[....] Starting enhanced syslogd: rsyslogd[ 16.564518] audit: type=1400 audit(1520869681.940:5): avc: denied { syslog } for pid=3997 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?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. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.312760] audit: type=1400 audit(1520869684.688:6): avc: denied { map } for pid=4135 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 '10.128.10.6' (ECDSA) to the list of known hosts. [ 26.102922] audit: type=1400 audit(1520869691.478:7): avc: denied { map } for pid=4149 comm="syz-execprog" path="/root/syz-execprog" dev="sda1" ino=16479 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 2018/03/12 15:48:11 parsed 1 programs 2018/03/12 15:48:11 executed programs: 0 [ 26.337570] audit: type=1400 audit(1520869691.713:8): avc: denied { map } for pid=4149 comm="syz-execprog" path="/root/syzkaller-shm937828241" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:file_t:s0 tclass=file permissive=1 [ 26.348869] IPVS: ftp: loaded support on port[0] = 21 [ 26.395959] ================================================================== [ 26.403427] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 26.409544] Read of size 8 at addr ffff8801d49a96c0 by task syz-executor0/4158 [ 26.416873] [ 26.418478] CPU: 1 PID: 4158 Comm: syz-executor0 Not tainted 4.16.0-rc5+ #261 [ 26.425720] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.435066] Call Trace: [ 26.437644] dump_stack+0x194/0x24d [ 26.441249] ? arch_local_irq_restore+0x53/0x53 [ 26.445893] ? show_regs_print_info+0x18/0x18 [ 26.450362] ? save_stack+0xa3/0xd0 [ 26.453966] ? ucma_close+0x2d7/0x2f0 [ 26.457739] print_address_description+0x73/0x250 [ 26.462554] ? ucma_close+0x2d7/0x2f0 [ 26.466327] kasan_report+0x23c/0x360 [ 26.470127] __asan_report_load8_noabort+0x14/0x20 [ 26.475031] ucma_close+0x2d7/0x2f0 [ 26.478631] ? __might_sleep+0x95/0x190 [ 26.482590] ? ucma_free_ctx+0xd90/0xd90 [ 26.486627] __fput+0x327/0x7e0 [ 26.489882] ? fput+0x140/0x140 [ 26.493138] ? _raw_spin_unlock_irq+0x27/0x70 [ 26.497609] ____fput+0x15/0x20 [ 26.500862] task_work_run+0x199/0x270 [ 26.504739] ? task_work_cancel+0x210/0x210 [ 26.509042] ? _raw_spin_unlock+0x22/0x30 [ 26.513165] ? switch_task_namespaces+0x87/0xc0 [ 26.517814] do_exit+0x9bb/0x1ad0 [ 26.521241] ? ucma_create_id+0x45b/0x620 [ 26.525369] ? mm_update_next_owner+0x930/0x930 [ 26.530015] ? ucma_create_id+0x17b/0x620 [ 26.534140] ? ucma_get_event+0xa90/0xa90 [ 26.538270] ? __might_sleep+0x95/0x190 [ 26.542224] ? kasan_check_write+0x14/0x20 [ 26.546433] ? _copy_from_user+0x99/0x110 [ 26.550555] ? ucma_write+0x11f/0x3d0 [ 26.554325] ? ucma_get_event+0xa90/0xa90 [ 26.558444] ? ucma_resolve_route+0x1a0/0x1a0 [ 26.562918] ? ucma_resolve_route+0x1a0/0x1a0 [ 26.567398] ? __vfs_write+0xf7/0x970 [ 26.571174] ? rcu_note_context_switch+0x710/0x710 [ 26.576079] ? kernel_read+0x120/0x120 [ 26.579940] ? __might_sleep+0x95/0x190 [ 26.583888] ? _cond_resched+0x14/0x30 [ 26.587752] ? __inode_security_revalidate+0xd9/0x130 [ 26.592916] ? avc_policy_seqno+0x9/0x20 [ 26.596957] ? security_file_permission+0x89/0x1e0 [ 26.601867] ? compat_SyS_futex+0x288/0x380 [ 26.606166] ? vfs_write+0x224/0x510 [ 26.609871] do_group_exit+0x149/0x400 [ 26.613732] ? compat_SyS_get_robust_list+0x300/0x300 [ 26.618891] ? SyS_write+0x184/0x220 [ 26.622576] ? __do_page_fault+0x3d6/0xc90 [ 