[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.229785] audit: type=1800 audit(1555546115.034:33): pid=7337 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 [ 38.250790] audit: type=1800 audit(1555546115.034:34): pid=7337 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 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 43.141042] audit: type=1400 audit(1555546119.944:35): avc: denied { map } for pid=7511 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 '10.128.10.42' (ECDSA) to the list of known hosts. executing program [ 49.639106] audit: type=1400 audit(1555546126.444:36): avc: denied { map } for pid=7523 comm="syz-executor660" path="/root/syz-executor660125221" 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 [ 49.654397] IPVS: ftp: loaded support on port[0] = 21 [ 49.694362] audit: type=1400 audit(1555546126.494:37): avc: denied { map } for pid=7524 comm="syz-executor660" path="/dev/usbmon0" dev="devtmpfs" ino=16336 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 [ 49.709686] [ 49.721626] ====================================================== [ 49.727970] WARNING: possible circular locking dependency detected [ 49.734308] 4.19.35 #3 Not tainted [ 49.737831] ------------------------------------------------------ [ 49.744137] syz-executor660/7525 is trying to acquire lock: [ 49.749833] 0000000024b13cf6 (&mm->mmap_sem){++++}, at: __might_fault+0xfb/0x1e0 [ 49.757363] [ 49.757363] but task is already holding lock: [ 49.763316] 00000000fbe10d7f (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 49.771718] [ 49.771718] which lock already depends on the new lock. [ 49.771718] [ 49.780018] [ 49.780018] the existing dependency chain (in reverse order) is: [ 49.787635] [ 49.787635] -> #1 (&rp->fetch_lock){+.+.}: [ 49.793345] __mutex_lock+0xf7/0x1300 [ 49.797658] mutex_lock_nested+0x16/0x20 [ 49.802228] mon_bin_vma_fault+0x73/0x2d0 [ 49.806882] __do_fault+0x116/0x480 [ 49.811011] __handle_mm_fault+0xf72/0x3f80 [ 49.815833] handle_mm_fault+0x43f/0xb30 [ 49.820394] __get_user_pages+0x609/0x1770 [ 49.825128] populate_vma_page_range+0x20d/0x2a0 [ 49.830387] __mm_populate+0x204/0x380 [ 49.834777] vm_mmap_pgoff+0x213/0x230 [ 49.839169] ksys_mmap_pgoff+0x4aa/0x630 [ 49.843819] __x64_sys_mmap+0xe9/0x1b0 [ 49.848296] do_syscall_64+0x103/0x610 [ 49.852696] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.858493] [ 49.858493] -> #0 (&mm->mmap_sem){++++}: [ 49.864026] lock_acquire+0x16f/0x3f0 [ 49.868330] __might_fault+0x15e/0x1e0 [ 49.872718] _copy_to_user+0x30/0x120 [ 49.877034] mon_bin_read+0x329/0x640 [ 49.881347] __vfs_read+0x116/0x800 [ 49.885489] vfs_read+0x194/0x3d0 [ 49.889447] ksys_read+0xea/0x1f0 [ 49.893405] __x64_sys_read+0x73/0xb0 [ 49.897730] do_syscall_64+0x103/0x610 [ 49.902123] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 49.907809] [ 49.907809] other info that might help us debug this: [ 49.907809] [ 49.915947] Possible unsafe locking scenario: [ 49.915947] [ 49.921985] CPU0 CPU1 [ 49.926627] ---- ---- [ 49.931273] lock(&rp->fetch_lock); [ 49.934970] lock(&mm->mmap_sem); [ 49.941008] lock(&rp->fetch_lock); [ 49.947222] lock(&mm->mmap_sem); [ 49.950744] [ 49.950744] *** DEADLOCK *** [ 49.950744] [ 49.956788] 1 lock held by syz-executor660/7525: [ 49.961521] #0: 00000000fbe10d7f (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 49.969574] [ 49.969574] stack backtrace: [ 49.974056] CPU: 0 PID: 7525 Comm: syz-executor660 Not tainted 4.19.35 #3 [ 49.980965] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.990308] Call Trace: [ 49.992889] dump_stack+0x172/0x1f0 [ 49.996508] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 50.001876] __lock_acquire+0x2e6d/0x48f0 [ 50.006016] ? mark_held_locks+0xb1/0x100 [ 50.010154] ? mark_held_locks+0x100/0x100 [ 50.014387] ? _raw_spin_unlock_irqrestore+0xa4/0xe0 [ 50.019485] lock_acquire+0x16f/0x3f0 [ 50.023286] ? __might_fault+0xfb/0x1e0 [ 50.027247] __might_fault+0x15e/0x1e0 [ 50.031127] ? __might_fault+0xfb/0x1e0 [ 50.035092] _copy_to_user+0x30/0x120 [ 50.038879] mon_bin_read+0x329/0x640 [ 50.042670] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 50.048196] __vfs_read+0x116/0x800 [ 50.051807] ? copy_from_buf.isra.0+0x1c0/0x1c0 [ 50.056460] ? vfs_copy_file_range+0xba0/0xba0 [ 50.061025] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 50.066550] ? __inode_security_revalidate+0xda/0x120 [ 50.071722] ? avc_policy_seqno+0xd/0x70 [ 50.075770] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 50.080774] ? security_file_permission+0x1ce/0x230 [ 50.085775] ? security_file_permission+0x8f/0x230 [ 50.090689] ? rw_verify_area+0x118/0x360 [ 50.094820] vfs_read+0x194/0x3d0 [ 50.098280] ksys_read+0xea/0x1f0 [ 50.101715] ? kernel_write+0x120/0x120 [ 50.105681] ? do_syscall_64+0x26/0x610 [ 50.109640] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.114998] ? do_syscall_64+0x26/0x610 [ 50.118966] __x64_sys_read+0x73/0xb0 [ 50.122754] do_syscall_64+0x103/0x610 [ 50.126627] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.131801] RIP: 0033:0x449f09 [ 50.134977] 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 0b d3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 50.153860] RSP: 002b:00007f8e3cd82ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 50.161553] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000449f09 [ 50.168804] RDX: 000000000000002f RSI: 0000000000000000 RDI: 0000000000000003 [ 50.176071] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 50.183332] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 50.190583] R13: 00007fffcaddc37f R14: 00007f8e3cd839c0 R15: 000000000000002d