[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 55.593196][ T26] audit: type=1800 audit(1571363736.718:25): pid=8669 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 55.631348][ T26] audit: type=1800 audit(1571363736.718:26): pid=8669 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 55.673394][ T26] audit: type=1800 audit(1571363736.728:27): pid=8669 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 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. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.28' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 65.688191][ T8824] IPVS: ftp: loaded support on port[0] = 21 [ 65.770472][ T8827] [ 65.772865][ T8827] ====================================================== [ 65.779858][ T8827] WARNING: possible circular locking dependency detected [ 65.786852][ T8827] 5.4.0-rc3-next-20191017 #0 Not tainted [ 65.792463][ T8827] ------------------------------------------------------ [ 65.799464][ T8827] syz-executor764/8827 is trying to acquire lock: [ 65.805850][ T8827] ffff8880917c3518 (&mm->mmap_sem#2){++++}, at: __might_fault+0xfb/0x1e0 [ 65.814250][ T8827] [ 65.814250][ T8827] but task is already holding lock: [ 65.821587][ T8827] ffff8880a8aa2900 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 65.829899][ T8827] [ 65.829899][ T8827] which lock already depends on the new lock. [ 65.829899][ T8827] [ 65.840290][ T8827] [ 65.840290][ T8827] the existing dependency chain (in reverse order) is: [ 65.849277][ T8827] [ 65.849277][ T8827] -> #1 (&rp->fetch_lock){+.+.}: [ 65.856373][ T8827] __mutex_lock+0x156/0x13c0 [ 65.861455][ T8827] mutex_lock_nested+0x16/0x20 [ 65.866714][ T8827] mon_bin_vma_fault+0x73/0x2d0 [ 65.872062][ T8827] __do_fault+0x111/0x540 [ 65.876886][ T8827] __handle_mm_fault+0x2d49/0x3fd0 [ 65.882499][ T8827] handle_mm_fault+0x3b2/0xa90 [ 65.887758][ T8827] __get_user_pages+0x7cf/0x1b20 [ 65.893209][ T8827] populate_vma_page_range+0x20d/0x2a0 [ 65.899159][ T8827] __mm_populate+0x204/0x380 [ 65.904248][ T8827] vm_mmap_pgoff+0x213/0x230 [ 65.909331][ T8827] ksys_mmap_pgoff+0x4aa/0x630 [ 65.914590][ T8827] __x64_sys_mmap+0xe9/0x1b0 [ 65.919675][ T8827] do_syscall_64+0xfa/0x760 [ 65.924672][ T8827] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 65.931063][ T8827] [ 65.931063][ T8827] -> #0 (&mm->mmap_sem#2){++++}: [ 65.938152][ T8827] __lock_acquire+0x2596/0x4a00 [ 65.943505][ T8827] lock_acquire+0x190/0x410 [ 65.948510][ T8827] __might_fault+0x15e/0x1e0 [ 65.953603][ T8827] _copy_to_user+0x30/0x160 [ 65.958598][ T8827] mon_bin_read+0x329/0x640 [ 65.963593][ T8827] __vfs_read+0x8a/0x110 [ 65.968334][ T8827] vfs_read+0x1f0/0x440 [ 65.972985][ T8827] ksys_read+0x14f/0x290 [ 65.977725][ T8827] __x64_sys_read+0x73/0xb0 [ 65.982721][ T8827] do_syscall_64+0xfa/0x760 [ 65.987720][ T8827] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 65.994118][ T8827] [ 65.994118][ T8827] other info that might help us debug this: [ 65.994118][ T8827] [ 66.004340][ T8827] Possible unsafe locking scenario: [ 66.004340][ T8827] [ 66.011770][ T8827] CPU0 CPU1 [ 66.017116][ T8827] ---- ---- [ 66.022453][ T8827] lock(&rp->fetch_lock); [ 66.026839][ T8827] lock(&mm->mmap_sem#2); [ 66.033750][ T8827] lock(&rp->fetch_lock); [ 66.040659][ T8827] lock(&mm->mmap_sem#2); [ 66.045043][ T8827] [ 66.045043][ T8827] *** DEADLOCK *** [ 66.045043][ T8827] [ 66.053163][ T8827] 1 lock held by syz-executor764/8827: [ 66.058599][ T8827] #0: ffff8880a8aa2900 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 66.067347][ T8827] [ 66.067347][ T8827] stack backtrace: [ 66.073223][ T8827] CPU: 0 PID: 8827 Comm: syz-executor764 Not tainted 5.4.0-rc3-next-20191017 #0 [ 66.082214][ T8827] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.092241][ T8827] Call Trace: [ 66.095513][ T8827] dump_stack+0x172/0x1f0 [ 66.099817][ T8827] print_circular_bug.isra.0.cold+0x163/0x172 [ 66.105860][ T8827] check_noncircular+0x32e/0x3e0 [ 66.110769][ T8827] ? print_circular_bug.isra.0+0x230/0x230 [ 66.116547][ T8827] ? mark_lock+0xc2/0x1220 [ 66.120959][ T8827] ? alloc_list_entry+0xc0/0xc0 [ 66.125794][ T8827] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 66.132019][ T8827] ? find_first_zero_bit+0x9a/0xc0 [ 66.137111][ T8827] __lock_acquire+0x2596/0x4a00 [ 66.142031][ T8827] ? mark_held_locks+0xf0/0xf0 [ 66.146769][ T8827] lock_acquire+0x190/0x410 [ 66.151258][ T8827] ? __might_fault+0xfb/0x1e0 [ 66.155911][ T8827] __might_fault+0x15e/0x1e0 [ 66.160471][ T8827] ? __might_fault+0xfb/0x1e0 [ 66.165123][ T8827] _copy_to_user+0x30/0x160 [ 66.169602][ T8827] mon_bin_read+0x329/0x640 [ 66.174079][ T8827] ? security_file_permission+0x8f/0x380 [ 66.179698][ T8827] __vfs_read+0x8a/0x110 [ 66.183913][ T8827] ? copy_from_buf.isra.0+0x1d0/0x1d0 [ 66.189255][ T8827] vfs_read+0x1f0/0x440 [ 66.193401][ T8827] ksys_read+0x14f/0x290 [ 66.197629][ T8827] ? kernel_write+0x130/0x130 [ 66.202278][ T8827] ? do_syscall_64+0x26/0x760 [ 66.206932][ T8827] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 66.212970][ T8827] ? do_syscall_64+0x26/0x760 [ 66.217618][ T8827] __x64_sys_read+0x73/0xb0 [ 66.222099][ T8827] do_syscall_64+0xfa/0x760 [ 66.226574][ T8827] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 66.232442][ T8827] RIP: 0033:0x44a7a9 [ 66.236312][ T8827] 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 [ 66.255885][ T8827] RSP: 002b:00007f0671627ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 66.264281][ T8827] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 000000000044a7a9 executing program executing program executing program executing program executing program executing program executing program [ 66.272379][ T8827] RDX: 0000000000000031 RSI: 0000000020000000 RDI: 0000000000000003 [ 66.280332][ T8827] RBP: 00000000006dbc30 R08: 00007f0671628700 R09: 0000000000000000 [ 66.288291][ T8827] R10: 00007f0671628700 R11: 0000000000000246 R12: 00000000006dbc3c [ 66.296248][ T8827] R13: 00007ffc2da2707f R14: 00007f06716289c0 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