[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 65.977381][ T26] kauditd_printk_skb: 7 callbacks suppressed [ 65.977393][ T26] audit: type=1800 audit(1571443837.152:39): pid=9297 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=2432 res=0 [ 66.005951][ T26] audit: type=1800 audit(1571443837.152:40): pid=9297 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=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 69.235571][ T26] audit: type=1400 audit(1571443840.412:41): avc: denied { map } for pid=9476 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 Warning: Permanently added '10.128.0.4' (ECDSA) to the list of known hosts. executing program [ 75.725378][ T26] audit: type=1400 audit(1571443846.902:42): avc: denied { map } for pid=9488 comm="syz-executor818" path="/root/syz-executor818705931" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 75.761163][ T9489] IPVS: ftp: loaded support on port[0] = 21 [ 75.792276][ T26] audit: type=1400 audit(1571443846.962:43): avc: denied { map } for pid=9489 comm="syz-executor818" path="/dev/usbmon0" dev="devtmpfs" ino=17363 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 [ 75.851698][ T9491] [ 75.854071][ T9491] ====================================================== [ 75.861066][ T9491] WARNING: possible circular locking dependency detected [ 75.868061][ T9491] 5.4.0-rc3+ #0 Not tainted [ 75.872538][ T9491] ------------------------------------------------------ [ 75.879533][ T9491] syz-executor818/9491 is trying to acquire lock: [ 75.885920][ T9491] ffff88809fd021d8 (&mm->mmap_sem#2){++++}, at: __might_fault+0xfb/0x1e0 [ 75.894323][ T9491] [ 75.894323][ T9491] but task is already holding lock: [ 75.901663][ T9491] ffff8880979b7100 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 75.909985][ T9491] [ 75.909985][ T9491] which lock already depends on the new lock. [ 75.909985][ T9491] [ 75.920363][ T9491] [ 75.920363][ T9491] the existing dependency chain (in reverse order) is: [ 75.929354][ T9491] [ 75.929354][ T9491] -> #1 (&rp->fetch_lock){+.+.}: [ 75.936496][ T9491] __mutex_lock+0x156/0x13c0 [ 75.941588][ T9491] mutex_lock_nested+0x16/0x20 [ 75.946848][ T9491] mon_bin_vma_fault+0x73/0x2d0 [ 75.952216][ T9491] __do_fault+0x111/0x540 [ 75.957045][ T9491] __handle_mm_fault+0x2dd0/0x4040 [ 75.962656][ T9491] handle_mm_fault+0x3b7/0xaa0 [ 75.967915][ T9491] __get_user_pages+0x7d4/0x1b30 [ 75.973349][ T9491] populate_vma_page_range+0x20d/0x2a0 [ 75.979325][ T9491] __mm_populate+0x204/0x380 [ 75.984414][ T9491] vm_mmap_pgoff+0x213/0x230 [ 75.989502][ T9491] ksys_mmap_pgoff+0x4aa/0x630 [ 75.994767][ T9491] __x64_sys_mmap+0xe9/0x1b0 [ 75.999857][ T9491] do_syscall_64+0xfa/0x760 [ 76.004861][ T9491] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 76.011420][ T9491] [ 76.011420][ T9491] -> #0 (&mm->mmap_sem#2){++++}: [ 76.018516][ T9491] __lock_acquire+0x2596/0x4a00 [ 76.023866][ T9491] lock_acquire+0x190/0x410 [ 76.028868][ T9491] __might_fault+0x15e/0x1e0 [ 76.033956][ T9491] _copy_to_user+0x30/0x160 [ 76.038957][ T9491] mon_bin_read+0x329/0x640 [ 76.043959][ T9491] __vfs_read+0x8a/0x110 [ 76.048700][ T9491] vfs_read+0x1f0/0x440 [ 76.053472][ T9491] ksys_read+0x14f/0x290 [ 76.058227][ T9491] __x64_sys_read+0x73/0xb0 [ 76.063253][ T9491] do_syscall_64+0xfa/0x760 [ 76.068277][ T9491] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 76.074662][ T9491] [ 76.074662][ T9491] other info that might help us debug this: [ 76.074662][ T9491] [ 76.084867][ T9491] Possible unsafe locking scenario: [ 76.084867][ T9491] [ 76.092294][ T9491] CPU0 CPU1 [ 76.097651][ T9491] ---- ---- [ 76.102991][ T9491] lock(&rp->fetch_lock); [ 76.107395][ T9491] lock(&mm->mmap_sem#2); [ 76.114326][ T9491] lock(&rp->fetch_lock); [ 76.121233][ T9491] lock(&mm->mmap_sem#2); [ 76.125623][ T9491] [ 76.125623][ T9491] *** DEADLOCK *** [ 76.125623][ T9491] [ 76.133749][ T9491] 1 lock held by syz-executor818/9491: [ 76.139177][ T9491] #0: ffff8880979b7100 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 76.147922][ T9491] [ 76.147922][ T9491] stack backtrace: [ 76.153806][ T9491] CPU: 1 PID: 9491 Comm: syz-executor818 Not tainted 5.4.0-rc3+ #0 [ 76.161671][ T9491] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 76.171700][ T9491] Call Trace: [ 76.174974][ T9491] dump_stack+0x172/0x1f0 [ 76.179288][ T9491] print_circular_bug.isra.0.cold+0x163/0x172 [ 76.185347][ T9491] check_noncircular+0x32e/0x3e0 [ 76.190264][ T9491] ? print_circular_bug.isra.0+0x230/0x230 [ 76.196050][ T9491] ? mark_lock+0xc2/0x1220 [ 76.200459][ T9491] ? alloc_list_entry+0xc0/0xc0 [ 76.205292][ T9491] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 76.211512][ T9491] ? find_first_zero_bit+0x9a/0xc0 [ 76.216605][ T9491] __lock_acquire+0x2596/0x4a00 [ 76.221440][ T9491] ? mark_held_locks+0xf0/0xf0 [ 76.226185][ T9491] lock_acquire+0x190/0x410 [ 76.230683][ T9491] ? __might_fault+0xfb/0x1e0 [ 76.235350][ T9491] __might_fault+0x15e/0x1e0 [ 76.239930][ T9491] ? __might_fault+0xfb/0x1e0 [ 76.244593][ T9491] _copy_to_user+0x30/0x160 [ 76.249165][ T9491] mon_bin_read+0x329/0x640 [ 76.253666][ T9491] ? security_file_permission+0x8f/0x380 [ 76.259279][ T9491] __vfs_read+0x8a/0x110 [ 76.263500][ T9491] ? copy_from_buf.isra.0+0x1c0/0x1c0 [ 76.268874][ T9491] vfs_read+0x1f0/0x440 [ 76.273009][ T9491] ksys_read+0x14f/0x290 [ 76.277230][ T9491] ? kernel_write+0x130/0x130 [ 76.281909][ T9491] ? do_syscall_64+0x26/0x760 [ 76.286568][ T9491] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 76.292612][ T9491] ? do_syscall_64+0x26/0x760 [ 76.297267][ T9491] __x64_sys_read+0x73/0xb0 [ 76.301751][ T9491] do_syscall_64+0xfa/0x760 [ 76.306236][ T9491] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 76.312105][ T9491] RIP: 0033:0x449fc9 [ 76.315983][ T9491] Code: e8 4c bc 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 cb d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 76.335564][ T9491] RSP: 002b:00007fc41ae00ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 76.343954][ T9491] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 0000000000449fc9 [ 76.351907][ T9491] RDX: