[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 41.028267][ T26] audit: type=1800 audit(1571007506.118:25): pid=7759 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 41.068138][ T26] audit: type=1800 audit(1571007506.118:26): pid=7759 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 41.118005][ T26] audit: type=1800 audit(1571007506.128:27): pid=7759 uid=0 auid=4294967295 ses=4294967295 subj=_ 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 '10.128.1.25' (ECDSA) to the list of known hosts. executing program executing program executing program executing program syzkaller login: [ 51.723883][ T7914] IPVS: ftp: loaded support on port[0] = 21 executing program executing program [ 51.847135][ T7937] [ 51.849496][ T7937] ====================================================== [ 51.856490][ T7937] WARNING: possible circular locking dependency detected [ 51.863485][ T7937] 5.4.0-rc2+ #0 Not tainted [ 51.867957][ T7937] ------------------------------------------------------ [ 51.874949][ T7937] syz-executor296/7937 is trying to acquire lock: [ 51.881332][ T7937] ffff888092bd4998 (&mm->mmap_sem#2){++++}, at: __might_fault+0xd2/0x160 [ 51.889734][ T7937] [ 51.889734][ T7937] but task is already holding lock: [ 51.897083][ T7937] ffff8880a819d100 (&rp->fetch_lock){+.+.}, at: mon_bin_fetch+0x34/0x300 [ 51.905486][ T7937] [ 51.905486][ T7937] which lock already depends on the new lock. [ 51.905486][ T7937] [ 51.915873][ T7937] [ 51.915873][ T7937] the existing dependency chain (in reverse order) is: [ 51.924890][ T7937] [ 51.924890][ T7937] -> #1 (&rp->fetch_lock){+.+.}: [ 51.932101][ T7937] lock_acquire+0x158/0x250 [ 51.937115][ T7937] __mutex_lock_common+0x14c/0x2e20 [ 51.942831][ T7937] mutex_lock_nested+0x1b/0x30 [ 51.948104][ T7937] mon_bin_vma_fault+0x6d/0x260 [ 51.953468][ T7937] __do_fault+0x144/0x3d0 [ 51.958324][ T7937] handle_mm_fault+0x42f1/0x5ff0 [ 51.963762][ T7937] __get_user_pages+0x1002/0x1610 [ 51.969298][ T7937] populate_vma_page_range+0x1fd/0x250 [ 51.975706][ T7937] __mm_populate+0x278/0x3d0 [ 51.980790][ T7937] vm_mmap_pgoff+0x1a0/0x1d0 [ 51.985873][ T7937] ksys_mmap_pgoff+0x46b/0x560 [ 51.991140][ T7937] __x64_sys_mmap+0x103/0x120 [ 51.997284][ T7937] do_syscall_64+0xf7/0x1c0 [ 52.002385][ T7937] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 52.008786][ T7937] [ 52.008786][ T7937] -> #0 (&mm->mmap_sem#2){++++}: [ 52.015879][ T7937] validate_chain+0x161e/0x7bc0 [ 52.021238][ T7937] __lock_acquire+0xc75/0x1be0 [ 52.026577][ T7937] lock_acquire+0x158/0x250 [ 52.031580][ T7937] __might_fault+0xf5/0x160 [ 52.036587][ T7937] mon_bin_fetch+0x193/0x300 [ 52.041680][ T7937] mon_bin_ioctl+0x7f6/0xc40 [ 52.046767][ T7937] do_vfs_ioctl+0x744/0x1730 [ 52.059684][ T7937] __x64_sys_ioctl+0xe3/0x120 [ 52.064909][ T7937] do_syscall_64+0xf7/0x1c0 [ 52.069926][ T7937] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 52.076489][ T7937] [ 