26.626796] ? SyS_exit+0x30/0x30 [ 26.630220] ? SyS_read+0x220/0x220 [ 26.633824] ? do_fast_syscall_32+0x156/0xf9f [ 26.638292] ? do_group_exit+0x400/0x400 [ 26.642326] SyS_exit_group+0x1d/0x20 [ 26.646106] do_fast_syscall_32+0x3ec/0xf9f [ 26.650406] ? do_int80_syscall_32+0x9c0/0x9c0 [ 26.654963] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.659697] ? syscall_return_slowpath+0x2ac/0x550 [ 26.664603] ? prepare_exit_to_usermode+0x350/0x350 [ 26.669609] ? sysret32_from_system_call+0x5/0x3c [ 26.674876] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.679704] entry_SYSENTER_compat+0x70/0x7f [ 26.684087] RIP: 0023:0xf7fbec99 [ 26.687429] RSP: 002b:00000000ff97444c EFLAGS: 00000286 ORIG_RAX: 00000000000000fc [ 26.695114] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 26.702356] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 26.709598] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 26.716840] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 26.724082] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 26.731341] [ 26.732944] Allocated by task 4158: [ 26.736548] save_stack+0x43/0xd0 [ 26.739974] kasan_kmalloc+0xad/0xe0 [ 26.743662] kmem_cache_alloc_trace+0x136/0x740 [ 26.748308] ucma_alloc_ctx+0xce/0x610 [ 26.752169] ucma_create_id+0x205/0x620 [ 26.756115] ucma_write+0x2d6/0x3d0 [ 26.759724] __vfs_write+0xef/0x970 [ 26.763321] vfs_write+0x189/0x510 [ 26.766831] SyS_write+0xef/0x220 [ 26.770259] do_fast_syscall_32+0x3ec/0xf9f [ 26.774567] entry_SYSENTER_compat+0x70/0x7f [ 26.778947] [ 26.780555] Freed by task 4158: [ 26.783828] save_stack+0x43/0xd0 [ 26.787252] __kasan_slab_free+0x11a/0x170 [ 26.791458] kasan_slab_free+0xe/0x10 [ 26.795237] kfree+0xd9/0x260 [ 26.798329] ucma_create_id+0x45b/0x620 [ 26.802277] ucma_write+0x2d6/0x3d0 [ 26.805877] __vfs_write+0xef/0x970 [ 26.809474] vfs_write+0x189/0x510 [ 26.812986] SyS_write+0xef/0x220 [ 26.816415] do_fast_syscall_32+0x3ec/0xf9f [ 26.820709] entry_SYSENTER_compat+0x70/0x7f [ 26.825092] [ 26.826722] The buggy address belongs to the object at ffff8801d49a9640 [ 26.826722] which belongs to the cache kmalloc-256 of size 256 [ 26.839352] The buggy address is located 128 bytes inside of [ 26.839352] 256-byte region [ffff8801d49a9640, ffff8801d49a9740) [ 26.851196] The buggy address belongs to the page: [ 26.856100] page:ffffea0007526a40 count:1 mapcount:0 mapping:ffff8801d49a9000 index:0x0 [ 26.864214] flags: 0x2fffc0000000100(slab) [ 26.868424] raw: 02fffc0000000100 ffff8801d49a9000 0000000000000000 000000010000000c [ 26.876275] raw: ffffea000756ace0 ffffea000754f7a0 ffff8801dac007c0 0000000000000000 [ 26.884124] page dumped because: kasan: bad access detected [ 26.889812] [ 26.891409] Memory state around the buggy address: [ 26.896307] ffff8801d49a9580: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 26.903636] ffff8801d49a9600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 26.910965] >ffff8801d49a9680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.918292] ^ [ 26.923713] ffff8801d49a9700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 26.931044] ffff8801d49a9780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.938374] ================================================================== [ 26.945701] Disabling lock debugging due to kernel taint [ 26.951217] Kernel panic - not syncing: panic_on_warn set ... [ 26.951217] [ 26.958557] CPU: 1 PID: 4158 Comm: syz-executor0 