[ 37.503677] audit: type=1800 audit(1571278885.714:32): pid=7380 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2450 res=0 Starting mcstransd: [....] 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. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 41.911036] kauditd_printk_skb: 2 callbacks suppressed [ 41.911049] audit: type=1400 audit(1571278890.194:35): avc: denied { map } for pid=7554 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 '10.128.0.165' (ECDSA) to the list of known hosts. executing program [ 48.360333] audit: type=1400 audit(1571278896.644:36): avc: denied { map } for pid=7566 comm="syz-executor241" path="/root/syz-executor241504612" 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 [ 48.373931] IPVS: ftp: loaded support on port[0] = 21 [ 48.415201] audit: type=1400 audit(1571278896.694:37): avc: denied { map } for pid=7567 comm="syz-executor241" path="/dev/usbmon0" dev="devtmpfs" ino=1249 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 [ 48.463316] [ 48.464979] ====================================================== [ 48.471282] WARNING: possible circular locking dependency detected [ 48.477583] 4.19.79 #0 Not tainted [ 48.481100] ------------------------------------------------------ [ 48.487491] syz-executor241/7569 is trying to acquire lock: [ 48.493180] 00000000477d8c88 (&mm->mmap_sem){++++}, at: __might_fault+0xfb/0x1e0 [ 48.500800] [ 48.500800] but task is already holding lock: [ 48.506751] 000000000a7da780 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 48.514372] [ 48.514372] which lock already depends on the new lock. [ 48.514372] [ 48.522677] [ 48.522677] the existing dependency chain (in reverse order) is: [ 48.530280] [ 48.530280] -> #1 (&rp->fetch_lock){+.+.}: [ 48.536004] __mutex_lock+0xf7/0x1300 [ 48.540318] mutex_lock_nested+0x16/0x20 [ 48.544884] mon_bin_vma_fault+0x73/0x2d0 [ 48.549540] __do_fault+0x111/0x480 [ 48.553669] __handle_mm_fault+0x2d78/0x3f80 [ 48.558580] handle_mm_fault+0x1b5/0x690 [ 48.563144] __get_user_pages+0x609/0x17a0 [ 48.567882] populate_vma_page_range+0x20d/0x2a0 [ 48.573143] __mm_populate+0x204/0x380 [ 48.577532] vm_mmap_pgoff+0x213/0x230 [ 48.581934] ksys_mmap_pgoff+0x4aa/0x630 [ 48.586512] __x64_sys_mmap+0xe9/0x1b0 [ 48.590917] do_syscall_64+0xfd/0x620 [ 48.595230] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.600923] [ 48.600923] -> #0 (&mm->mmap_sem){++++}: [ 48.606457] lock_acquire+0x16f/0x3f0 [ 48.610768] __might_fault+0x15e/0x1e0 [ 48.615170] _copy_to_user+0x30/0x120 [ 48.619491] mon_bin_read+0x329/0x640 [ 48.623795] __vfs_read+0x114/0x800 [ 48.627933] vfs_read+0x194/0x3d0 [ 48.631889] ksys_read+0x14f/0x2d0 [ 48.635941] __x64_sys_read+0x73/0xb0 [ 48.640260] do_syscall_64+0xfd/0x620 [ 48.644583] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.650281] [ 48.650281] other info that might help us debug this: [ 48.650281] [ 48.658404] Possible unsafe locking scenario: [ 48.658404] [ 48.664441] CPU0 CPU1 [ 48.669095] ---- ---- [ 48.673741] lock(&rp->fetch_lock); [ 48.677435] lock(&mm->mmap_sem); [ 48.683483] lock(&rp->fetch_lock); [ 48.689695] lock(&mm->mmap_sem); [ 48.693225] [ 48.693225] *** DEADLOCK *** [ 48.693225] [ 48.699282] 1 lock held by syz-executor241/7569: [ 48.704021] #0: 000000000a7da780 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 48.712075] [ 48.712075] stack backtrace: [ 48.716559] CPU: 1 PID: 7569 Comm: syz-executor241 Not tainted 4.19.79 #0 [ 48.723468] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.733694] Call Trace: [ 48.736271] dump_stack+0x172/0x1f0 [ 48.739886] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 48.745242] __lock_acquire+0x2e19/0x49c0 [ 48.749376] ? mark_held_locks+0xb1/0x100 [ 48.753524] ? mark_held_locks+0x100/0x100 [ 48.757744] ? _raw_spin_unlock_irqrestore+0xa4/0xe0 [ 48.762837] ? __lock_is_held+0xb6/0x140 [ 48.766893] ? __lock_acquire+0x6ee/0x49c0 [ 48.771126] lock_acquire+0x16f/0x3f0 [ 48.774914] ? __might_fault+0xfb/0x1e0 [ 48.778877] __might_fault+0x15e/0x1e0 [ 48.782752] ? __might_fault+0xfb/0x1e0 [ 48.786711] _copy_to_user+0x30/0x120 [ 48.790498] mon_bin_read+0x329/0x640 [ 48.794289] __vfs_read+0x114/0x800 [ 48.797902] ? copy_from_buf.isra.0+0x1c0/0x1c0 [ 48.802572] ? vfs_copy_file_range+0xba0/0xba0 [ 48.807249] ? __inode_security_revalidate+0xda/0x120 [ 48.812433] ? avc_policy_seqno+0xd/0x70 [ 48.816478] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 48.821482] ? security_file_permission+0x89/0x230 [ 48.826407] ? rw_verify_area+0x118/0x360 [ 48.830558] vfs_read+0x194/0x3d0 [ 48.833995] ksys_read+0x14f/0x2d0 [ 48.837518] ? kernel_write+0x120/0x120 [ 48.841479] ? do_syscall_64+0x26/0x620 [ 48.845438] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.850789] ? do_syscall_64+0x26/0x620 [ 48.854759] __x64_sys_read+0x73/0xb0 [ 48.858560] do_syscall_64+0xfd/0x620 [ 48.862349] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 48.867521] RIP: 0033:0x449fc9 [ 48.870698] 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 [ 48.889593] RSP: 002b:00007fea8156ace8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 48.897298] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 0000000000449fc9 [ 48.904553] RDX: 0000000000000016 RSI: 0000000020000100 RDI: 0000000000000003 [ 48.911807] RBP: 00000000006dbc30 R08: 00007fea8156b700 R09: 0000000000000000 [ 48.919061] R10: 00007fea8156b700 R11: 0000000000000246 R12: 00000000006dbc3c [ 48.926317] R13: 00007ffd9324971f R14: 00007fea8156b9c0 R15: 000000000000002d