[ 42.288948] audit: type=1800 audit(1555704161.244:30): pid=7827 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 46.026909] kauditd_printk_skb: 4 callbacks suppressed [ 46.026925] audit: type=1400 audit(1555704165.014:35): avc: denied { map } for pid=8001 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Warning: Permanently added '10.128.0.177' (ECDSA) to the list of known hosts. executing program [ 52.959537] audit: type=1400 audit(1555704171.944:36): avc: denied { map } for pid=8013 comm="syz-executor865" path="/root/syz-executor865350115" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 52.980696] IPVS: ftp: loaded support on port[0] = 21 [ 53.016225] audit: type=1400 audit(1555704172.004:37): avc: denied { map } for pid=8014 comm="syz-executor865" path="/dev/usbmon0" dev="devtmpfs" ino=15705 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 [ 53.020389] [ 53.043515] ====================================================== [ 53.049821] WARNING: possible circular locking dependency detected [ 53.056155] 4.19.35 #3 Not tainted [ 53.059695] ------------------------------------------------------ [ 53.066017] syz-executor865/8015 is trying to acquire lock: [ 53.071729] 00000000194d7079 (&mm->mmap_sem){++++}, at: __might_fault+0xfb/0x1e0 [ 53.079294] [ 53.079294] but task is already holding lock: [ 53.085301] 0000000092f3f102 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 53.092954] [ 53.092954] which lock already depends on the new lock. [ 53.092954] [ 53.101287] [ 53.101287] the existing dependency chain (in reverse order) is: [ 53.108915] [ 53.108915] -> #1 (&rp->fetch_lock){+.+.}: [ 53.114659] __mutex_lock+0xf7/0x1300 [ 53.119002] mutex_lock_nested+0x16/0x20 [ 53.123595] mon_bin_vma_fault+0x73/0x2d0 [ 53.128295] __do_fault+0x116/0x480 [ 53.132454] __handle_mm_fault+0x2d7d/0x3f80 [ 53.137398] handle_mm_fault+0x43f/0xb30 [ 53.141994] __get_user_pages+0x609/0x1770 [ 53.146788] populate_vma_page_range+0x20d/0x2a0 [ 53.152075] __mm_populate+0x204/0x380 [ 53.156500] vm_mmap_pgoff+0x213/0x230 [ 53.160919] ksys_mmap_pgoff+0x4aa/0x630 [ 53.165522] __x64_sys_mmap+0xe9/0x1b0 [ 53.169953] do_syscall_64+0x103/0x610 [ 53.174376] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.180101] [ 53.180101] -> #0 (&mm->mmap_sem){++++}: [ 53.185688] lock_acquire+0x16f/0x3f0 [ 53.190129] __might_fault+0x15e/0x1e0 [ 53.194559] _copy_to_user+0x30/0x120 [ 53.198893] mon_bin_read+0x329/0x640 [ 53.203231] __vfs_read+0x116/0x800 [ 53.207397] vfs_read+0x194/0x3d0 [ 53.211399] ksys_read+0xea/0x1f0 [ 53.215387] __x64_sys_read+0x73/0xb0 [ 53.219735] do_syscall_64+0x103/0x610 [ 53.224153] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.229862] [ 53.229862] other info that might help us debug this: [ 53.229862] [ 53.238029] Possible unsafe locking scenario: [ 53.238029] [ 53.244109] CPU0 CPU1 [ 53.248786] ---- ---- [ 53.253460] lock(&rp->fetch_lock); [ 53.257183] lock(&mm->mmap_sem); [ 53.263249] lock(&rp->fetch_lock); [ 53.269491] lock(&mm->mmap_sem); [ 53.273031] [ 53.273031] *** DEADLOCK *** [ 53.273031] [ 53.279105] 1 lock held by syz-executor865/8015: [ 53.283853] #0: 0000000092f3f102 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 53.291936] [ 53.291936] stack backtrace: [ 53.296447] CPU: 1 PID: 8015 Comm: syz-executor865 Not tainted 4.19.35 #3 [ 53.303369] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.312735] Call Trace: [ 53.315335] dump_stack+0x172/0x1f0 [ 53.318980] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 53.324364] __lock_acquire+0x2e6d/0x48f0 [ 53.328518] ? mark_held_locks+0xb1/0x100 [ 53.332679] ? mark_held_locks+0x100/0x100 [ 53.336917] ? _raw_spin_unlock_irqrestore+0xa4/0xe0 [ 53.342043] lock_acquire+0x16f/0x3f0 [ 53.345852] ? __might_fault+0xfb/0x1e0 [ 53.349831] __might_fault+0x15e/0x1e0 [ 53.353720] ? __might_fault+0xfb/0x1e0 [ 53.357700] _copy_to_user+0x30/0x120 [ 53.361529] mon_bin_read+0x329/0x640 [ 53.365337] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 53.370883] __vfs_read+0x116/0x800 [ 53.374518] ? copy_from_buf.isra.0+0x1c0/0x1c0 [ 53.379190] ? vfs_copy_file_range+0xba0/0xba0 [ 53.383811] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 53.389360] ? __inode_security_revalidate+0xda/0x120 [ 53.394565] ? avc_policy_seqno+0xd/0x70 [ 53.398638] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 53.403666] ? security_file_permission+0x1ce/0x230 [ 53.408689] ? security_file_permission+0x8f/0x230 [ 53.413621] ? rw_verify_area+0x118/0x360 [ 53.417772] vfs_read+0x194/0x3d0 [ 53.421230] ksys_read+0xea/0x1f0 [ 53.424698] ? kernel_write+0x120/0x120 [ 53.428693] ? do_syscall_64+0x26/0x610 [ 53.432684] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.438057] ? do_syscall_64+0x26/0x610 [ 53.442052] __x64_sys_read+0x73/0xb0 [ 53.445872] do_syscall_64+0x103/0x610 [ 53.449772] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 53.454969] RIP: 0033:0x449f19 [ 53.458167] Code: e8 4c bc 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b d3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 53.477078] RSP: 002b:00007f45598d5ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 53.484812] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000449f19 [ 53.492103] RDX: 000000000000002f RSI: 0000000000000000 RDI: 0000000000000003 [ 53.499388] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 53.506668] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 53.513947] R13: 00007ffe50d915df R14: 00007f45598d69c0 R15: 000000000000002d