Tainted: G B 4.16.0-rc5+ #261 [ 26.967104] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.976430] Call Trace: [ 26.978995] dump_stack+0x194/0x24d [ 26.982595] ? arch_local_irq_restore+0x53/0x53 [ 26.987239] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.991966] ? vsnprintf+0x1ed/0x1900 [ 26.995738] ? ucma_close+0x240/0x2f0 [ 26.999509] panic+0x1e4/0x41c [ 27.002673] ? refcount_error_report+0x214/0x214 [ 27.007397] ? add_taint+0x1c/0x50 [ 27.010906] ? add_taint+0x1c/0x50 [ 27.014415] ? ucma_close+0x2d7/0x2f0 [ 27.018184] kasan_end_report+0x50/0x50 [ 27.022128] kasan_report+0x149/0x360 [ 27.025900] __asan_report_load8_noabort+0x14/0x20 [ 27.030809] ucma_close+0x2d7/0x2f0 [ 27.034411] ? __might_sleep+0x95/0x190 [ 27.038353] ? ucma_free_ctx+0xd90/0xd90 [ 27.042385] __fput+0x327/0x7e0 [ 27.045637] ? fput+0x140/0x140 [ 27.048887] ? _raw_spin_unlock_irq+0x27/0x70 [ 27.053352] ____fput+0x15/0x20 [ 27.056603] task_work_run+0x199/0x270 [ 27.060461] ? task_work_cancel+0x210/0x210 [ 27.064753] ? _raw_spin_unlock+0x22/0x30 [ 27.068871] ? switch_task_namespaces+0x87/0xc0 [ 27.073512] do_exit+0x9bb/0x1ad0 [ 27.076932] ? ucma_create_id+0x45b/0x620 [ 27.081051] ? mm_update_next_owner+0x930/0x930 [ 27.085689] ? ucma_create_id+0x17b/0x620 [ 27.089805] ? ucma_get_event+0xa90/0xa90 [ 27.093926] ? __might_sleep+0x95/0x190 [ 27.097871] ? kasan_check_write+0x14/0x20 [ 27.102080] ? _copy_from_user+0x99/0x110 [ 27.106199] ? ucma_write+0x11f/0x3d0 [ 27.109968] ? ucma_get_event+0xa90/0xa90 [ 27.114084] ? ucma_resolve_route+0x1a0/0x1a0 [ 27.118552] ? ucma_resolve_route+0x1a0/0x1a0 [ 27.123015] ? __vfs_write+0xf7/0x970 [ 27.126786] ? rcu_note_context_switch+0x710/0x710 [ 27.131685] ? kernel_read+0x120/0x120 [ 27.135542] ? __might_sleep+0x95/0x190 [ 27.139500] ? _cond_resched+0x14/0x30 [ 27.143359] ? __inode_security_revalidate+0xd9/0x130 [ 27.148520] ? avc_policy_seqno+0x9/0x20 [ 27.152556] ? security_file_permission+0x89/0x1e0 [ 27.157461] ? compat_SyS_futex+0x288/0x380 [ 27.161752] ? vfs_write+0x224/0x510 [ 27.165438] do_group_exit+0x149/0x400 [ 27.169294] ? compat_SyS_get_robust_list+0x300/0x300 [ 27.174450] ? SyS_write+0x184/0x220 [ 27.178135] ? __do_page_fault+0x3d6/0xc90 [ 27.182339] ? SyS_exit+0x30/0x30 [ 27.185761] ? SyS_read+0x220/0x220 [ 27.189362] ? do_fast_syscall_32+0x156/0xf9f [ 27.193829] ? do_group_exit+0x400/0x400 [ 27.197860] SyS_exit_group+0x1d/0x20 [ 27.201628] do_fast_syscall_32+0x3ec/0xf9f [ 27.205922] ? do_int80_syscall_32+0x9c0/0x9c0 [ 27.210472] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 27.215199] ? syscall_return_slowpath+0x2ac/0x550 [ 27.220111] ? prepare_exit_to_usermode+0x350/0x350 [ 27.225100] ? sysret32_from_system_call+0x5/0x3c [ 27.229913] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 27.234728] entry_SYSENTER_compat+0x70/0x7f [ 27.239105] RIP: 0023:0xf7fbec99 [ 27.242438] RSP: 002b:00000000ff97444c EFLAGS: 00000286 ORIG_RAX: 00000000000000fc [ 27.250114] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 27.257354] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 27.264593] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 27.271830] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 27.279070] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 27.286698] Dumping ftrace buffer: [ 27.290208] (ftrace buffer empty) [ 27.293891] Kernel Offset: disabled [ 27.297490] Rebooting in 86400 seconds..