52.076489][ T7937] other info that might help us debug this: [ 52.076489][ T7937] [ 52.086694][ T7937] Possible unsafe locking scenario: [ 52.086694][ T7937] [ 52.094128][ T7937] CPU0 CPU1 [ 52.099520][ T7937] ---- ---- [ 52.104871][ T7937] lock(&rp->fetch_lock); [ 52.109272][ T7937] lock(&mm->mmap_sem#2); [ 52.116180][ T7937] lock(&rp->fetch_lock); [ 52.123084][ T7937] lock(&mm->mmap_sem#2); [ 52.127480][ T7937] [ 52.127480][ T7937] *** DEADLOCK *** [ 52.127480][ T7937] [ 52.135704][ T7937] 1 lock held by syz-executor296/7937: [ 52.141132][ T7937] #0: ffff8880a819d100 (&rp->fetch_lock){+.+.}, at: mon_bin_fetch+0x34/0x300 [ 52.149961][ T7937] [ 52.149961][ T7937] stack backtrace: [ 52.155837][ T7937] CPU: 0 PID: 7937 Comm: syz-executor296 Not tainted 5.4.0-rc2+ #0 [ 52.163697][ T7937] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.173727][ T7937] Call Trace: [ 52.176997][ T7937] dump_stack+0x1d8/0x2f8 [ 52.181315][ T7937] print_circular_bug+0xc2d/0xe60 [ 52.186372][ T7937] ? stack_trace_save+0xb6/0x150 [ 52.191325][ T7937] ? save_trace+0x3f/0xa20 [ 52.195781][ T7937] check_noncircular+0x206/0x3a0 [ 52.200758][ T7937] validate_chain+0x161e/0x7bc0 [ 52.205592][ T7937] ? mark_lock+0x107/0x1650 [ 52.210190][ T7937] ? __kasan_check_read+0x11/0x20 [ 52.215316][ T7937] ? mark_lock+0x107/0x1650 [ 52.219916][ T7937] ? __kasan_check_read+0x11/0x20 [ 52.224935][ T7937] ? mark_lock+0x107/0x1650 [ 52.229417][ T7937] __lock_acquire+0xc75/0x1be0 [ 52.234191][ T7937] ? trace_lock_acquire+0x159/0x1d0 [ 52.239379][ T7937] lock_acquire+0x158/0x250 [ 52.243868][ T7937] ? __might_fault+0xd2/0x160 [ 52.248520][ T7937] __might_fault+0xf5/0x160 [ 52.252996][ T7937] ? __might_fault+0xd2/0x160 [ 52.257659][ T7937] mon_bin_fetch+0x193/0x300 [ 52.262236][ T7937] mon_bin_ioctl+0x7f6/0xc40 [ 52.266926][ T7937] ? mon_bin_poll+0x150/0x150 [ 52.271609][ T7937] do_vfs_ioctl+0x744/0x1730 [ 52.276177][ T7937] ? __fget+0x4b1/0x510 [ 52.280308][ T7937] ? tomoyo_file_ioctl+0x23/0x30 [ 52.285408][ T7937] ? security_file_ioctl+0xa1/0xd0 [ 52.290498][ T7937] __x64_sys_ioctl+0xe3/0x120 [ 52.295267][ T7937] do_syscall_64+0xf7/0x1c0 [ 52.299787][ T7937] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 52.305662][ T7937] RIP: 0033:0x44a859 [ 52.309541][ T7937] 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 [ 52.329150][ T7937] RSP: 002b:00007f72154ffce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 52.337712][ T7937] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 000000000044a859 [ 52.345675][ T7937] RDX: 0000000020000280 RSI: 00000000c0109207 RDI: 0000000000000003 executing program [ 52.353661][ T7937] RBP: 00000000006dbc30 R08: 00007f7215500700 R09: 0000000000000000 [ 52.361606][ T7937] R10: 00007f7215500700 R11: 0000000000000246 R12: 00000000006dbc3c [ 52.369554][ T7937] R13: 00007ffca2ee670f R14: 00007f72155009c0 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