[ 40.348396][ T26] audit: type=1800 audit(1571006048.688:27): pid=7683 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [ 40.381859][ T26] audit: type=1800 audit(1571006048.758:28): pid=7683 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[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 40.974660][ T26] audit: type=1800 audit(1571006049.358:29): pid=7683 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 40.994189][ T26] audit: type=1800 audit(1571006049.358:30): pid=7683 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 '10.128.0.41' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 56.847200][ T7837] IPVS: ftp: loaded support on port[0] = 21 [ 56.934192][ T7844] [ 56.936544][ T7844] ====================================================== [ 56.943628][ T7844] WARNING: possible circular locking dependency detected [ 56.950619][ T7844] 5.4.0-rc2+ #0 Not tainted [ 56.955087][ T7844] ------------------------------------------------------ [ 56.962077][ T7844] syz-executor493/7844 is trying to acquire lock: [ 56.968462][ T7844] ffff88809a730198 (&mm->mmap_sem#2){++++}, at: __might_fault+0xd2/0x160 [ 56.976877][ T7844] [ 56.976877][ T7844] but task is already holding lock: [ 56.984245][ T7844] ffff88809ec0d900 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x5c/0x7b0 [ 56.992546][ T7844] [ 56.992546][ T7844] which lock already depends on the new lock. [ 56.992546][ T7844] [ 57.002919][ T7844] [ 57.002919][ T7844] the existing dependency chain (in reverse order) is: [ 57.011904][ T7844] [ 57.011904][ T7844] -> #1 (&rp->fetch_lock){+.+.}: [ 57.019263][ T7844] lock_acquire+0x158/0x250 [ 57.024431][ T7844] __mutex_lock_common+0x14c/0x2e20 [ 57.030128][ T7844] mutex_lock_nested+0x1b/0x30 [ 57.035392][ T7844] mon_bin_vma_fault+0x6d/0x260 [ 57.041743][ T7844] __do_fault+0x144/0x3d0 [ 57.046615][ T7844] handle_mm_fault+0x42f1/0x5ff0 [ 57.052045][ T7844] __get_user_pages+0x1002/0x1610 [ 57.057563][ T7844] populate_vma_page_range+0x1fd/0x250 [ 57.063512][ T7844] __mm_populate+0x278/0x3d0 [ 57.068605][ T7844] vm_mmap_pgoff+0x1a0/0x1d0 [ 57.073686][ T7844] ksys_mmap_pgoff+0x46b/0x560 [ 57.078941][ T7844] __x64_sys_mmap+0x103/0x120 [ 57.084109][ T7844] do_syscall_64+0xf7/0x1c0 [ 57.089105][ T7844] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.095496][ T7844] [ 57.095496][ T7844] -> #0 (&mm->mmap_sem#2){++++}: [ 57.102857][ T7844] validate_chain+0x161e/0x7bc0 [ 57.108212][ T7844] __lock_acquire+0xc75/0x1be0 [ 57.113465][ T7844] lock_acquire+0x158/0x250 [ 57.118467][ T7844] __might_fault+0xf5/0x160 [ 57.123461][ T7844] _copy_to_user+0x2c/0x150 [ 57.128454][ T7844] mon_bin_read+0x1ac/0x7b0 [ 57.133446][ T7844] __vfs_read+0xb8/0x730 [ 57.138175][ T7844] vfs_read+0x1dd/0x420 [ 57.143783][ T7844] ksys_read+0x117/0x220 [ 57.148520][ T7844] __x64_sys_read+0x7b/0x90 [ 57.153788][ T7844] do_syscall_64+0xf7/0x1c0 [ 57.158809][ T7844] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.165197][ T7844] [ 57.165197][ T7844] other info that might help us debug this: [ 57.165197][ T7844] [ 57.175398][ T7844] Possible unsafe locking scenario: [ 57.175398][ T7844] [ 57.183524][ T7844] CPU0 CPU1 [ 57.188861][ T7844] ---- ---- [ 57.194195][ T7844] lock(&rp->fetch_lock); [ 57.198577][ T7844] lock(&mm->mmap_sem#2); [ 57.205477][ T7844] lock(&rp->fetch_lock); [ 57.212383][ T7844] lock(&mm->mmap_sem#2); [ 57.216766][ T7844] [ 57.216766][ T7844] *** DEADLOCK *** [ 57.216766][ T7844] [ 57.224887][ T7844] 1 lock held by syz-executor493/7844: [ 57.230317][ T7844] #0: ffff88809ec0d900 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x5c/0x7b0 [ 57.239051][ T7844] [ 57.239051][ T7844] stack backtrace: [ 57.244998][ T7844] CPU: 1 PID: 7844 Comm: syz-executor493 Not tainted 5.4.0-rc2+ #0 [ 57.252857][ T7844] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.262966][ T7844] Call Trace: [ 57.267018][ T7844] dump_stack+0x1d8/0x2f8 [ 57.271332][ T7844] print_circular_bug+0xc2d/0xe60 [ 57.276327][ T7844] ? stack_trace_save+0xb6/0x150 [ 57.281232][ T7844] ? save_trace+0x3f/0xa20 [ 57.285627][ T7844] check_noncircular+0x206/0x3a0 [ 57.290546][ T7844] validate_chain+0x161e/0x7bc0 [ 57.295372][ T7844] ? __kasan_check_read+0x11/0x20 [ 57.300381][ T7844] ? mark_lock+0x107/0x1650 [ 57.304902][ T7844] ? __lock_acquire+0xc75/0x1be0 [ 57.310242][ T7844] __lock_acquire+0xc75/0x1be0 [ 57.314981][ T7844] ? trace_lock_acquire+0x159/0x1d0 [ 57.320147][ T7844] lock_acquire+0x158/0x250 [ 57.324881][ T7844] ? __might_fault+0xd2/0x160 [ 57.329528][ T7844] __might_fault+0xf5/0x160 [ 57.334006][ T7844] ? __might_fault+0xd2/0x160 [ 57.338649][ T7844] _copy_to_user+0x2c/0x150 [ 57.343130][ T7844] mon_bin_read+0x1ac/0x7b0 [ 57.348125][ T7844] ? mon_bin_exit+0x40/0x40 [ 57.352598][ T7844] __vfs_read+0xb8/0x730 [ 57.356823][ T7844] ? security_file_permission+0x23c/0x350 [ 57.362598][ T7844] ? rw_verify_area+0x1c2/0x360 [ 57.367414][ T7844] vfs_read+0x1dd/0x420 [ 57.371549][ T7844] ksys_read+0x117/0x220 [ 57.375767][ T7844] __x64_sys_read+0x7b/0x90 [ 57.380237][ T7844] do_syscall_64+0xf7/0x1c0 [ 57.384720][ T7844] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.390580][ T7844] RIP: 0033:0x44a779 [ 57.394446][ T7844] Code: e8 ec b6 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 cc fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 57.414026][ T7844] RSP: 002b:00007fc34c2fdce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 57.422403][ T7844] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 000000000044a779 executing program [ 57.430352][ T7844] RDX: 0000000000000016 RSI: 0000000020000100 RDI: 0000000000000003 [ 57.438305][ T7844] RBP: 00000000006dbc30 R08: 00007fc34c2fe700 R09: 0000000000000000 [ 57.446252][ T7844] R10: 00007fc34c2fe700 R11: 0000000000000246 R12: 00000000006dbc3c [ 57.454197][ T7844] R13: 00007ffc75d2f6ef R14: 00007fc34c2fe9c0 R15: 0000000000000001 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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