[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 64.691420][ T26] kauditd_printk_skb: 7 callbacks suppressed [ 64.691434][ T26] audit: type=1400 audit(1571485398.369:41): avc: denied { map } for pid=9446 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 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.158' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 71.085684][ T26] audit: type=1400 audit(1571485404.759:42): avc: denied { map } for pid=9459 comm="syz-executor762" path="/root/syz-executor762691982" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 71.123685][ T9460] IPVS: ftp: loaded support on port[0] = 21 [ 71.154675][ T26] audit: type=1400 audit(1571485404.829:43): avc: denied { map } for pid=9460 comm="syz-executor762" path="/dev/usbmon0" dev="devtmpfs" ino=18555 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 [ 71.203054][ T9462] [ 71.205406][ T9462] ====================================================== [ 71.212399][ T9462] WARNING: possible circular locking dependency detected [ 71.219393][ T9462] 5.4.0-rc3+ #0 Not tainted [ 71.223874][ T9462] ------------------------------------------------------ [ 71.230871][ T9462] syz-executor762/9462 is trying to acquire lock: [ 71.237258][ T9462] ffff8880a88455d8 (&mm->mmap_sem#2){++++}, at: __might_fault+0xfb/0x1e0 [ 71.245666][ T9462] [ 71.245666][ T9462] but task is already holding lock: [ 71.253011][ T9462] ffff8880a1a72500 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 71.262015][ T9462] [ 71.262015][ T9462] which lock already depends on the new lock. [ 71.262015][ T9462] [ 71.273086][ T9462] [ 71.273086][ T9462] the existing dependency chain (in reverse order) is: [ 71.282075][ T9462] [ 71.282075][ T9462] -> #1 (&rp->fetch_lock){+.+.}: [ 71.289176][ T9462] __mutex_lock+0x156/0x13c0 [ 71.294264][ T9462] mutex_lock_nested+0x16/0x20 [ 71.299529][ T9462] mon_bin_vma_fault+0x73/0x2d0 [ 71.304879][ T9462] __do_fault+0x111/0x540 [ 71.309707][ T9462] __handle_mm_fault+0x2dd0/0x4040 [ 71.315314][ T9462] handle_mm_fault+0x3b7/0xaa0 [ 71.320834][ T9462] __get_user_pages+0x7d4/0x1b30 [ 71.326269][ T9462] populate_vma_page_range+0x20d/0x2a0 [ 71.332266][ T9462] __mm_populate+0x204/0x380 [ 71.337354][ T9462] vm_mmap_pgoff+0x213/0x230 [ 71.342439][ T9462] ksys_mmap_pgoff+0x4aa/0x630 [ 71.347701][ T9462] __x64_sys_mmap+0xe9/0x1b0 [ 71.352790][ T9462] do_syscall_64+0xfa/0x760 [ 71.357789][ T9462] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.364170][ T9462] [ 71.364170][ T9462] -> #0 (&mm->mmap_sem#2){++++}: [ 71.371263][ T9462] __lock_acquire+0x2596/0x4a00 [ 71.376612][ T9462] lock_acquire+0x190/0x410 [ 71.381626][ T9462] __might_fault+0x15e/0x1e0 [ 71.386711][ T9462] _copy_to_user+0x30/0x160 [ 71.391709][ T9462] mon_bin_read+0x329/0x640 [ 71.396709][ T9462] __vfs_read+0x8a/0x110 [ 71.401448][ T9462] vfs_read+0x1f0/0x440 [ 71.406102][ T9462] ksys_read+0x14f/0x290 [ 71.410840][ T9462] __x64_sys_read+0x73/0xb0 [ 71.415840][ T9462] do_syscall_64+0xfa/0x760 [ 71.421621][ T9462] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.428003][ T9462] [ 71.428003][ T9462] other info that might help us debug this: [ 71.428003][ T9462] [ 71.438300][ T9462] Possible unsafe locking scenario: [ 71.438300][ T9462] [ 71.445735][ T9462] CPU0 CPU1 [ 71.451087][ T9462] ---- ---- [ 71.456427][ T9462] lock(&rp->fetch_lock); [ 71.460991][ T9462] lock(&mm->mmap_sem#2); [ 71.467899][ T9462] lock(&rp->fetch_lock); [ 71.474804][ T9462] lock(&mm->mmap_sem#2); [ 71.479200][ T9462] [ 71.479200][ T9462] *** DEADLOCK *** [ 71.479200][ T9462] [ 71.487325][ T9462] 1 lock held by syz-executor762/9462: [ 71.492753][ T9462] #0: ffff8880a1a72500 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 71.501585][ T9462] [ 71.501585][ T9462] stack backtrace: [ 71.507456][ T9462] CPU: 1 PID: 9462 Comm: syz-executor762 Not tainted 5.4.0-rc3+ #0 [ 71.515319][ T9462] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.525347][ T9462] Call Trace: [ 71.528624][ T9462] dump_stack+0x172/0x1f0 [ 71.532933][ T9462] print_circular_bug.isra.0.cold+0x163/0x172 [ 71.538978][ T9462] check_noncircular+0x32e/0x3e0 [ 71.543896][ T9462] ? print_circular_bug.isra.0+0x230/0x230 [ 71.549677][ T9462] ? mark_lock+0xc2/0x1220 [ 71.555828][ T9462] ? alloc_list_entry+0xc0/0xc0 [ 71.560792][ T9462] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 71.567108][ T9462] ? find_first_zero_bit+0x9a/0xc0 [ 71.572202][ T9462] __lock_acquire+0x2596/0x4a00 [ 71.577047][ T9462] ? mark_held_locks+0xf0/0xf0 [ 71.581796][ T9462] lock_acquire+0x190/0x410 [ 71.586281][ T9462] ? __might_fault+0xfb/0x1e0 [ 71.590940][ T9462] __might_fault+0x15e/0x1e0 [ 71.595509][ T9462] ? __might_fault+0xfb/0x1e0 [ 71.600163][ T9462] _copy_to_user+0x30/0x160 [ 71.604645][ T9462] mon_bin_read+0x329/0x640 [ 71.609128][ T9462] ? security_file_permission+0x8f/0x380 [ 71.614744][ T9462] __vfs_read+0x8a/0x110 [ 71.618961][ T9462] ? copy_from_buf.isra.0+0x1c0/0x1c0 [ 71.624309][ T9462] vfs_read+0x1f0/0x440 [ 71.628966][ T9462] ksys_read+0x14f/0x290 [ 71.633184][ T9462] ? kernel_write+0x130/0x130 [ 71.637928][ T9462] ? do_syscall_64+0x26/0x760 [ 71.642583][ T9462] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.648625][ T9462] ? do_syscall_64+0x26/0x760 [ 71.653280][ T9462] __x64_sys_read+0x73/0xb0 [ 71.657761][ T9462] do_syscall_64+0xfa/0x760 [ 71.662245][ T9462] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.668121][ T9462] RIP: 0033:0x449ff9 [ 71.671997][ T9462] Code: e8 4c bc 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 71.691580][ T9462] RSP: 002b:00007f378bbbece8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 71.702491][ T9462] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 0000000000449ff9 [ 71.711046][ T9462] RDX: 0000000000000031 RSI: 0000000020000000 RDI: 0000000000000003 [ 71.719083][ T9462] RBP: 00000000006dbc30 R08: 00007f378bbbf700 R09: 0000000000000000 [ 71.727039][ T9462] R10: 00007f378bbbf700 R11: 0000000000000246 R12: 00000000006dbc3c [ 71.734996][ T9462] R13: 00007ffca65092df R14: 00007f378bbbf9c0 R15: 000000000000002d