[ 44.933963] audit: type=1800 audit(1556223750.553:30): pid=7903 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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: [ 49.949718] kauditd_printk_skb: 4 callbacks suppressed [ 49.949734] audit: type=1400 audit(1556223755.603:35): avc: denied { map } for pid=8077 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 '10.128.1.23' (ECDSA) to the list of known hosts. executing program [ 56.685759] audit: type=1400 audit(1556223762.343:36): avc: denied { map } for pid=8089 comm="syz-executor922" path="/root/syz-executor922515161" 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 [ 56.713884] audit: type=1400 audit(1556223762.373:37): avc: denied { map } for pid=8089 comm="syz-executor922" path="/dev/usbmon0" dev="devtmpfs" ino=15640 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 [ 56.718533] [ 56.741241] ====================================================== [ 56.747541] WARNING: possible circular locking dependency detected [ 56.753841] 4.19.36 #4 Not tainted [ 56.757360] ------------------------------------------------------ [ 56.763659] syz-executor922/8090 is trying to acquire lock: [ 56.769382] 00000000e91fb775 (&mm->mmap_sem){++++}, at: __might_fault+0xfb/0x1e0 [ 56.776919] [ 56.776919] but task is already holding lock: [ 56.782888] 000000003f75fbd6 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 56.790677] [ 56.790677] which lock already depends on the new lock. [ 56.790677] [ 56.799120] [ 56.799120] the existing dependency chain (in reverse order) is: [ 56.806746] [ 56.806746] -> #1 (&rp->fetch_lock){+.+.}: [ 56.812494] __mutex_lock+0xf7/0x1300 [ 56.816815] mutex_lock_nested+0x16/0x20 [ 56.821382] mon_bin_vma_fault+0x73/0x2d0 [ 56.826421] __do_fault+0x116/0x480 [ 56.830555] __handle_mm_fault+0xf72/0x3f80 [ 56.835382] handle_mm_fault+0x43f/0xb30 [ 56.839949] __get_user_pages+0x609/0x1770 [ 56.844690] populate_vma_page_range+0x20d/0x2a0 [ 56.849990] __mm_populate+0x204/0x380 [ 56.854393] vm_mmap_pgoff+0x213/0x230 [ 56.858790] ksys_mmap_pgoff+0x4aa/0x630 [ 56.863393] __x64_sys_mmap+0xe9/0x1b0 [ 56.867786] do_syscall_64+0x103/0x610 [ 56.872200] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 56.877995] [ 56.877995] -> #0 (&mm->mmap_sem){++++}: [ 56.883543] lock_acquire+0x16f/0x3f0 [ 56.887936] __might_fault+0x15e/0x1e0 [ 56.892332] _copy_to_user+0x30/0x120 [ 56.896641] mon_bin_read+0x329/0x640 [ 56.900956] do_iter_read+0x495/0x650 [ 56.905287] vfs_readv+0xf0/0x160 [ 56.909249] do_preadv+0x1c4/0x280 [ 56.913303] __x64_sys_preadv+0x9a/0xf0 [ 56.917783] do_syscall_64+0x103/0x610 [ 56.922179] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 56.927870] [ 56.927870] other info that might help us debug this: [ 56.927870] [ 56.935998] Possible unsafe locking scenario: [ 56.935998] [ 56.942040] CPU0 CPU1 [ 56.946686] ---- ---- [ 56.951345] lock(&rp->fetch_lock); [ 56.955064] lock(&mm->mmap_sem); [ 56.961128] lock(&rp->fetch_lock); [ 56.967342] lock(&mm->mmap_sem); [ 56.970866] [ 56.970866] *** DEADLOCK *** [ 56.970866] [ 56.976908] 1 lock held by syz-executor922/8090: [ 56.981652] #0: 000000003f75fbd6 (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 [ 56.989707] [ 56.989707] stack backtrace: [ 56.994209] CPU: 1 PID: 8090 Comm: syz-executor922 Not tainted 4.19.36 #4 [ 57.001116] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.010582] Call Trace: [ 57.013181] dump_stack+0x172/0x1f0 [ 57.016822] print_circular_bug.isra.0.cold+0x1cc/0x28f [ 57.022180] __lock_acquire+0x2e6d/0x48f0 [ 57.026328] ? mark_held_locks+0x100/0x100 [ 57.030583] ? _raw_spin_unlock_irqrestore+0xa4/0xe0 [ 57.035680] ? __lock_is_held+0xb6/0x140 [ 57.039750] lock_acquire+0x16f/0x3f0 [ 57.043536] ? __might_fault+0xfb/0x1e0 [ 57.047508] __might_fault+0x15e/0x1e0 [ 57.051406] ? __might_fault+0xfb/0x1e0 [ 57.055400] _copy_to_user+0x30/0x120 [ 57.059188] mon_bin_read+0x329/0x640 [ 57.062985] do_iter_read+0x495/0x650 [ 57.066780] ? dup_iter+0x280/0x280 [ 57.070393] vfs_readv+0xf0/0x160 [ 57.073828] ? compat_rw_copy_check_uvector+0x3f0/0x3f0 [ 57.079274] ? kasan_check_read+0x11/0x20 [ 57.083457] ? __fget+0x367/0x540 [ 57.087210] ? iterate_fd+0x360/0x360 [ 57.091001] ? putname+0xef/0x130 [ 57.094550] ? rcu_read_lock_sched_held+0x110/0x130 [ 57.099584] ? kmem_cache_free+0x225/0x260 [ 57.103848] ? __fget_light+0x1a9/0x230 [ 57.107899] do_preadv+0x1c4/0x280 [ 57.111426] ? do_readv+0x290/0x290 [ 57.115039] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.119870] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 57.124614] ? do_syscall_64+0x26/0x610 [ 57.128576] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.133955] ? do_syscall_64+0x26/0x610 [ 57.137943] __x64_sys_preadv+0x9a/0xf0 [ 57.141908] do_syscall_64+0x103/0x610 [ 57.145789] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.150993] RIP: 0033:0x4497c9 [ 57.154175] Code: e8 ec b9 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 ab d6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 57.174436] RSP: 002b:00007f56bdf7ace8 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 [ 57.182224] RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000