce/0xf0 [ 46.349728] ? kasan_slab_alloc+0xf/0x20 [ 46.353770] ? kmem_cache_alloc+0x12e/0x700 [ 46.358074] ? __lock_is_held+0xb6/0x140 [ 46.362120] ? __mm_populate+0x204/0x380 [ 46.366167] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.370474] lock_acquire+0x16f/0x3f0 [ 46.374426] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.378727] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.383034] __mutex_lock+0xf7/0x1300 [ 46.386814] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.391116] ? __lock_is_held+0xb6/0x140 [ 46.395156] ? mon_bin_vma_fault+0x73/0x2d0 [ 46.399458] ? mutex_trylock+0x1e0/0x1e0 [ 46.403496] ? __lock_is_held+0xb6/0x140 [ 46.407540] ? rcu_read_lock_sched_held+0x110/0x130 [ 46.412538] ? kmem_cache_alloc+0x32d/0x700 [ 46.416843] mutex_lock_nested+0x16/0x20 [ 46.420885] ? mutex_lock_nested+0x16/0x20 [ 46.425120] mon_bin_vma_fault+0x73/0x2d0 [ 46.429249] __do_fault+0x116/0x480 [ 46.432857] ? mem_cgroup_try_charge_delay+0x6c/0xa0 [ 46.437941] __handle_mm_fault+0xf72/0x3f80 [ 46.442257] ? vmf_insert_mixed_mkwrite+0x90/0x90 [ 46.447083] ? find_held_lock+0x35/0x130 [ 46.451122] ? handle_mm_fault+0x322/0xb30 [ 46.455338] ? kasan_check_read+0x11/0x20 [ 46.459467] handle_mm_fault+0x43f/0xb30 [ 46.463523] __get_user_pages+0x609/0x1770 [ 46.467742] ? follow_page_mask+0x19c0/0x19c0 [ 46.472220] ? memset+0x32/0x40 [ 46.475481] populate_vma_page_range+0x20d/0x2a0 [ 46.480221] __mm_populate+0x204/0x380 [ 46.484114] ? populate_vma_page_range+0x2a0/0x2a0 [ 46.489048] vm_mmap_pgoff+0x213/0x230 [ 46.492922] ? vma_is_stack_for_current+0xd0/0xd0 [ 46.497748] ? iterate_fd+0x360/0x360 [ 46.501532] ksys_mmap_pgoff+0x4aa/0x630 [ 46.505577] ? find_mergeable_anon_vma+0x2e0/0x2e0 [ 46.510494] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.515241] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.519977] ? do_syscall_64+0x26/0x610 [ 46.523932] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.529277] __x64_sys_mmap+0xe9/0x1b0 [ 46.533171] do_syscall_64+0x103/0x610 [ 46.537053] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 46.542220] RIP: 0033:0x44a6b9 [ 46.545397] Code: e8 8c b5 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 2b cc fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 46.564279] RSP: 002b:00007f825e9bccd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 [ 46.571981] RAX: ffffffffffffffda RBX: 00000000006dbc58 RCX: 000000000044a6b9 [ 46.579232] RDX: 0000000000000002 RSI: 0000000000400000 RDI: 0000000020a19000 [ 46.586483] RBP: 00000000006dbc50 R08: 0000000000000005 R09: 0000000000000000 [ 46.593732] R10: 0000000000008012 R11: 0000000000000246 R12: 00000000006dbc5c [ 46.600979] R13: 00007ffc5e8ff56f R14: 00007f825e9bd9c0 R15: 20c49ba5e353f7cf executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program