[?25l[?1c7[ ok 8[?25h[?0c. [....] 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. [ 18.474061] audit: type=1400 audit(1519637885.254:6): avc: denied { map } for pid=4128 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 '10.128.0.29' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 25.089922] audit: type=1400 audit(1519637891.870:7): avc: denied { map } for pid=4142 comm="syzkaller123610" path="/root/syzkaller123610562" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 25.093602] [ 25.115938] audit: type=1400 audit(1519637891.870:8): avc: denied { map } for pid=4142 comm="syzkaller123610" path="/dev/ashmem" dev="devtmpfs" ino=9505 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 25.117458] ====================================================== [ 25.117460] WARNING: possible circular locking dependency detected [ 25.117465] 4.16.0-rc2+ #329 Not tainted [ 25.117467] ------------------------------------------------------ [ 25.117470] syzkaller123610/4142 is trying to acquire lock: [ 25.117472] (&mm->mmap_sem){++++}, at: [<0000000001fb3475>] __might_fault+0xe0/0x1d0 [ 25.117494] [ 25.117494] but task is already holding lock: [ 25.117498] (ashmem_mutex){+.+.}, at: [<00000000fbb27f78>] ashmem_ioctl+0x3db/0x11b0 [ 25.192576] [ 25.192576] which lock already depends on the new lock. [ 25.192576] [ 25.200866] [ 25.200866] the existing dependency chain (in reverse order) is: [ 25.208453] [ 25.208453] -> #1 (ashmem_mutex){+.+.}: [ 25.213894] __mutex_lock+0x16f/0x1a80 [ 25.218277] mutex_lock_nested+0x16/0x20 [ 25.222831] ashmem_mmap+0x53/0x410 [ 25.226952] mmap_region+0xa99/0x15a0 [ 25.231243] do_mmap+0x6c0/0xe00 [ 25.235106] vm_mmap_pgoff+0x1de/0x280 [ 25.239487] SyS_mmap_pgoff+0x462/0x5f0 [ 25.243958] SyS_mmap+0x16/0x20 [ 25.247736] do_syscall_64+0x280/0x940 [ 25.252132] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 25.257822] [ 25.257822] -> #0 (&mm->mmap_sem){++++}: [ 25.263353] lock_acquire+0x1d5/0x580 [ 25.267653] __might_fault+0x13a/0x1d0 [ 25.272043] _copy_from_user+0x2c/0x110 [ 25.276515] ashmem_ioctl+0x438/0x11b0 [ 25.280899] do_vfs_ioctl+0x1b1/0x1520 [ 25.285280] SyS_ioctl+0x8f/0xc0 [ 25.289139] do_syscall_64+0x280/0x940 [ 25.293518] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 25.299195] [ 25.299195] other info that might help us debug this: [ 25.299195] [ 25.307308] Possible unsafe locking scenario: [ 25.307308] [ 25.313331] CPU0 CPU1 [ 25.317963] ---- ---- [ 25.322595] lock(ashmem_mutex); [ 25.326020] lock(&mm->mmap_sem); [ 25.332060] lock(ashmem_mutex); [ 25.337998] lock(&mm->mmap_sem); [ 25.341510] [ 25.341510] *** DEADLOCK *** [ 25.341510] [ 25.347536] 1 lock held by syzkaller123610/4142: [ 25.352255] #0: (ashmem_mutex){+.+.}, at: [<00000000fbb27f78>] ashmem_ioctl+0x3db/0x11b0 [ 25.360638] [ 25.360638] stack backtrace: [ 25.365105] CPU: 1 PID: 4142 Comm: syzkaller123610 Not tainted 4.16.0-rc2+ #329 [ 25.372517] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.381839] Call Trace: [ 25.384401] dump_stack+0x194/0x24d [ 25.388003] ? arch_local_irq_restore+0x53/0x53 [ 25.392654] print_circular_bug.isra.38+0x2cd/0x2dc [ 25.397641] ? save_trace+0xe0/0x2b0 [ 25.401323] __lock_acquire+0x30a8/0x3e00 [ 25.405442] ? ashmem_ioctl+0x3db/0x11b0 [ 25.409477] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.414642] ? __might_sleep+0x95/0x190 [ 25.418588] ? ashmem_ioctl+0x3db/0x11b0 [ 25.422620] ? __mutex_lock+0x16f/0x1a80 [ 25.426650] ? ashmem_ioctl+0x3db/0x11b0 [ 25.430682] ? proc_nr_files+0x60/0x60 [ 25.434541] ? ashmem_ioctl+0x3db/0x11b0 [ 25.438574] ? find_held_lock+0x35/0x1d0 [ 25.442605] ? mutex_lock_io_nested+0x1900/0x1900 [ 25.447421] ? lock_downgrade+0x980/0x980 [ 25.451540] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 25.456355] ? find_held_lock+0x35/0x1d0 [ 25.460386] ? lock_downgrade+0x980/0x980 [ 25.464503] ? vma_set_page_prot+0x16b/0x230 [ 25.468884] lock_acquire+0x1d5/0x580 [ 25.472654] ? lock_acquire+0x1d5/0x580 [ 25.476598] ? __might_fault+0xe0/0x1d0 [ 25.480544] ? lock_release+0xa40/0xa40 [ 25.484490] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 25.490348] ? __might_sleep+0x95/0x190 [ 25.494293] __might_fault+0x13a/0x1d0 [ 25.498150] ? __might_fault+0xe0/0x1d0 [ 25.502099] _copy_from_user+0x2c/0x110 [ 25.506046] ashmem_ioctl+0x438/0x11b0 [ 25.509906] ? ashmem_release+0x190/0x190 [ 25.514030] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 25.519885] ? down_read_killable+0x180/0x180 [ 25.524354] ? rcu_note_context_switch+0x710/0x710 [ 25.529251] ? ashmem_release+0x190/0x190 [ 25.533367] do_vfs_ioctl+0x1b1/0x1520 [ 25.537227] ? ioctl_preallocate+0x2b0/0x2b0 [ 25.541608] ? selinux_capable+0x40/0x40 [ 25.545640] ? putname+0xf3/0x130 [ 25.549065] ? fput+0xd2/0x140 [ 25.552228] ? SyS_mmap_pgoff+0x243/0x5f0 [ 25.556349] ? security_file_ioctl+0x7d/0xb0 [ 25.560725] ? security_file_ioctl+0x89/0xb0 [ 25.565106] SyS_ioctl+0x8f/0xc0 [ 25.568443] ? do_vfs_ioctl+0x1520/0x1520 [ 25.572563] do_syscall_64+0x280/0x940 [ 25.576423] ? __do_page_fault+0xc90/0xc90 [ 25.580629] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 25.585355] ? syscall_return_slowpath+0x550/0x550 [ 25.590256] ? syscall_return_slowpath+0x2ac/0x550 [ 25.595592] ? prepare_exit_to_usermode+0x350/0x350 [ 25.600580] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 25.605914] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.610725] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 25.615889] RIP: 0033:0x43fd19 [ 25.619049] RSP: 002b:00007fffce4552c8 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 [ 25.626730] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd19 [ 25.633972] RDX: 0000000000000000 RSI: 0000000000007709 RDI: 0000000000000003 [ 25.641212]